Astronomers find 60 Dyson sphere candidates, among millions of searched stars

View larger. | Illustration of a hypothetical Dyson sphere, a partial sphere composed of giant rings around the host star. Image via Kevin Gill/ Wikimedia Commons (CC BY 2.0).

EarthSky’s Will Triggs created this 1-minute video summary for you, of the recent discovery of 60 Dyson sphere candidates.

• If any truly exist, Dyson spheres, or Dyson swarms, are artificial megastructures, built by extraterrestrial civilization to harness their stars’ energy.
• Astronomers have found 60 possible candidates stars, after searching through millions of stars for signs of Dyson spheres.
• The 60 candidate stars range from red dwarfs to larger stars including sun-like stars, up to 6,500 light-years away. All show excesses of infrared heat that, so far, scientists haven’t explained.

60 new Dyson sphere candidates

If they exist, Dyson spheres are gargantuan artificial structures, built by extraterrestrial civilizations around around their stars, with the goal of capturing energy. First proposed in 1960 by physicist Freeman Dyson, they are an incredible thought experiment. But do such objects really exist? Two teams of astronomers in Sweden and Italy recently conducted a new search for possible evidence of Dyson spheres. The astronomers examined 5 million stars, up to 6,500 light-years away. And they found 60 possible candidate stars. The stars, both red dwarfs (or M dwarfs) and larger ones including sun-like stars, are emitting up to 60 times more infrared heat than scientists expected.

However, the results fit with what astronomers would expect to see from Dyson spheres. The teams found the candidates in the latest Gaia DR3 data from the European Gaia satellite as well as the Two Micron All Sky Survey (2MASS) and Wide-field Infrared Survey Explorer (WISE).

The researchers said it is difficult to explain the observations with currently known natural processes. And even if the process is most likely a previously unknown natural phenomenon, it’s still a fascinating discovery.

Jonathan O’Callaghan, a science journalist based in London, wrote about the head-scratching results in New Scientist on May 10, 2024.

Dyson spheres are vast structures that could be used by aliens to capture the energy of a star – and astronomers have found signals from 60 stars in the Milky Way consistent with such devices. https://t.co/Ozyzaqds8B

— New Scientist (@newscientist) May 10, 2024

Two new papers are currently available in the Monthly Notices of the Royal Astronomical Society and arXiv. The first one (May 6, 2024) focuses on seven red dwarf stars, and the second one (March 27, 2024) covers the other 53 stars.

A technosignature hiding in public data

The first paper stated:

Dyson spheres, megastructures that could be constructed by advanced civilizations to harness the radiation energy of their host stars, represent a potential technosignature, that in principle may be hiding in public data already collected as part of large astronomical surveys.

7 Dyson sphere candidates around red dwarfs

The stars studied range from red dwarfs to sun-like stars to ones larger than our sun. Additionally, most of the stars are also older, although a few appear to be young.

Matías Suazo at Uppsala University in Sweden led the team that discovered the seven candidates around red dwarf stars. All these candidates are within 900 light-years of Earth.

Like the second team, they found an excess of infrared radiation around those stars. According to the researchers, the stars appeared up to 60 times brighter in infrared than they expected. This excess infrared radiation is one of the signatures of possible Dyson spheres. The paper said:

Finally, the pipeline identifies seven candidates deserving of further analysis. All of these objects are M dwarfs, for which astrophysical phenomena cannot easily account for the observed infrared excess emission.

There are several natural explanations for the infrared excess in literature, but none of them clearly explains such a phenomenon in the candidates, especially given that all are M dwarfs.

And, as of now, at least, difficult to explain with known natural causes. So, could there be a non-natural explanation? It’s possible, and as Suazo said in New Scientist:

The most fascinating explanation could be actual Dyson spheres.

Unexplained spikes in infrared radiation

As the researchers explained, the spikes in infrared radiation with these seven red dwarfs are consistent with a temperature up to 400 degrees Celsius (750 degrees Fahrenheit). They would, theoretically, be consistent with a partial Dyson sphere, where multiple giant segments or satellites orbit the star instead of one closed sphere. That’s a variation of a Dyson sphere that scientists have also theorized. The New Scientist article said:

This excess infrared heat would have been caused by temperatures of up to 400 degrees Celsius, consistent with what we might expect from a Dyson sphere. Up to 16% of each star would have to be obscured to account for the excess, meaning it would more likely be a variant of the idea called a Dyson swarm – a collection of large satellites orbiting the star to collect energy – if truly of artificial origin.

Co-author Jason Wright at Pennsylvania State University said:

This isn’t like a single solid shell around the star.

View larger. | Photometric images – which measure the light in terms of its perceived brightness to the human eye – of 2 red dwarf Dyson sphere candidates. All images are centered in the position of the candidates, according to Gaia DR3. All sources are clear mid-infrared emitters with no clear contaminators or signatures that indicate an obvious mid-infrared origin. The red circle marks the location of the star according to Gaia DR3. Image via Suazo et al./ Monthly Notices of the Royal Astronomical Society (CC BY 4.0).

53 more candidates

The seven candidates around red dwarf stars are intriguing, but there’s more. Specifically, 53 more candidates, all larger stars, some like our own sun. These were the focus of the second paper. Gabriella Contardo at the International School for Advanced Studies (SISSA) in Italy led this search. These stars are up to 6,500 light-years away. The paper said:

Stellar infrared excesses can indicate various phenomena of interest, from protoplanetary disks to debris disks, or (more speculatively) technosignatures along the lines of Dyson spheres. In this paper, we conduct a large search for such excesses, designed as a data-driven contextual anomaly detection pipeline. We focus our search on FGK stars close to the main sequence to favor non-young host stars. We look for excess in the mid-infrared, unlocking a large sample to search in while favoring extreme infrared excess akin to the ones produced by extreme debris disks.

While most of the stars are older, a few appear to be younger, as the paper noted:

We obtained a set of 53 candidates that display interesting mid-infrared excess. A few of those objects appear to be young stars (showing high hydrogen alpha emission). A significant fraction of our candidates seems to have variability in the optical, and some in the mid-infrared. This can also indicate youth, but a proper age estimation using gyrochronology and a variability analysis is required.

Possible explanations

Scientists don’t know the cause of the excess infrared heat on all these stars. The observations fit with what astronomers have said they would expect to see from Dyson spheres or swarms, based on theoretical studies. Of course, that doesn’t prove these really are alien megastructures … at least not yet. Hot, planet-forming debris disks – protoplanetary disks – are one possibility. The problem is most of the 60 stars are old. Any planet-forming debris disks should have cooled and disappeared by now. That is, of course, apart from possible asteroid belts or Oort clouds, like in our own solar system. But even those are extremely cold environments.

Likewise, another idea is each star just happens to be in front of a more distant galaxy, as seen from Earth. But how likely is that? We don’t know yet.

More observations needed

To be sure, while the observations are difficult to explain with known natural processes, there could still be some other natural mechanism, unknown until now, that would explain them. Only further observations, perhaps by the James Webb Space Telescope, will help scientists figure out what’s really going on. As Contardo noted:

Both sets of candidates are interesting. You need follow-up observations to confirm anything.

Wright added:

Either we’ll rule them all out and say Dyson spheres are quite rare and very hard to find, or they’ll hang around as candidates and we’ll study the heck out of them.

The first paper concluded:

We would like to stress that although our candidates display properties consistent with partial Dyson spheres, it is definitely premature to presume that the mid-infrared presented in these sources originated from them. The mid-infrared data quality for these objects is typically quite low, and we require additional data to determine their nature.

View larger. | Another concept, this one of a Dyson swarm, with many individual smaller panels or satellites surrounding the host star. Image via Vedexent at English Wikipedia/ Wikimedia Commons (CC BY-SA 3.0).

The invention of the Dyson sphere

In the 1960s, physicist and astronomer Freeman J. Dyson proposed the idea of artificial megastructures built by an alien civilization more advanced than our own. Their objective is to capture as much heat from the host star as possible, for energy purposes. Various concepts range from complete spheres around the stars to partial spheres or rings. An alternative to a complete sphere enclosing the star would be a partial sphere. These solar panels would orbit and surround the host star as a Dyson swarm.

Bottom line: Two teams of astronomers in Europe say they have found 60 Dyson sphere candidates. Are they alien megastructures or a previously unknown natural phenomenon?

Source: Project Hephaistos – II. Dyson sphere candidates from Gaia DR3, 2MASS and WISE

Source: A Data-Driven Search For Mid-Infrared Excesses Among Five Million Main-Sequence FGK Stars

Via New Scientist

Read more: A Dyson sphere harvests the energy of stars

Read more: How Gaia could help find Dyson spheres

The post Astronomers find 60 Dyson sphere candidates, among millions of searched stars first appeared on EarthSky.

from EarthSky https://ift.tt/VQaDjcp

View larger. | Illustration of a hypothetical Dyson sphere, a partial sphere composed of giant rings around the host star. Image via Kevin Gill/ Wikimedia Commons (CC BY 2.0).

EarthSky’s Will Triggs created this 1-minute video summary for you, of the recent discovery of 60 Dyson sphere candidates.

• If any truly exist, Dyson spheres, or Dyson swarms, are artificial megastructures, built by extraterrestrial civilization to harness their stars’ energy.
• Astronomers have found 60 possible candidates stars, after searching through millions of stars for signs of Dyson spheres.
• The 60 candidate stars range from red dwarfs to larger stars including sun-like stars, up to 6,500 light-years away. All show excesses of infrared heat that, so far, scientists haven’t explained.

60 new Dyson sphere candidates

If they exist, Dyson spheres are gargantuan artificial structures, built by extraterrestrial civilizations around around their stars, with the goal of capturing energy. First proposed in 1960 by physicist Freeman Dyson, they are an incredible thought experiment. But do such objects really exist? Two teams of astronomers in Sweden and Italy recently conducted a new search for possible evidence of Dyson spheres. The astronomers examined 5 million stars, up to 6,500 light-years away. And they found 60 possible candidate stars. The stars, both red dwarfs (or M dwarfs) and larger ones including sun-like stars, are emitting up to 60 times more infrared heat than scientists expected.

