Supermassive black hole at our galaxy’s center may have a friend

An artist’s conception of two black holes entwined in a gravitational tango. Image via NASA/ JPL-Caltech/ SwRI/ MSSS/ Christopher Go.

By Smadar Naoz, University of California, Los Angeles

Do supermassive black holes have friends? The nature of galaxy formation suggests that the answer is yes, and in fact, pairs of supermassive black holes should be common in the universe.

I am an astrophysicist and am interested in a wide range of theoretical problems in astrophysics, from the formation of the very first galaxies to the gravitational interactions of black holes, stars and even planets. Black holes are intriguing systems, and supermassive black holes and the dense stellar environments that surround them represent one of the most extreme places in our universe.

The supermassive black hole that lurks at the center of our galaxy, called Sgr A*, has a mass of about 4 million times that of our sun. A black hole is a place in space where gravity is so strong that neither particles or light can escape from it. Surrounding Sgr A* is a dense cluster of stars. Precise measurements of the orbits of these stars allowed astronomers to confirm the existence of this supermassive black hole and to measure its mass. For more than 20 years, scientists have been monitoring the orbits of these stars around the supermassive black hole. Based on what we’ve seen, my colleagues and I show that if there is a friend there, it might be a second black hole nearby that is at least 100,000 times the mass of the sun.

At the center of our galaxy is a supermassive black hole in the region known as Sagittarius A. It has a mass of about 4 million times that of our sun. Image via ESA–C. Carreau.

Supermassive black holes and their friends

Almost every galaxy, including our Milky Way, has a supermassive black hole at its heart, with masses of millions to billions of times the mass of the sun. Astronomers are still studying why the heart of galaxies often hosts a supermassive black hole. One popular idea connects to the possibility that supermassive holes have friends.

To understand this idea, we need to go back to when the universe was about 100 million years old, to the era of the very first galaxies. They were much smaller than today’s galaxies, about 10,000 or more times less massive than the Milky Way. Within these early galaxies the very first stars that died created black holes, of about tens to thousand the mass of the sun. These black holes sank to the center of gravity, the heart of their host galaxy. Since galaxies evolve by merging and colliding with one another, collisions between galaxies will result in supermassive black hole pairs – the key part of this story. The black holes then collide and grow in size as well. A black hole that is more than a million times the mass of our sun is considered supermassive.

If indeed the supermassive black hole has a friend revolving around it in close orbit, the center of the galaxy is locked in a complex dance. The partners’ gravitational tugs will also exert its own pull on the nearby stars disturbing their orbits. The two supermassive black holes are orbiting each other, and at the same time, each is exerting its own pull on the stars around it.

The gravitational forces from the black holes pull on these stars and make them change their orbit; in other words, after one revolution around the supermassive black hole pair, a star will not go exactly back to the point at which it began.

Using our understanding of the gravitational interaction between the possible supermassive black hole pair and the surrounding stars, astronomers can predict what will happen to stars. Astrophysicists like my colleagues and me can compare our predictions to observations, and then can determine the possible orbits of stars and figure out whether the supermassive black hole has a companion that is exerting gravitational influence.

Using a well-studied star, called S0-2, which orbits the supermassive black hole that lies at the center of the galaxy every 16 years, we can already rule out the idea that there is a second supermassive black hole with mass above 100,000 times the mass of the sun and farther than about 200 times the distance between the sun and the Earth. If there was such a companion, then I and my colleagues would have detected its effects on the orbit of SO-2.

But that doesn’t mean that a smaller companion black hole cannot still hide there. Such an object may not alter the orbit of SO-2 in a way we can easily measure.

The physics of supermassive black holes

Supermassive black holes have gotten a lot of attention lately. In particular, the recent image of such a giant at the center of the galaxy M87 opened a new window to understanding the physics behind black holes.