However, the results fit with what astronomers would expect to see from Dyson spheres. The teams found the candidates in the latest Gaia DR3 data from the European Gaia satellite as well as the Two Micron All Sky Survey (2MASS) and Wide-field Infrared Survey Explorer (WISE).

The researchers said it is difficult to explain the observations with currently known natural processes. And even if the process is most likely a previously unknown natural phenomenon, it’s still a fascinating discovery.

Jonathan O’Callaghan, a science journalist based in London, wrote about the head-scratching results in New Scientist on May 10, 2024.

Dyson spheres are vast structures that could be used by aliens to capture the energy of a star – and astronomers have found signals from 60 stars in the Milky Way consistent with such devices. https://t.co/Ozyzaqds8B

— New Scientist (@newscientist) May 10, 2024

Two new papers are currently available in the Monthly Notices of the Royal Astronomical Society and arXiv. The first one (May 6, 2024) focuses on seven red dwarf stars, and the second one (March 27, 2024) covers the other 53 stars.

A technosignature hiding in public data

The first paper stated:

Dyson spheres, megastructures that could be constructed by advanced civilizations to harness the radiation energy of their host stars, represent a potential technosignature, that in principle may be hiding in public data already collected as part of large astronomical surveys.

7 Dyson sphere candidates around red dwarfs

The stars studied range from red dwarfs to sun-like stars to ones larger than our sun. Additionally, most of the stars are also older, although a few appear to be young.

Matías Suazo at Uppsala University in Sweden led the team that discovered the seven candidates around red dwarf stars. All these candidates are within 900 light-years of Earth.

Like the second team, they found an excess of infrared radiation around those stars. According to the researchers, the stars appeared up to 60 times brighter in infrared than they expected. This excess infrared radiation is one of the signatures of possible Dyson spheres. The paper said:

Finally, the pipeline identifies seven candidates deserving of further analysis. All of these objects are M dwarfs, for which astrophysical phenomena cannot easily account for the observed infrared excess emission.

There are several natural explanations for the infrared excess in literature, but none of them clearly explains such a phenomenon in the candidates, especially given that all are M dwarfs.

And, as of now, at least, difficult to explain with known natural causes. So, could there be a non-natural explanation? It’s possible, and as Suazo said in New Scientist:

The most fascinating explanation could be actual Dyson spheres.

Unexplained spikes in infrared radiation

As the researchers explained, the spikes in infrared radiation with these seven red dwarfs are consistent with a temperature up to 400 degrees Celsius (750 degrees Fahrenheit). They would, theoretically, be consistent with a partial Dyson sphere, where multiple giant segments or satellites orbit the star instead of one closed sphere. That’s a variation of a Dyson sphere that scientists have also theorized. The New Scientist article said:

This excess infrared heat would have been caused by temperatures of up to 400 degrees Celsius, consistent with what we might expect from a Dyson sphere. Up to 16% of each star would have to be obscured to account for the excess, meaning it would more likely be a variant of the idea called a Dyson swarm – a collection of large satellites orbiting the star to collect energy – if truly of artificial origin.

Co-author Jason Wright at Pennsylvania State University said:

This isn’t like a single solid shell around the star.

View larger. | Photometric images – which measure the light in terms of its perceived brightness to the human eye – of 2 red dwarf Dyson sphere candidates. All images are centered in the position of the candidates, according to Gaia DR3. All sources are clear mid-infrared emitters with no clear contaminators or signatures that indicate an obvious mid-infrared origin. The red circle marks the location of the star according to Gaia DR3. Image via Suazo et al./ Monthly Notices of the Royal Astronomical Society (CC BY 4.0).

53 more candidates

The seven candidates around red dwarf stars are intriguing, but there’s more. Specifically, 53 more candidates, all larger stars, some like our own sun. These were the focus of the second paper. Gabriella Contardo at the International School for Advanced Studies (SISSA) in Italy led this search. These stars are up to 6,500 light-years away. The paper said:

Stellar infrared excesses can indicate various phenomena of interest, from protoplanetary disks to debris disks, or (more speculatively) technosignatures along the lines of Dyson spheres. In this paper, we conduct a large search for such excesses, designed as a data-driven contextual anomaly detection pipeline. We focus our search on FGK stars close to the main sequence to favor non-young host stars. We look for excess in the mid-infrared, unlocking a large sample to search in while favoring extreme infrared excess akin to the ones produced by extreme debris disks.

While most of the stars are older, a few appear to be younger, as the paper noted:

We obtained a set of 53 candidates that display interesting mid-infrared excess. A few of those objects appear to be young stars (showing high hydrogen alpha emission). A significant fraction of our candidates seems to have variability in the optical, and some in the mid-infrared. This can also indicate youth, but a proper age estimation using gyrochronology and a variability analysis is required.

Possible explanations

Scientists don’t know the cause of the excess infrared heat on all these stars. The observations fit with what astronomers have said they would expect to see from Dyson spheres or swarms, based on theoretical studies. Of course, that doesn’t prove these really are alien megastructures … at least not yet. Hot, planet-forming debris disks – protoplanetary disks – are one possibility. The problem is most of the 60 stars are old. Any planet-forming debris disks should have cooled and disappeared by now. That is, of course, apart from possible asteroid belts or Oort clouds, like in our own solar system. But even those are extremely cold environments.

Likewise, another idea is each star just happens to be in front of a more distant galaxy, as seen from Earth. But how likely is that? We don’t know yet.

More observations needed

To be sure, while the observations are difficult to explain with known natural processes, there could still be some other natural mechanism, unknown until now, that would explain them. Only further observations, perhaps by the James Webb Space Telescope, will help scientists figure out what’s really going on. As Contardo noted:

Both sets of candidates are interesting. You need follow-up observations to confirm anything.

Wright added:

Either we’ll rule them all out and say Dyson spheres are quite rare and very hard to find, or they’ll hang around as candidates and we’ll study the heck out of them.

The first paper concluded:

We would like to stress that although our candidates display properties consistent with partial Dyson spheres, it is definitely premature to presume that the mid-infrared presented in these sources originated from them. The mid-infrared data quality for these objects is typically quite low, and we require additional data to determine their nature.

View larger. | Another concept, this one of a Dyson swarm, with many individual smaller panels or satellites surrounding the host star. Image via Vedexent at English Wikipedia/ Wikimedia Commons (CC BY-SA 3.0).

The invention of the Dyson sphere

In the 1960s, physicist and astronomer Freeman J. Dyson proposed the idea of artificial megastructures built by an alien civilization more advanced than our own. Their objective is to capture as much heat from the host star as possible, for energy purposes. Various concepts range from complete spheres around the stars to partial spheres or rings. An alternative to a complete sphere enclosing the star would be a partial sphere. These solar panels would orbit and surround the host star as a Dyson swarm.

Bottom line: Two teams of astronomers in Europe say they have found 60 Dyson sphere candidates. Are they alien megastructures or a previously unknown natural phenomenon?

Source: Project Hephaistos – II. Dyson sphere candidates from Gaia DR3, 2MASS and WISE

Source: A Data-Driven Search For Mid-Infrared Excesses Among Five Million Main-Sequence FGK Stars

Via New Scientist

Read more: A Dyson sphere harvests the energy of stars

Read more: How Gaia could help find Dyson spheres

The post Astronomers find 60 Dyson sphere candidates, among millions of searched stars first appeared on EarthSky.

from EarthSky https://ift.tt/VQaDjcp

Meet Regulus, Leo the Lion’s Heart

Leo the Lion’s brightest star is Regulus, the Lion’s Heart. Regulus is the dot at the bottom of a backward question mark pattern of stars, called the Sickle. An easily identifiable triangle depicts the Lion’s hindquarters and tail. The star Denebola marks the tail of the Lion. Chart via EarthSky.

Regulus, the brightest star in the constellation Leo the Lion, is a harbinger of spring in the Northern Hemisphere. It crept higher in the sky with each passing day in March and April, as winter favorites like Orion descended westward. And now, in May, this blue-white star is brilliant in the eastern evening sky as soon as the sun goes down.

You can locate Regulus – also known as Alpha Leonis – at the base of a star pattern that appears like a backward question mark. This pattern, known as the Sickle, makes up the head and forequarters of Leo the Lion.

Regulus is also one of three bright stars to make up the asterism known as the Spring Triangle.

Regulus ranks 21st in the list of brightest stars in our sky. However, although it looks like one star to the eye, it’s actually four stars.

A star chart showing the constellation Leo. On the right is a pattern that looks like a flipped question mark, the Sickle. This is the most recognizable pattern to look for when trying to locate Leo in the sky. Image via Torsten Bronger/ Wikimedia Commons (CC BY-SA 3.0).

Regulus is visible most of the year

Around February 18, Regulus was opposite the sun. It rose above the horizon as the sun set, stayed up all night long, and reached its highest point due south (as seen from the Northern Hemisphere) at local midnight. By early April, Regulus was well up in the southeast an hour after sunset. By early June, it’ll be high in the southwest an hour after sunset. Come early July, Regulus will be low to the west an hour after sunset. And from mid-September through mid-February, Regulus will be in the morning sky.

So, Regulus is visible at some time of night throughout the year, except for about a month on either side of August 22. Look towards Regulus around that date and you’ll see the sun.

Planets and the moon pass near it

Regulus is the only 1st magnitude star to sit almost squarely on the ecliptic, which marks the path of the sun, moon and planets across our sky.

So bright planets sometimes pass near Regulus. For example, in early-July 2024, Venus will visit Regulus in the evening sky. And in early-September, 2024, Mercury will join Regulus in the morning twilight. Also, planets can sometimes occult – or pass in front of – Regulus. The last planet to occult Regulus was Venus on July 7, 1959. Then on October 1, 2044, Venus will occult Regulus again.

And, every month, the moon passes near Regulus. In some years, the moon occults this star as seen from Earth. There will be a series of 20 lunar occultations of Regulus from July 2025 to December 2026. During the December 2026 occultation, Mars and Jupiter will be nearby.

A blue, egg-shaped star

Regulus is located about 79 light-years from Earth. It’s a multiple system with at least four component stars. The main star – Regulus A – is large and blue with a spectral type of B8 IVn. Its surface temperature averages about 12,460 kelvin (21,970 degrees F or 12,190 degrees C), which is much higher than our sun’s surface temperature. Regulus A is 3.8 times the mass of our sun, about 4 times as wide, and almost 300 times as bright.

Regulus spins on its axis once every 16 hours. In contrast, our sun spins on its axis about once every 27 days. This fast rotation causes Regulus A to bulge at its equator, so it appears oblate, or egg-shaped. In fact, if Regulus rotated just a bit faster, it would fly apart! And Regulus is not the only star with a fast spin. The stars Altair and Achernar are also fast spinners with flattened, oblate shapes.

Georgia State University’s Center for High Angular Resolution Astronomy (CHARA) created this computer-generated model of Regulus in 2005. Next to it is a model of the sun for scale. The high rotation rate of Regulus creates pronounced equatorial bulging, such that its diameter across its equator (running nearly vertically in this image) is 1/3 longer than its north-south diameter. Image via Wenjin Huang/ Georgia State University/ NSF.

Regulus is 4 stars

Look through a small telescope using at least 50x magnification, and you can see Regulus as two objects separated by 177 arcseconds. The brighter of the pair is called Regulus A.

The fainter one is Regulus B, a cool “orange” dwarf star with a spectral classification of K2 V. The B star has a mass that is 80% of the sun’s, and it’s half as bright. It has a surface temperature of 4,885 kelvin (8,333 F or 4,612 C), and it shines at magnitude 8.1.

Regulus B, meanwhile, has its own companion: Regulus C. At magnitude 13.5, it’s only visible with powerful telescopes. With just 1/3 the mass of the sun, Regulus C is a red dwarf star with a spectral classification of M4 V. Regulus B and C are gravitationally bound to each other, and together they’re called Regulus BC. The distances between B and C ranged from 4.0 to 2.5 arc seconds between 1867 and 1943. There are no recently available measurements.

The fourth star in the system has never been directly resolved via imaging, but its presence is revealed by spectroscopic analysis of Regulus A. Astronomers think it may be a closely orbiting white dwarf star.

You might have heard of a star called Regulus D. This does not refer to the spectroscopic companion of Regulus A, but to a 12th-magnitude star that sits 212 arcseconds from Regulus. For decades, people believed it to be a companion of Regulus, but recent studies from the Gaia satellite show this to be a background star not related to the Regulus system.

A galaxy photobombs Regulus

Situated 1/3 degree north of Regulus is the galaxy Leo 1, you can see it as a faint patch of light in the photo below. Leo 1 is difficult to see due to its proximity to Regulus. Albert George Wilson found it on photographic plates taken as part of the National Geographic Society-Palomar Observatory Sky Survey in 1950. It would be another 40 years before anyone viewed it visually.

Leo 1 is a dwarf galaxy, and a member of our local group. Amateur astronomers can view it, but this requires dark skies and a large telescope.

Regulus as photographed using a telescope. The faint smudge above it is the dwarf galaxy Leo I. Image via Fred Espenak. Used with permission.

A rex by any other name

The name Regulus is from the diminutive form of the Latin rex, meaning little king.

Ancient Arab stargazers called Regulus by the name Qalb al-Asad, which means Heart of the Lion. It also bears the nickname Cor Leonis, again meaning Lion’s Heart. Fittingly, King Richard I of England was also famously known as the Lionheart, or more commonly Couer de Lion in French.

There is a great deal of mythology associated with Leo, perhaps the most common tale being that Leo was the Nemean Lion of the Hercules story. Some Peruvians also knew these stars as the Mountain Lion, whereas in China it was sometimes seen as a horse, and at other times as part of a dragon. Christians in the Middle Ages sometimes referred to it as one of Daniel’s lions.

The larger lion is the constellation Leo, with the star Regulus at its heart, as depicted on a set of constellation cards, Urania’s Mirror, published in London c. 1825. Above it is the faint constellation Leo Minor. Image via Library of Congress/ Wikimedia Commons (public domain).

Bottom line: Regulus, the brightest star in the constellation Leo the Lion, is associated with the arrival of spring and is prominent in May skies. It looks like a single point of light, but is really four stars.

The post Meet Regulus, Leo the Lion’s Heart first appeared on EarthSky.

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Leo the Lion’s brightest star is Regulus, the Lion’s Heart. Regulus is the dot at the bottom of a backward question mark pattern of stars, called the Sickle. An easily identifiable triangle depicts the Lion’s hindquarters and tail. The star Denebola marks the tail of the Lion. Chart via EarthSky.

Regulus, the brightest star in the constellation Leo the Lion, is a harbinger of spring in the Northern Hemisphere. It crept higher in the sky with each passing day in March and April, as winter favorites like Orion descended westward. And now, in May, this blue-white star is brilliant in the eastern evening sky as soon as the sun goes down.

You can locate Regulus – also known as Alpha Leonis – at the base of a star pattern that appears like a backward question mark. This pattern, known as the Sickle, makes up the head and forequarters of Leo the Lion.

Regulus is also one of three bright stars to make up the asterism known as the Spring Triangle.

Regulus ranks 21st in the list of brightest stars in our sky. However, although it looks like one star to the eye, it’s actually four stars.

A star chart showing the constellation Leo. On the right is a pattern that looks like a flipped question mark, the Sickle. This is the most recognizable pattern to look for when trying to locate Leo in the sky. Image via Torsten Bronger/ Wikimedia Commons (CC BY-SA 3.0).

Regulus is visible most of the year

Around February 18, Regulus was opposite the sun. It rose above the horizon as the sun set, stayed up all night long, and reached its highest point due south (as seen from the Northern Hemisphere) at local midnight. By early April, Regulus was well up in the southeast an hour after sunset. By early June, it’ll be high in the southwest an hour after sunset. Come early July, Regulus will be low to the west an hour after sunset. And from mid-September through mid-February, Regulus will be in the morning sky.

So, Regulus is visible at some time of night throughout the year, except for about a month on either side of August 22. Look towards Regulus around that date and you’ll see the sun.

Planets and the moon pass near it

Regulus is the only 1st magnitude star to sit almost squarely on the ecliptic, which marks the path of the sun, moon and planets across our sky.

So bright planets sometimes pass near Regulus. For example, in early-July 2024, Venus will visit Regulus in the evening sky. And in early-September, 2024, Mercury will join Regulus in the morning twilight. Also, planets can sometimes occult – or pass in front of – Regulus. The last planet to occult Regulus was Venus on July 7, 1959. Then on October 1, 2044, Venus will occult Regulus again.

And, every month, the moon passes near Regulus. In some years, the moon occults this star as seen from Earth. There will be a series of 20 lunar occultations of Regulus from July 2025 to December 2026. During the December 2026 occultation, Mars and Jupiter will be nearby.

A blue, egg-shaped star

Regulus is located about 79 light-years from Earth. It’s a multiple system with at least four component stars. The main star – Regulus A – is large and blue with a spectral type of B8 IVn. Its surface temperature averages about 12,460 kelvin (21,970 degrees F or 12,190 degrees C), which is much higher than our sun’s surface temperature. Regulus A is 3.8 times the mass of our sun, about 4 times as wide, and almost 300 times as bright.

Regulus spins on its axis once every 16 hours. In contrast, our sun spins on its axis about once every 27 days. This fast rotation causes Regulus A to bulge at its equator, so it appears oblate, or egg-shaped. In fact, if Regulus rotated just a bit faster, it would fly apart! And Regulus is not the only star with a fast spin. The stars Altair and Achernar are also fast spinners with flattened, oblate shapes.

Georgia State University’s Center for High Angular Resolution Astronomy (CHARA) created this computer-generated model of Regulus in 2005. Next to it is a model of the sun for scale. The high rotation rate of Regulus creates pronounced equatorial bulging, such that its diameter across its equator (running nearly vertically in this image) is 1/3 longer than its north-south diameter. Image via Wenjin Huang/ Georgia State University/ NSF.

Regulus is 4 stars

Look through a small telescope using at least 50x magnification, and you can see Regulus as two objects separated by 177 arcseconds. The brighter of the pair is called Regulus A.

The fainter one is Regulus B, a cool “orange” dwarf star with a spectral classification of K2 V. The B star has a mass that is 80% of the sun’s, and it’s half as bright. It has a surface temperature of 4,885 kelvin (8,333 F or 4,612 C), and it shines at magnitude 8.1.

Regulus B, meanwhile, has its own companion: Regulus C. At magnitude 13.5, it’s only visible with powerful telescopes. With just 1/3 the mass of the sun, Regulus C is a red dwarf star with a spectral classification of M4 V. Regulus B and C are gravitationally bound to each other, and together they’re called Regulus BC. The distances between B and C ranged from 4.0 to 2.5 arc seconds between 1867 and 1943. There are no recently available measurements.

The fourth star in the system has never been directly resolved via imaging, but its presence is revealed by spectroscopic analysis of Regulus A. Astronomers think it may be a closely orbiting white dwarf star.

You might have heard of a star called Regulus D. This does not refer to the spectroscopic companion of Regulus A, but to a 12th-magnitude star that sits 212 arcseconds from Regulus. For decades, people believed it to be a companion of Regulus, but recent studies from the Gaia satellite show this to be a background star not related to the Regulus system.

A galaxy photobombs Regulus

Situated 1/3 degree north of Regulus is the galaxy Leo 1, you can see it as a faint patch of light in the photo below. Leo 1 is difficult to see due to its proximity to Regulus. Albert George Wilson found it on photographic plates taken as part of the National Geographic Society-Palomar Observatory Sky Survey in 1950. It would be another 40 years before anyone viewed it visually.

Leo 1 is a dwarf galaxy, and a member of our local group. Amateur astronomers can view it, but this requires dark skies and a large telescope.

Regulus as photographed using a telescope. The faint smudge above it is the dwarf galaxy Leo I. Image via Fred Espenak. Used with permission.

A rex by any other name

The name Regulus is from the diminutive form of the Latin rex, meaning little king.

Ancient Arab stargazers called Regulus by the name Qalb al-Asad, which means Heart of the Lion. It also bears the nickname Cor Leonis, again meaning Lion’s Heart. Fittingly, King Richard I of England was also famously known as the Lionheart, or more commonly Couer de Lion in French.