The first image of a black hole. This is the supermassive black hole at the center of the galaxy M87. Image via Event Horizon Telescope Collaboration

The proximity of the Milky Way’s galactic center – a mere 24,000 light-years away – provides a unique laboratory for addressing issues in the fundamental physics of supermassive black holes. For example, astrophysicists like myself would like to understand their impact on the central regions of galaxies and their role in galaxy formation and evolution. The detection of a pair of supermassive black holes in the galactic center would indicate that the Milky Way merged with another, possibly small, galaxy at some time in the past.

That’s not all that monitoring the surrounding stars can tell us. Measurements of the star S0-2 allowed scientists to carry out a unique test of Einstein’s general theory of relativity. In May 2018, S0-2 zoomed past the supermassive black hole at a distance of only about 130 times the Earth’s distance from the sun. According to Einstein’s theory, the wavelength of light emitted by the star should stretch as it climbs from the deep gravitational well of the supermassive black hole.

The stretching wavelength that Einstein predicted – which makes the star appear redder – was detected and proves that the theory of general relativity accurately describes the physics in this extreme gravitational zone. I am eagerly awaiting the second closest approach of S0-2, which will occur in about 16 years, because astrophysicists like myself will be able to test more of Einstein’s predictions about general relativity, including the change of the orientation of the stars’ elongated orbit. But if the supermassive black hole has a partner, this could alter the expected result.

This NASA/ESA Hubble Space Telescope image show’s the result of a galactic collision between two good-sized galaxies. This new jumble of stars is slowly evolving to become a giant elliptical galaxy. Image via ESA/ Hubble/ NASA/ Acknowledgement: Judy Schmidt

Finally, if there are two massive black holes orbiting each other at the galactic center, as my team suggests is possible, they will emit gravitational waves. Since 2015, the LIGO-Virgo observatories have been detecting gravitational wave radiation from merging stellar-mass black holes and neutron stars. These groundbreaking detections have opened a new way for scientists to sense the universe.

Any waves emitted by our hypothetical black hole pair will be at low frequencies, too low for the LIGO-Virgo detectors to sense. But a planned space-based detector known as LISA may be able to detect these waves which will help astrophysicists figure out whether our galactic center black hole is alone or has a partner.

Smadar Naoz, Associate Professor of Physics & Astronomy, University of California, Los Angeles

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

Bottom line: Measurements of star orbits near the massive black hole in the center of the Milky Way galaxy suggest that there may be a second companion black hole nearby.

from EarthSky https://ift.tt/2Ekwuj8

An artist’s conception of two black holes entwined in a gravitational tango. Image via NASA/ JPL-Caltech/ SwRI/ MSSS/ Christopher Go.

By Smadar Naoz, University of California, Los Angeles

Do supermassive black holes have friends? The nature of galaxy formation suggests that the answer is yes, and in fact, pairs of supermassive black holes should be common in the universe.

I am an astrophysicist and am interested in a wide range of theoretical problems in astrophysics, from the formation of the very first galaxies to the gravitational interactions of black holes, stars and even planets. Black holes are intriguing systems, and supermassive black holes and the dense stellar environments that surround them represent one of the most extreme places in our universe.

The supermassive black hole that lurks at the center of our galaxy, called Sgr A*, has a mass of about 4 million times that of our sun. A black hole is a place in space where gravity is so strong that neither particles or light can escape from it. Surrounding Sgr A* is a dense cluster of stars. Precise measurements of the orbits of these stars allowed astronomers to confirm the existence of this supermassive black hole and to measure its mass. For more than 20 years, scientists have been monitoring the orbits of these stars around the supermassive black hole. Based on what we’ve seen, my colleagues and I show that if there is a friend there, it might be a second black hole nearby that is at least 100,000 times the mass of the sun.

At the center of our galaxy is a supermassive black hole in the region known as Sagittarius A. It has a mass of about 4 million times that of our sun. Image via ESA–C. Carreau.

Supermassive black holes and their friends

Almost every galaxy, including our Milky Way, has a supermassive black hole at its heart, with masses of millions to billions of times the mass of the sun. Astronomers are still studying why the heart of galaxies often hosts a supermassive black hole. One popular idea connects to the possibility that supermassive holes have friends.