There is a great deal of mythology associated with Leo, perhaps the most common tale being that Leo was the Nemean Lion of the Hercules story. Some Peruvians also knew these stars as the Mountain Lion, whereas in China it was sometimes seen as a horse, and at other times as part of a dragon. Christians in the Middle Ages sometimes referred to it as one of Daniel’s lions.

The larger lion is the constellation Leo, with the star Regulus at its heart, as depicted on a set of constellation cards, Urania’s Mirror, published in London c. 1825. Above it is the faint constellation Leo Minor. Image via Library of Congress/ Wikimedia Commons (public domain).

Bottom line: Regulus, the brightest star in the constellation Leo the Lion, is associated with the arrival of spring and is prominent in May skies. It looks like a single point of light, but is really four stars.

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Which Milky Way spiral arm is ours?

How can we visualize ourselves in our home galaxy, the Milky Way? Join EarthSky’s Deborah Byrd and Marcy Curran as they discuss seeing the Milky Way in our sky, and how to understand your place in it.

Which spiral arm of the Milky Way is ours?

Our Milky Way galaxy is the island of stars we call home. If you imagine it as a disk with spiral arms emanating from the center, our sun is approximately halfway from the center to the visible edge. Our solar system lies between two prominent spiral arms: the Perseus Arm and the Scutum-Centaurus Arm. But we aren’t quite free floating in empty space. We lie on the edge of a relatively minor spiral arm, the Orion-Cygnus Arm, or simply, the Orion Arm or Local Arm.

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In Michael Carroll’s book Planet Earth, Past and Present: Parallels Between Our World and its Celestial Neighbors, he explains why our position in the galaxy might be important to life on Earth. He writes:

Our location in the galaxy is significant, as it appears that – like planetary systems – galaxies have habitable zones.

An astonishing 95% of the Milky Way’s suns may not be able to sustain habitable planets, because many orbit the galaxy in paths that carry them through the deadly spiral arms. Any star that passes through one of these starry swarms is subject to deadly radiation from the congested stars. Our own solar system orbits far enough from the center to keep it in sync with the rotation of the rest of the galaxy, so that it remains in the quieter space between the spiral arms. The Earth and its planetary siblings are well placed in a quiet, resource-rich niche of a vast and complex galaxy.

The structure of the Milky Way

The Milky Way is a barred spiral galaxy, which means it has a central bar. There’s still a lot we don’t know about the structure of our galaxy. According to the best current knowledge, the Milky Way is about 100,000 light-years across, about 2,000 light-years deep, and has 100 to 400 billion stars. Astronomers once thought that our spiral galaxy had four major arms, but now they say we have just two major arms and many minor arms.

Where, within this vast spiral structure, do our sun and its planets reside? We’re about 26,000 light-years from the center of the galaxy, on the inner edge of the Orion-Cygnus Arm.

View larger. | Artist’s concept of our Milky Way galaxy. Astronomers now believe the Milky Way galaxy has 2 major arms and many minor arms. Our sun is about halfway from the galactic center, on a minor arm that’s sometimes called the Orion Spur. Image via NASA.

The Orion Arm

The Orion Arm of the Milky Way is probably some 3,500 light-years wide. Initially, astronomers thought it was about 10,000 light-years in length. But a study from 2016 suggests it’s more than 20,000 light-years long.

Astronomers continue to piece together the structure of the Milky Way by painstakingly measuring the positions and distances to many stars and gas clouds. Telescopes on the ground and in space determine distances from parallax measurements. For example, the Gaia Space Telescope’s goal is to provide a 3-dimensional map of our Milky Way.

This Hubble Space Telescope image shows the galaxy UGC 12158. It’s a barred spiral galaxy that scientists think bears a close resemblance to the Milky Way. Image via NASA/ ESA.

How our local spiral arm got its name

The Orion Arm gets its name from the constellation Orion the Hunter, which is one of the most prominent constellations of the Northern Hemisphere winter (Southern Hemisphere summer). Some of the brightest stars and most famous celestial objects of this constellation (Betelgeuse, Rigel, the stars of Orion’s Belt, the Orion nebula) are neighbors to our sun. The reason we see so many bright objects within the constellation Orion is because when we look at it, we’re looking into our own local spiral arm.

View larger. | Artist’s concept of our galactic neighborhood. Some of the best-known astronomical objects in our sky lie in the Orion Arm, along with our sun. Image via R. Hurt/ Wikimedia Commons (public domain).

Bottom line: Where do we live in the Milky Way galaxy? We lie between the major arms in a smaller spiral arm known as the Orion Arm.

The post Which Milky Way spiral arm is ours? first appeared on EarthSky.

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How can we visualize ourselves in our home galaxy, the Milky Way? Join EarthSky’s Deborah Byrd and Marcy Curran as they discuss seeing the Milky Way in our sky, and how to understand your place in it.

Which spiral arm of the Milky Way is ours?

Our Milky Way galaxy is the island of stars we call home. If you imagine it as a disk with spiral arms emanating from the center, our sun is approximately halfway from the center to the visible edge. Our solar system lies between two prominent spiral arms: the Perseus Arm and the Scutum-Centaurus Arm. But we aren’t quite free floating in empty space. We lie on the edge of a relatively minor spiral arm, the Orion-Cygnus Arm, or simply, the Orion Arm or Local Arm.

Join us in making sure everyone has access to the wonders of astronomy. Donate now!

In Michael Carroll’s book Planet Earth, Past and Present: Parallels Between Our World and its Celestial Neighbors, he explains why our position in the galaxy might be important to life on Earth. He writes:

Our location in the galaxy is significant, as it appears that – like planetary systems – galaxies have habitable zones.

An astonishing 95% of the Milky Way’s suns may not be able to sustain habitable planets, because many orbit the galaxy in paths that carry them through the deadly spiral arms. Any star that passes through one of these starry swarms is subject to deadly radiation from the congested stars. Our own solar system orbits far enough from the center to keep it in sync with the rotation of the rest of the galaxy, so that it remains in the quieter space between the spiral arms. The Earth and its planetary siblings are well placed in a quiet, resource-rich niche of a vast and complex galaxy.

The structure of the Milky Way

The Milky Way is a barred spiral galaxy, which means it has a central bar. There’s still a lot we don’t know about the structure of our galaxy. According to the best current knowledge, the Milky Way is about 100,000 light-years across, about 2,000 light-years deep, and has 100 to 400 billion stars. Astronomers once thought that our spiral galaxy had four major arms, but now they say we have just two major arms and many minor arms.

Where, within this vast spiral structure, do our sun and its planets reside? We’re about 26,000 light-years from the center of the galaxy, on the inner edge of the Orion-Cygnus Arm.

View larger. | Artist’s concept of our Milky Way galaxy. Astronomers now believe the Milky Way galaxy has 2 major arms and many minor arms. Our sun is about halfway from the galactic center, on a minor arm that’s sometimes called the Orion Spur. Image via NASA.

The Orion Arm

The Orion Arm of the Milky Way is probably some 3,500 light-years wide. Initially, astronomers thought it was about 10,000 light-years in length. But a study from 2016 suggests it’s more than 20,000 light-years long.

Astronomers continue to piece together the structure of the Milky Way by painstakingly measuring the positions and distances to many stars and gas clouds. Telescopes on the ground and in space determine distances from parallax measurements. For example, the Gaia Space Telescope’s goal is to provide a 3-dimensional map of our Milky Way.

This Hubble Space Telescope image shows the galaxy UGC 12158. It’s a barred spiral galaxy that scientists think bears a close resemblance to the Milky Way. Image via NASA/ ESA.

How our local spiral arm got its name

The Orion Arm gets its name from the constellation Orion the Hunter, which is one of the most prominent constellations of the Northern Hemisphere winter (Southern Hemisphere summer). Some of the brightest stars and most famous celestial objects of this constellation (Betelgeuse, Rigel, the stars of Orion’s Belt, the Orion nebula) are neighbors to our sun. The reason we see so many bright objects within the constellation Orion is because when we look at it, we’re looking into our own local spiral arm.

View larger. | Artist’s concept of our galactic neighborhood. Some of the best-known astronomical objects in our sky lie in the Orion Arm, along with our sun. Image via R. Hurt/ Wikimedia Commons (public domain).

Bottom line: Where do we live in the Milky Way galaxy? We lie between the major arms in a smaller spiral arm known as the Orion Arm.

The post Which Milky Way spiral arm is ours? first appeared on EarthSky.

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Possible atmosphere on rocky exoplanet found for 1st time

View larger. | Is there an atmosphere on rocky exoplanet 55 Cancri e? This is an artist’s concept of 55 Cancri e, 41 light-years from Earth. Analysis by the Webb Space Telescope shows that it likely has a substantial atmosphere of carbon dioxide or carbon monoxide. Image via NASA/ ESA/ CSA/ Ralf Crawford (STScI).

• An international team of astronomers studied rocky exoplanet 55 Cancri e for evidence of an atmosphere. Scientists have long debated whether an atmosphere of any kind existed.
• They found that the planet likely does have a substantial atmosphere of either carbon dioxide or carbon monoxide.
• 55 Cancri e is a super-Earth about twice the size of Earth. It is only 41 light-years away, and extremely hot. In fact, its entire surface is probably covered by molten lava.

Potential atmosphere on rocky exoplanet

For the first time, astronomers say that they have detected a possible atmosphere on a rocky exoplanet. The researchers said on May 8, 2024, that they used the James Webb Space Telescope to make the discovery. Atmospheres have been found and analyzed on a large and growing number of gas giant planets, but those are much easier to detect. This smaller rocky world, 55 Cancri e, is nearby in galactic terms, only 41 light-years from Earth. It is a super-Earth, almost twice the size of Earth. But unlike our planet, it is extremely hot and likely has a molten surface. So while it may be rocky with an atmosphere, it is not like the Earth.

The international research team published its peer-reviewed findings in the journal Nature on May 8, 2024. Read here.

Help spread the wonders of astronomy! Please donate now to EarthSky.org and ensure that people around the world can learn about the night sky and our universe.

This potential discovery is a new milestone for Webb. Finding rocky exoplanets with atmospheres is a major goal for astronomers. Lead author Renyu Hu at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, said:

Webb is pushing the frontiers of exoplanet characterization to rocky planets. It is truly enabling a new type of science.

Atmosphere or no atmosphere?

Astronomers discovered 55 Cancri e in 2011. Since then, scientists have continued to debate if the planet had an atmosphere or not. And if it did, how dense was it? It was possible that 55 Cancri e didn’t have any atmosphere at all. That’s because it orbits only 1.4 million miles (2.3 million km) from its sun-like star. That’s only 1/25 the distance that Mercury is from our sun. Radiation from the star would likely strip the atmosphere away. Also, the planet is probably tidally locked to its star, so that the same side always faces the star. And, it’s extremely hot, about 2,800 degrees Fahrenheit, or 1,540 degrees Celsius. Therefore, its entire surface is likely molten lava.

2 possibilities

If it did have an atmosphere, then scientists said there were two likely possibilities. One was a substantial atmosphere of oxygen, nitrogen and carbon dioxide. The other was a more tenuous atmosphere of vaporized rock, rich in silicon, iron, aluminum and calcium. Now, Webb might finally help answer these questions. As co-author Diana Dragomir, an exoplanet researcher at the University of New Mexico, noted:

I’ve worked on this planet for more than a decade. It’s been really frustrating that none of the observations we’ve been getting have robustly solved these mysteries. I am thrilled that we’re finally getting some answers!

Co-author Yamila Miguel at the Leiden Observatory and the Netherlands Institute for Space Research (SRON) added:

We’ve spent the last 10 years modeling different scenarios, trying to imagine what this world might look like. Finally getting some confirmation of our work is priceless!

View larger. | Secondary eclipse light curve of 55 Cancri e from the MIRI instrument on Webb. The decrease in brightness occurred when the planet moved behind its star, as seen from Earth. Image via NASA/ ESA/ CSA/ Joseph Olmsted (STScI)/ Aaron Bello-Arufe (JPL).

A substantial atmosphere (probably) on rocky exoplanet 55 Cancri e

Webb observed 55 Cancri e with its Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI), using the secondary eclipse spectroscopy method. It looked for subtle changes in the mid-infrared and near-infrared light coming from the planet. The researchers subtracted the brightness of the star itself during the secondary eclipse – when the planet was behind the star – from when the planet was beside the star (light from both the star and planet), as seen from Earth.

Cooler than expected, but still hot

Interestingly, Webb found that the planet is a bit cooler than had been expected. If it had no atmosphere, or only a thin one from vaporized rock, then the temperature on the dayside of the planet would be about 4,000 degrees Fahrenheit (2,200 degrees Celsius). However, with its MIRI instrument, Webb measured a temperature of 2,800 degrees F (1,540 degrees C). That indicated a thicker atmosphere, probably composed of carbon dioxide or carbon monoxide and other volatiles. As Hu said:

Instead, the MIRI data showed a relatively low temperature of about 2,800 degrees Fahrenheit [~1540 degrees Celsius]. This is a very strong indication that energy is being distributed from the dayside to the nightside, most likely by a volatile-rich atmosphere.

The NIRCam instrument provided similar results. Co-author Aaron Bello-Arufe at NASA JPL said:

We see evidence of a dip in the spectrum between 4 and 5 microns; less of this light is reaching the telescope. This suggests the presence of an atmosphere containing carbon monoxide or carbon dioxide, which absorb these wavelengths of light.

View larger. | Emission spectrum of 55 Cancri e, from the MIRI and NIRCam instruments on Webb. The results indicate that the planet likely has a substantial atmosphere of carbon dioxide or carbon monoxide and other volatiles, not just vaporized rock. Image via NASA/ ESA/ CSA/ Joseph Olmsted (STScI)/ Renyu Hu (JPL)/ Aaron Bello-Arufe (JPL)/ Michael Zhang (University of Chicago)/ Mantas Zilinskas (SRON Netherlands Institute for Space Research).

A magma ocean world

Unfortunately for the prospects of life, 55 Cancri e is quite inhospitable. It is so hot that scientists think its surface is a vast magma ocean instead of being solid. Consequently, the atmosphere is likely coming from the interior of the planet, instead of being the original primordial atmosphere from when it first formed. The magma ocean would help to replenish the atmosphere. Bello-Arufe said:

The primary atmosphere would be long gone because of the high temperature and intense radiation from the star. This would be a secondary atmosphere that is continuously replenished by the magma ocean. Magma is not just crystals and liquid rock; there’s a lot of dissolved gas in it, too.

However, the finding shows that rocky planets outside our solar system can indeed maintain atmospheres. If it can happen on 55 Cancri e, then it should also occur on other rocky worlds, including ones more potentially habitable, as Hu noted:

Ultimately, we want to understand what conditions make it possible for a rocky planet to sustain a gas-rich atmosphere: a key ingredient for a habitable planet.

Bottom line: NASA’s Webb telescope has tentatively detected an atmosphere on rocky exoplanet 55 Cancri e, a hot super-Earth world only 41 light-years away.

Source: A secondary atmosphere on the rocky Exoplanet 55 Cancri e

Via NASA

Read more: Habitable exoplanets may have less carbon dioxide

Tatooine exoplanets may be more habitable than we thought

The post Possible atmosphere on rocky exoplanet found for 1st time first appeared on EarthSky.

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View larger. | Is there an atmosphere on rocky exoplanet 55 Cancri e? This is an artist’s concept of 55 Cancri e, 41 light-years from Earth. Analysis by the Webb Space Telescope shows that it likely has a substantial atmosphere of carbon dioxide or carbon monoxide. Image via NASA/ ESA/ CSA/ Ralf Crawford (STScI).

• An international team of astronomers studied rocky exoplanet 55 Cancri e for evidence of an atmosphere. Scientists have long debated whether an atmosphere of any kind existed.
• They found that the planet likely does have a substantial atmosphere of either carbon dioxide or carbon monoxide.
• 55 Cancri e is a super-Earth about twice the size of Earth. It is only 41 light-years away, and extremely hot. In fact, its entire surface is probably covered by molten lava.

Potential atmosphere on rocky exoplanet

For the first time, astronomers say that they have detected a possible atmosphere on a rocky exoplanet. The researchers said on May 8, 2024, that they used the James Webb Space Telescope to make the discovery. Atmospheres have been found and analyzed on a large and growing number of gas giant planets, but those are much easier to detect. This smaller rocky world, 55 Cancri e, is nearby in galactic terms, only 41 light-years from Earth. It is a super-Earth, almost twice the size of Earth. But unlike our planet, it is extremely hot and likely has a molten surface. So while it may be rocky with an atmosphere, it is not like the Earth.

The international research team published its peer-reviewed findings in the journal Nature on May 8, 2024. Read here.

Help spread the wonders of astronomy! Please donate now to EarthSky.org and ensure that people around the world can learn about the night sky and our universe.

This potential discovery is a new milestone for Webb. Finding rocky exoplanets with atmospheres is a major goal for astronomers. Lead author Renyu Hu at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, said:

Webb is pushing the frontiers of exoplanet characterization to rocky planets. It is truly enabling a new type of science.

Atmosphere or no atmosphere?

Astronomers discovered 55 Cancri e in 2011. Since then, scientists have continued to debate if the planet had an atmosphere or not. And if it did, how dense was it? It was possible that 55 Cancri e didn’t have any atmosphere at all. That’s because it orbits only 1.4 million miles (2.3 million km) from its sun-like star. That’s only 1/25 the distance that Mercury is from our sun. Radiation from the star would likely strip the atmosphere away. Also, the planet is probably tidally locked to its star, so that the same side always faces the star. And, it’s extremely hot, about 2,800 degrees Fahrenheit, or 1,540 degrees Celsius. Therefore, its entire surface is likely molten lava.

2 possibilities

If it did have an atmosphere, then scientists said there were two likely possibilities. One was a substantial atmosphere of oxygen, nitrogen and carbon dioxide. The other was a more tenuous atmosphere of vaporized rock, rich in silicon, iron, aluminum and calcium. Now, Webb might finally help answer these questions. As co-author Diana Dragomir, an exoplanet researcher at the University of New Mexico, noted:

I’ve worked on this planet for more than a decade. It’s been really frustrating that none of the observations we’ve been getting have robustly solved these mysteries. I am thrilled that we’re finally getting some answers!

Co-author Yamila Miguel at the Leiden Observatory and the Netherlands Institute for Space Research (SRON) added:

We’ve spent the last 10 years modeling different scenarios, trying to imagine what this world might look like. Finally getting some confirmation of our work is priceless!

View larger. | Secondary eclipse light curve of 55 Cancri e from the MIRI instrument on Webb. The decrease in brightness occurred when the planet moved behind its star, as seen from Earth. Image via NASA/ ESA/ CSA/ Joseph Olmsted (STScI)/ Aaron Bello-Arufe (JPL).

A substantial atmosphere (probably) on rocky exoplanet 55 Cancri e

Webb observed 55 Cancri e with its Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI), using the secondary eclipse spectroscopy method. It looked for subtle changes in the mid-infrared and near-infrared light coming from the planet. The researchers subtracted the brightness of the star itself during the secondary eclipse – when the planet was behind the star – from when the planet was beside the star (light from both the star and planet), as seen from Earth.

Cooler than expected, but still hot

Interestingly, Webb found that the planet is a bit cooler than had been expected. If it had no atmosphere, or only a thin one from vaporized rock, then the temperature on the dayside of the planet would be about 4,000 degrees Fahrenheit (2,200 degrees Celsius). However, with its MIRI instrument, Webb measured a temperature of 2,800 degrees F (1,540 degrees C). That indicated a thicker atmosphere, probably composed of carbon dioxide or carbon monoxide and other volatiles. As Hu said:

Instead, the MIRI data showed a relatively low temperature of about 2,800 degrees Fahrenheit [~1540 degrees Celsius]. This is a very strong indication that energy is being distributed from the dayside to the nightside, most likely by a volatile-rich atmosphere.

The NIRCam instrument provided similar results. Co-author Aaron Bello-Arufe at NASA JPL said:

We see evidence of a dip in the spectrum between 4 and 5 microns; less of this light is reaching the telescope. This suggests the presence of an atmosphere containing carbon monoxide or carbon dioxide, which absorb these wavelengths of light.

View larger. | Emission spectrum of 55 Cancri e, from the MIRI and NIRCam instruments on Webb. The results indicate that the planet likely has a substantial atmosphere of carbon dioxide or carbon monoxide and other volatiles, not just vaporized rock. Image via NASA/ ESA/ CSA/ Joseph Olmsted (STScI)/ Renyu Hu (JPL)/ Aaron Bello-Arufe (JPL)/ Michael Zhang (University of Chicago)/ Mantas Zilinskas (SRON Netherlands Institute for Space Research).

A magma ocean world

Unfortunately for the prospects of life, 55 Cancri e is quite inhospitable. It is so hot that scientists think its surface is a vast magma ocean instead of being solid. Consequently, the atmosphere is likely coming from the interior of the planet, instead of being the original primordial atmosphere from when it first formed. The magma ocean would help to replenish the atmosphere. Bello-Arufe said:

The primary atmosphere would be long gone because of the high temperature and intense radiation from the star. This would be a secondary atmosphere that is continuously replenished by the magma ocean. Magma is not just crystals and liquid rock; there’s a lot of dissolved gas in it, too.

However, the finding shows that rocky planets outside our solar system can indeed maintain atmospheres. If it can happen on 55 Cancri e, then it should also occur on other rocky worlds, including ones more potentially habitable, as Hu noted:

Ultimately, we want to understand what conditions make it possible for a rocky planet to sustain a gas-rich atmosphere: a key ingredient for a habitable planet.

Bottom line: NASA’s Webb telescope has tentatively detected an atmosphere on rocky exoplanet 55 Cancri e, a hot super-Earth world only 41 light-years away.

Source: A secondary atmosphere on the rocky Exoplanet 55 Cancri e

Via NASA

Read more: Habitable exoplanets may have less carbon dioxide

Tatooine exoplanets may be more habitable than we thought

The post Possible atmosphere on rocky exoplanet found for 1st time first appeared on EarthSky.

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Will La Niña pump up this year’s hurricane season?

Here’s devastating and deadly Hurricane Katrina on August 28, 2005. For this upcoming Atlantic hurricane season, we’ll be transitioning from El Niño conditions to La Niña conditions. What will that mean for hurricane season in 2024? Find out here. Image via NASA.

One of the big contributors to the record-breaking global temperatures over the past year – El Niño – is nearly gone. And its opposite, La Niña, is on the way.

Whether that’s a relief or not depends in part on where you live. Above-normal temperatures are still forecast across the U.S. in summer 2024. And if you live along the U.S. Atlantic or Gulf Coasts, La Niña can contribute to the worst possible combination of climate conditions for fueling hurricanes.

Pedro DiNezio, an atmosphere and ocean scientist at the University of Colorado who studies El Niño and La Niña, explains why and what’s ahead.

Please help EarthSky keep going! Our annual crowd-funder is going on now. PLEASE DONATE today to continue enjoying updates on your cosmos and world.

By Pedro DiNezio, University of Colorado Boulder

What is La Niña?

La Niña and El Niño are the two extremes of a recurring climate pattern that can affect weather around the world.

Forecasters know La Niña has arrived when temperatures in the eastern Pacific Ocean along the equator west of South America cool by at least half a degree Celsius (0.9 Fahrenheit) below normal. During El Niño, the same region warms instead.

Those temperature fluctuations might seem small, but they can affect the atmosphere in ways that ripple across the planet.

How La Nina and El Nino form. NOAA.

Atmospheric circulation

The tropics have an atmospheric circulation pattern called the Walker Circulation, named after Sir Gilbert Walker, an English physicist in the early 20th century. The Walker Circulation is basically giant loops of air rising and descending in different parts of the tropics.

Normally, air rises over the Amazon and Indonesia because moisture from the tropical forests makes the air more buoyant there, and it comes down in East Africa and the eastern Pacific. During La Niña, those loops intensify, generating stormier conditions where they rise and drier conditions where they descend. And during El Niño, ocean heat in the eastern Pacific instead shifts those loops, so the eastern Pacific gets stormier.

During La Niña, the Walker Circulation intensifies, triggering stronger storms where the air rises. Image via Fiona Martin/ NOAA/ Climate.gov.

During El Niño, the Walker Circulation shifts eastward, so more storms form off California as warm air rises over the warmer waters of the eastern Pacific. Image via Fiona Martin, NOAA Climate.gov.

A transition from El Niño to #ENSO-neutral is likely in the next month. La Niña may develop in June-August (49% chance) or July-September (69% chance). An #ElNino Advisory and #LaNina Watch remain in effect. https://t.co/5zlzaZ1aZx pic.twitter.com/exrBOWBcCR

— NWS Climate Prediction Center (@NWSCPC) May 9, 2024

The jet stream

EL Niño and La Niña also affect the jet stream, a strong current of air that blows from west to east across the U.S. and other mid-latitude regions.

During El Niño, the jet stream tends to push storms toward the subtropics, making these typically dry areas wetter. Conversely, mid-latitude regions that normally would get the storms become drier because storms shift away.

This year, forecasters expect a fast transition to La Niña, likely by late summer. After a strong El Niño, like the world saw in late 2023 and early 2024, conditions tend to swing fairly quickly to La Niña. How long it will stick around is an open question. This cycle tends to swing from extreme to extreme every three to seven years on average. But while El Niños tend to be short-lived, La Niñas can last two years or longer.

How does La Niña affect hurricanes?

Temperatures in the tropical Pacific also control wind shear over large parts of the Atlantic Ocean.

Wind shear is a difference in wind speeds at different heights or direction. Hurricanes have a harder time holding their column structure during strong wind shear because stronger winds higher up push the column apart.

La Niña produces less wind shear, removing a brake on hurricanes. That’s not good news for people living in hurricane-prone regions like Florida. In 2020, during the last La Niña, the Atlantic saw a record 30 tropical storms and 14 hurricanes, and 2021 had 21 tropical storms and seven hurricanes.

Forecasters are already warning that this year’s Atlantic storm season could rival 2021, due in large part to La Niña. The tropical Atlantic has also been exceptionally warm, with sea surface temperature-breaking records for over a year. That warmth affects the atmosphere, causing more atmospheric motion over the Atlantic, fueling hurricanes.

Some of the online discourse around mainstream coverage of outlooks for a very active Atlantic hurricane season has been along the lines of "they say that every year".

Comparing all April-issued CSU hurricane season outlooks, this is the most active forecast they've made yet: pic.twitter.com/vLFYE0yMMx

— Tomer Burg (@burgwx) May 5, 2024

Comparing March 2024 SST's in the Tropical Atlantic with other active hurricane seasons. SST's can change quickly – and we will still see changes as we head into hurricane season – but these years ultimately produced large numbers of storms. (Season named storm # on right). pic.twitter.com/QxhqQkw5NW

— Jeff Berardelli (@WeatherProf) April 23, 2024

Will drought return to the US Southwest?

The U.S. Southwest’s water supplies will probably be okay for the first year of La Niña because of all the rain over the past winter. But the second year tends to become problematic. A third year, as the region saw in 2022, can lead to severe water shortages.

Drier conditions also fuel more extreme fire seasons in the West, particularly in the fall, when the winds pick up.

During La Niña, the jet stream tends to be farther north, causing drier conditions across the U.S. Southwest. Image via NOAA/ Climate.gov.

What happens in the Southern Hemisphere during La Niña?

The impacts of El Niño and La Niña are almost a mirror image in the Southern Hemisphere.

Chile and Argentina tend to get drought during La Niña, while the same phase leads to more rain in the Amazon. Australia had severe flooding during the last La Niña. La Niña also favors the Indian monsoon, meaning above-average rainfall. The effects aren’t immediate, however. In South Asia, for example, the changes tend to show up a few months after La Niña has officially appeared.

La Niña is quite bad for eastern Africa, where vulnerable communities are already in a long-term drought.

Typical La Niña climate impacts, though conditions aren’t always like this. Image via NOAA/ Climate.gov.

What about climate change?

El Niño and La Niña are now happening on top of the effects of global warming. That can exacerbate temperatures, as the world saw in 2023, and precipitation can go off the charts.

Since summer 2023, the world has had 10 straight months of record-breaking global temperatures. A lot of that warmth is coming from the oceans, which are still at record-high temperatures.

La Niña should cool things a bit, but greenhouse gas emissions that drive global warming are still rising in the background. So while fluctuations between El Niño and La Niña can cause short-term temperature swings, the overall trend is toward a warming world.

The image is a little outdated, here’s the up to date data, which is unchanged. pic.twitter.com/3GCsf9l8f6

— Dylan Federico (@DylanFedericoWX) May 7, 2024

Pedro DiNezio, Associate Professor of Atmospheric and Ocean Sciences, University of Colorado Boulder

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Bottom line: Will the coming La Niña conditions mean this year’s hurricane season will overperform? Find out how La Niña affects hurricane formation.

Read more: 2024 Atlantic hurricane outlook and list of names

The post Will La Niña pump up this year’s hurricane season? first appeared on EarthSky.

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Here’s devastating and deadly Hurricane Katrina on August 28, 2005. For this upcoming Atlantic hurricane season, we’ll be transitioning from El Niño conditions to La Niña conditions. What will that mean for hurricane season in 2024? Find out here. Image via NASA.

One of the big contributors to the record-breaking global temperatures over the past year – El Niño – is nearly gone. And its opposite, La Niña, is on the way.

Whether that’s a relief or not depends in part on where you live. Above-normal temperatures are still forecast across the U.S. in summer 2024. And if you live along the U.S. Atlantic or Gulf Coasts, La Niña can contribute to the worst possible combination of climate conditions for fueling hurricanes.

Pedro DiNezio, an atmosphere and ocean scientist at the University of Colorado who studies El Niño and La Niña, explains why and what’s ahead.

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By Pedro DiNezio, University of Colorado Boulder

What is La Niña?

La Niña and El Niño are the two extremes of a recurring climate pattern that can affect weather around the world.

Forecasters know La Niña has arrived when temperatures in the eastern Pacific Ocean along the equator west of South America cool by at least half a degree Celsius (0.9 Fahrenheit) below normal. During El Niño, the same region warms instead.

Those temperature fluctuations might seem small, but they can affect the atmosphere in ways that ripple across the planet.

How La Nina and El Nino form. NOAA.

Atmospheric circulation

The tropics have an atmospheric circulation pattern called the Walker Circulation, named after Sir Gilbert Walker, an English physicist in the early 20th century. The Walker Circulation is basically giant loops of air rising and descending in different parts of the tropics.

Normally, air rises over the Amazon and Indonesia because moisture from the tropical forests makes the air more buoyant there, and it comes down in East Africa and the eastern Pacific. During La Niña, those loops intensify, generating stormier conditions where they rise and drier conditions where they descend. And during El Niño, ocean heat in the eastern Pacific instead shifts those loops, so the eastern Pacific gets stormier.

During La Niña, the Walker Circulation intensifies, triggering stronger storms where the air rises. Image via Fiona Martin/ NOAA/ Climate.gov.

During El Niño, the Walker Circulation shifts eastward, so more storms form off California as warm air rises over the warmer waters of the eastern Pacific. Image via Fiona Martin, NOAA Climate.gov.

A transition from El Niño to #ENSO-neutral is likely in the next month. La Niña may develop in June-August (49% chance) or July-September (69% chance). An #ElNino Advisory and #LaNina Watch remain in effect. https://t.co/5zlzaZ1aZx pic.twitter.com/exrBOWBcCR

— NWS Climate Prediction Center (@NWSCPC) May 9, 2024

The jet stream

EL Niño and La Niña also affect the jet stream, a strong current of air that blows from west to east across the U.S. and other mid-latitude regions.

During El Niño, the jet stream tends to push storms toward the subtropics, making these typically dry areas wetter. Conversely, mid-latitude regions that normally would get the storms become drier because storms shift away.

This year, forecasters expect a fast transition to La Niña, likely by late summer. After a strong El Niño, like the world saw in late 2023 and early 2024, conditions tend to swing fairly quickly to La Niña. How long it will stick around is an open question. This cycle tends to swing from extreme to extreme every three to seven years on average. But while El Niños tend to be short-lived, La Niñas can last two years or longer.

How does La Niña affect hurricanes?

Temperatures in the tropical Pacific also control wind shear over large parts of the Atlantic Ocean.

Wind shear is a difference in wind speeds at different heights or direction. Hurricanes have a harder time holding their column structure during strong wind shear because stronger winds higher up push the column apart.

La Niña produces less wind shear, removing a brake on hurricanes. That’s not good news for people living in hurricane-prone regions like Florida. In 2020, during the last La Niña, the Atlantic saw a record 30 tropical storms and 14 hurricanes, and 2021 had 21 tropical storms and seven hurricanes.

Forecasters are already warning that this year’s Atlantic storm season could rival 2021, due in large part to La Niña. The tropical Atlantic has also been exceptionally warm, with sea surface temperature-breaking records for over a year. That warmth affects the atmosphere, causing more atmospheric motion over the Atlantic, fueling hurricanes.

Some of the online discourse around mainstream coverage of outlooks for a very active Atlantic hurricane season has been along the lines of "they say that every year".

Comparing all April-issued CSU hurricane season outlooks, this is the most active forecast they've made yet: pic.twitter.com/vLFYE0yMMx

— Tomer Burg (@burgwx) May 5, 2024

Comparing March 2024 SST's in the Tropical Atlantic with other active hurricane seasons. SST's can change quickly – and we will still see changes as we head into hurricane season – but these years ultimately produced large numbers of storms. (Season named storm # on right). pic.twitter.com/QxhqQkw5NW

— Jeff Berardelli (@WeatherProf) April 23, 2024

Will drought return to the US Southwest?

The U.S. Southwest’s water supplies will probably be okay for the first year of La Niña because of all the rain over the past winter. But the second year tends to become problematic. A third year, as the region saw in 2022, can lead to severe water shortages.

Drier conditions also fuel more extreme fire seasons in the West, particularly in the fall, when the winds pick up.

During La Niña, the jet stream tends to be farther north, causing drier conditions across the U.S. Southwest. Image via NOAA/ Climate.gov.

What happens in the Southern Hemisphere during La Niña?

The impacts of El Niño and La Niña are almost a mirror image in the Southern Hemisphere.

Chile and Argentina tend to get drought during La Niña, while the same phase leads to more rain in the Amazon. Australia had severe flooding during the last La Niña. La Niña also favors the Indian monsoon, meaning above-average rainfall. The effects aren’t immediate, however. In South Asia, for example, the changes tend to show up a few months after La Niña has officially appeared.

La Niña is quite bad for eastern Africa, where vulnerable communities are already in a long-term drought.

Typical La Niña climate impacts, though conditions aren’t always like this. Image via NOAA/ Climate.gov.

What about climate change?

El Niño and La Niña are now happening on top of the effects of global warming. That can exacerbate temperatures, as the world saw in 2023, and precipitation can go off the charts.

Since summer 2023, the world has had 10 straight months of record-breaking global temperatures. A lot of that warmth is coming from the oceans, which are still at record-high temperatures.

La Niña should cool things a bit, but greenhouse gas emissions that drive global warming are still rising in the background. So while fluctuations between El Niño and La Niña can cause short-term temperature swings, the overall trend is toward a warming world.

The image is a little outdated, here’s the up to date data, which is unchanged. pic.twitter.com/3GCsf9l8f6

— Dylan Federico (@DylanFedericoWX) May 7, 2024

Pedro DiNezio, Associate Professor of Atmospheric and Ocean Sciences, University of Colorado Boulder

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Bottom line: Will the coming La Niña conditions mean this year’s hurricane season will overperform? Find out how La Niña affects hurricane formation.

Read more: 2024 Atlantic hurricane outlook and list of names

The post Will La Niña pump up this year’s hurricane season? first appeared on EarthSky.

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Carnivorous plants are our lifeform of the week

When we think of carnivorous beings, images of large fangs and sharp claws come to mind. But what about carnivorous plants? Even though their name indicates that they are carnivorous, the vast majority only feed on insects.

There are around 700 species of carnivorous plants and some of them can hunt animals larger than insects, such as rats, frogs, or lizards. You might wonder, how can these plants trap prey? The surface of their leaves is extremely sensitive. Therefore, any pressure triggers a change in the water pressure of the leaf cells. That change translates into movement. The cells expand or contract and cause motion. That’s how their mouths open and close, or how their tentacles extend and trap their prey.

The Venus flytrap is one of the most famous carnivorous plants. Image via Rapha Wilde/ Unsplash.

They are classified into five groups depending on the way they capture their prey.

Please help EarthSky keep going! Our annual crowd-funder is going on now. PLEASE DONATE today to continue enjoying updates on your cosmos and world.

Snap traps

Snap traps close their “mouths.” They are probably the most well-known type of carnivorous plant. Snap trap plants have leaves for mouths that release nectar on their edges to attract prey. When the prey approaches and touches the hairs or filaments inside the mouth, it closes, trapping the prey.

The Venus flytrap is one of the most famous carnivorous plants and is a snap trap plant. It has sensory hairs or filaments inside the mouth – between three and six on the surface of each leaf – that indicate to the leaf when to close. So, yes! Plants also produce electrical signals even though they lack a nervous system. The mouth only closes when the prey touches the filaments at least twice in less than 20 seconds, so as not to confuse it with a drop of water.

A Venus flytrap. The “mouth” has from 3 to 6 filaments on the surface of each leaf. Image via Rapha Wilde/ Unsplash.

Sticky traps

Sticky traps (or flypaper traps) have leaves with hairs or filaments that produce nectar – that looks like dew or water drops at the top of the hairs – to attract prey. But this nectar is also sticky like glue. When the prey, attracted by the nectar, gets to the plant, it is trapped by the glue. Some plants have tentacle-like leaves that not only have the sticky filaments, but that can also wrap around the prey like an octopus.

Sticky traps seduce and kill with a sweet, sticky nectar. Image via Dean Erasmus/ Unsplash.

Pitcher plants

Pitcher plants (or pitfall traps) are jug-shaped and possess an incredible structure. Some of them have tendrils that fall down, then turn back up and transform into leaves that are completely closed at the bottom. The bottom of the jug fills with sweet, delicious nectar to attract prey. And it also fills with digestive enzymes to decompose prey. Also, these plants have a lid at the top. When they are digesting their prey, the lid closes.

Pitcher plants have a liquid at the bottom to drown its prey. image via JeremiahsCPs/ Wikipedia (public domain).

Light trap

A light trap (or lobster trap) plant also attracts prey with nectar, which is located at the bottom. In this case, the prey enters the plant, that has sort of a window that allows light to enter the plant. The prey gets deeper into the plant, following the light and the nectar, and can’t find the way back to the dark entry.

Inward hairs

Inward hairs (or pigeon traps) have hairs where the prey enters. Once inside the trap, the prey can’t escape past the hairs.

How is prey digested?

Carnivorous plants produce nectar to attract prey, then use acids to dissolve their victims, and enzymes to digest them. Enzymes are a type of protein that act as catalysts and regulators of chemical reactions.

Once the plant begins to produce digestive enzymes to decompose and digest the prey, there are other glands in the plant that begin to function. They absorb the solution that has been produced, and with it, the nutrients that the plant needs. Not a drop is wasted in the entire process.

How long does it take to digest its prey?

The most curious thing about these plants is that it can take more than two weeks for them to digest any insect, while humans only need about two days to completely digest food.

But even if their digestion is slow, the mouths and lids are quite fast! According to a study from the National Institute of Health:

It was shown using high-speed video under ultraviolet light that the fast closure of Venus flytrap starts at about 40 milliseconds after mechanical stimulation and completes in 0.3–0.7 s.

This is a type of pitcher plant. Carnivorous plants produce nectar to attract prey, acids to dissolve their victims, and enzymes to digest them. Image via Rapha Wilde/ Unsplash.

How did they become carnivorous?

Let’s not forget that, in the end, these carnivorous plants are still plants. So, yes, they do go through a normal photosynthesis process, which converts light into chemical energy. This process requires not only sunlight, but also water, carbon dioxide, and nutrients such as nitrogen. But carnivorous plants usually live in swampy places, such as bogs and wetlands, areas that have little nitrogen and an acidic pH. That’s why they evolved into carnivores.

Plants get nutrients from the soil through their roots. But if the soil quality isn’t good enough, with areas low in nitrogen, then the carnivorous plants need to supplement nitrogen by eating insects or animals.

But trapping and digesting prey require energy, which leaves less energy for photosynthesis. Consequently, carnivorous plants photosynthesize at significantly lower rates than regular plants. Still, these plants need ample sunlight.

Curious things about them

Most carnivorous plants respect pollinating insects. Like many other plants, carnivorous plants need pollinators, though some carnivorous plants can self-pollinate. If carnivorous plants feed on insects, how do they differentiate pollinators from non-pollinators? That’s where the magic of nature comes in to play.

Logically, the plants don’t know which insect is approaching. So, they grow a very long stem, far away from their traps, and right at the top, there is an attractive flower for the beloved pollinators.

Many carnivorous plants avoid trapping the much appreciated pollinators with a flower that is far away from their traps. Image via Juliana Barquero/ Unsplash.

Some even hibernate

Some carnivorous plants of tropical origin hibernate during winter. Although their behavior varies depending on the species, they usually shed their leaves to sprout again with the arrival of spring. This is a protective mechanism that enables the plant to survive in various climates. So, if you have one and it stops growing in winter, now you know why.

There are some species that live submerged in water. In this case, the base of the plant is submerged while the stems with traps are on the surface. How cool! This is how they feed.

Can you grow them at home?

Although they are wild plants, if you replicate the conditions in which they live, they can be grown at home. Study the type of plant and its needs before purchasing one. These plants are delicate and require specific care. You should know that some carnivorous plants survive well in cold climates, but the vast majority live in tropical and humid climates.

The soil for carnivorous plants should have few nutrients and not be fertilized. Make sure the plant has enough humidity and plenty of sunlight. If you live in a cold place, it is advisable to keep the plant indoors and create a small greenhouse to maintain humidity and warmth.

Instead of watering it from the top, place a deep container of water under the pot and let it absorb water. When the surface of the pot is wet, you can remove the container. Use distilled water or rainwater to avoid any additives found in tap water.

The plant’s feeding habits depend on the type of plant. Keep in mind that some species ONLY need sunlight and water to live.

When the plant moves, like when closing its mouths, it uses a lot of energy. So don’t play with your plant to make it close its mouths on purpose, it will lose a lot of energy and won’t receive any nutrients. It needs that energy to survive.

In many cases, you won’t have to feed it because the plant has its own system for attracting insects. If your plant is indoors and doesn’t have access to any insects, you can feed it, but take into account that it may take up to two weeks for your plant to digest the insect you offer it.

Read more: Water lilies, beautiful and colorful: Lifeform of the week

Bottom line: Beware of carnivorous plants! There are hundreds of species and they are deadly, but mostly to insects. The structure of their traps is foolproof.

The post Carnivorous plants are our lifeform of the week first appeared on EarthSky.

from EarthSky https://ift.tt/oXzjvwr

When we think of carnivorous beings, images of large fangs and sharp claws come to mind. But what about carnivorous plants? Even though their name indicates that they are carnivorous, the vast majority only feed on insects.

There are around 700 species of carnivorous plants and some of them can hunt animals larger than insects, such as rats, frogs, or lizards. You might wonder, how can these plants trap prey? The surface of their leaves is extremely sensitive. Therefore, any pressure triggers a change in the water pressure of the leaf cells. That change translates into movement. The cells expand or contract and cause motion. That’s how their mouths open and close, or how their tentacles extend and trap their prey.

The Venus flytrap is one of the most famous carnivorous plants. Image via Rapha Wilde/ Unsplash.

They are classified into five groups depending on the way they capture their prey.

Please help EarthSky keep going! Our annual crowd-funder is going on now. PLEASE DONATE today to continue enjoying updates on your cosmos and world.

Snap traps

Snap traps close their “mouths.” They are probably the most well-known type of carnivorous plant. Snap trap plants have leaves for mouths that release nectar on their edges to attract prey. When the prey approaches and touches the hairs or filaments inside the mouth, it closes, trapping the prey.

The Venus flytrap is one of the most famous carnivorous plants and is a snap trap plant. It has sensory hairs or filaments inside the mouth – between three and six on the surface of each leaf – that indicate to the leaf when to close. So, yes! Plants also produce electrical signals even though they lack a nervous system. The mouth only closes when the prey touches the filaments at least twice in less than 20 seconds, so as not to confuse it with a drop of water.

A Venus flytrap. The “mouth” has from 3 to 6 filaments on the surface of each leaf. Image via Rapha Wilde/ Unsplash.

Sticky traps

Sticky traps (or flypaper traps) have leaves with hairs or filaments that produce nectar – that looks like dew or water drops at the top of the hairs – to attract prey. But this nectar is also sticky like glue. When the prey, attracted by the nectar, gets to the plant, it is trapped by the glue. Some plants have tentacle-like leaves that not only have the sticky filaments, but that can also wrap around the prey like an octopus.

Sticky traps seduce and kill with a sweet, sticky nectar. Image via Dean Erasmus/ Unsplash.

Pitcher plants

Pitcher plants (or pitfall traps) are jug-shaped and possess an incredible structure. Some of them have tendrils that fall down, then turn back up and transform into leaves that are completely closed at the bottom. The bottom of the jug fills with sweet, delicious nectar to attract prey. And it also fills with digestive enzymes to decompose prey. Also, these plants have a lid at the top. When they are digesting their prey, the lid closes.

Pitcher plants have a liquid at the bottom to drown its prey. image via JeremiahsCPs/ Wikipedia (public domain).

Light trap

A light trap (or lobster trap) plant also attracts prey with nectar, which is located at the bottom. In this case, the prey enters the plant, that has sort of a window that allows light to enter the plant. The prey gets deeper into the plant, following the light and the nectar, and can’t find the way back to the dark entry.

Inward hairs

Inward hairs (or pigeon traps) have hairs where the prey enters. Once inside the trap, the prey can’t escape past the hairs.

How is prey digested?

Carnivorous plants produce nectar to attract prey, then use acids to dissolve their victims, and enzymes to digest them. Enzymes are a type of protein that act as catalysts and regulators of chemical reactions.

Once the plant begins to produce digestive enzymes to decompose and digest the prey, there are other glands in the plant that begin to function. They absorb the solution that has been produced, and with it, the nutrients that the plant needs. Not a drop is wasted in the entire process.

How long does it take to digest its prey?

The most curious thing about these plants is that it can take more than two weeks for them to digest any insect, while humans only need about two days to completely digest food.

But even if their digestion is slow, the mouths and lids are quite fast! According to a study from the National Institute of Health:

It was shown using high-speed video under ultraviolet light that the fast closure of Venus flytrap starts at about 40 milliseconds after mechanical stimulation and completes in 0.3–0.7 s.

This is a type of pitcher plant. Carnivorous plants produce nectar to attract prey, acids to dissolve their victims, and enzymes to digest them. Image via Rapha Wilde/ Unsplash.

How did they become carnivorous?

Let’s not forget that, in the end, these carnivorous plants are still plants. So, yes, they do go through a normal photosynthesis process, which converts light into chemical energy. This process requires not only sunlight, but also water, carbon dioxide, and nutrients such as nitrogen. But carnivorous plants usually live in swampy places, such as bogs and wetlands, areas that have little nitrogen and an acidic pH. That’s why they evolved into carnivores.

Plants get nutrients from the soil through their roots. But if the soil quality isn’t good enough, with areas low in nitrogen, then the carnivorous plants need to supplement nitrogen by eating insects or animals.

But trapping and digesting prey require energy, which leaves less energy for photosynthesis. Consequently, carnivorous plants photosynthesize at significantly lower rates than regular plants. Still, these plants need ample sunlight.

Curious things about them

Most carnivorous plants respect pollinating insects. Like many other plants, carnivorous plants need pollinators, though some carnivorous plants can self-pollinate. If carnivorous plants feed on insects, how do they differentiate pollinators from non-pollinators? That’s where the magic of nature comes in to play.

Logically, the plants don’t know which insect is approaching. So, they grow a very long stem, far away from their traps, and right at the top, there is an attractive flower for the beloved pollinators.

Many carnivorous plants avoid trapping the much appreciated pollinators with a flower that is far away from their traps. Image via Juliana Barquero/ Unsplash.

Some even hibernate

Some carnivorous plants of tropical origin hibernate during winter. Although their behavior varies depending on the species, they usually shed their leaves to sprout again with the arrival of spring. This is a protective mechanism that enables the plant to survive in various climates. So, if you have one and it stops growing in winter, now you know why.

There are some species that live submerged in water. In this case, the base of the plant is submerged while the stems with traps are on the surface. How cool! This is how they feed.

Can you grow them at home?

Although they are wild plants, if you replicate the conditions in which they live, they can be grown at home. Study the type of plant and its needs before purchasing one. These plants are delicate and require specific care. You should know that some carnivorous plants survive well in cold climates, but the vast majority live in tropical and humid climates.

The soil for carnivorous plants should have few nutrients and not be fertilized. Make sure the plant has enough humidity and plenty of sunlight. If you live in a cold place, it is advisable to keep the plant indoors and create a small greenhouse to maintain humidity and warmth.

Instead of watering it from the top, place a deep container of water under the pot and let it absorb water. When the surface of the pot is wet, you can remove the container. Use distilled water or rainwater to avoid any additives found in tap water.

The plant’s feeding habits depend on the type of plant. Keep in mind that some species ONLY need sunlight and water to live.

When the plant moves, like when closing its mouths, it uses a lot of energy. So don’t play with your plant to make it close its mouths on purpose, it will lose a lot of energy and won’t receive any nutrients. It needs that energy to survive.

In many cases, you won’t have to feed it because the plant has its own system for attracting insects. If your plant is indoors and doesn’t have access to any insects, you can feed it, but take into account that it may take up to two weeks for your plant to digest the insect you offer it.

Read more: Water lilies, beautiful and colorful: Lifeform of the week

Bottom line: Beware of carnivorous plants! There are hundreds of species and they are deadly, but mostly to insects. The structure of their traps is foolproof.

The post Carnivorous plants are our lifeform of the week first appeared on EarthSky.

from EarthSky https://ift.tt/oXzjvwr