To understand this idea, we need to go back to when the universe was about 100 million years old, to the era of the very first galaxies. They were much smaller than today’s galaxies, about 10,000 or more times less massive than the Milky Way. Within these early galaxies the very first stars that died created black holes, of about tens to thousand the mass of the sun. These black holes sank to the center of gravity, the heart of their host galaxy. Since galaxies evolve by merging and colliding with one another, collisions between galaxies will result in supermassive black hole pairs – the key part of this story. The black holes then collide and grow in size as well. A black hole that is more than a million times the mass of our sun is considered supermassive.

If indeed the supermassive black hole has a friend revolving around it in close orbit, the center of the galaxy is locked in a complex dance. The partners’ gravitational tugs will also exert its own pull on the nearby stars disturbing their orbits. The two supermassive black holes are orbiting each other, and at the same time, each is exerting its own pull on the stars around it.

The gravitational forces from the black holes pull on these stars and make them change their orbit; in other words, after one revolution around the supermassive black hole pair, a star will not go exactly back to the point at which it began.

Using our understanding of the gravitational interaction between the possible supermassive black hole pair and the surrounding stars, astronomers can predict what will happen to stars. Astrophysicists like my colleagues and me can compare our predictions to observations, and then can determine the possible orbits of stars and figure out whether the supermassive black hole has a companion that is exerting gravitational influence.

Using a well-studied star, called S0-2, which orbits the supermassive black hole that lies at the center of the galaxy every 16 years, we can already rule out the idea that there is a second supermassive black hole with mass above 100,000 times the mass of the sun and farther than about 200 times the distance between the sun and the Earth. If there was such a companion, then I and my colleagues would have detected its effects on the orbit of SO-2.

But that doesn’t mean that a smaller companion black hole cannot still hide there. Such an object may not alter the orbit of SO-2 in a way we can easily measure.

The physics of supermassive black holes

Supermassive black holes have gotten a lot of attention lately. In particular, the recent image of such a giant at the center of the galaxy M87 opened a new window to understanding the physics behind black holes.

The first image of a black hole. This is the supermassive black hole at the center of the galaxy M87. Image via Event Horizon Telescope Collaboration

The proximity of the Milky Way’s galactic center – a mere 24,000 light-years away – provides a unique laboratory for addressing issues in the fundamental physics of supermassive black holes. For example, astrophysicists like myself would like to understand their impact on the central regions of galaxies and their role in galaxy formation and evolution. The detection of a pair of supermassive black holes in the galactic center would indicate that the Milky Way merged with another, possibly small, galaxy at some time in the past.

That’s not all that monitoring the surrounding stars can tell us. Measurements of the star S0-2 allowed scientists to carry out a unique test of Einstein’s general theory of relativity. In May 2018, S0-2 zoomed past the supermassive black hole at a distance of only about 130 times the Earth’s distance from the sun. According to Einstein’s theory, the wavelength of light emitted by the star should stretch as it climbs from the deep gravitational well of the supermassive black hole.

The stretching wavelength that Einstein predicted – which makes the star appear redder – was detected and proves that the theory of general relativity accurately describes the physics in this extreme gravitational zone. I am eagerly awaiting the second closest approach of S0-2, which will occur in about 16 years, because astrophysicists like myself will be able to test more of Einstein’s predictions about general relativity, including the change of the orientation of the stars’ elongated orbit. But if the supermassive black hole has a partner, this could alter the expected result.

This NASA/ESA Hubble Space Telescope image show’s the result of a galactic collision between two good-sized galaxies. This new jumble of stars is slowly evolving to become a giant elliptical galaxy. Image via ESA/ Hubble/ NASA/ Acknowledgement: Judy Schmidt

Finally, if there are two massive black holes orbiting each other at the galactic center, as my team suggests is possible, they will emit gravitational waves. Since 2015, the LIGO-Virgo observatories have been detecting gravitational wave radiation from merging stellar-mass black holes and neutron stars. These groundbreaking detections have opened a new way for scientists to sense the universe.

Any waves emitted by our hypothetical black hole pair will be at low frequencies, too low for the LIGO-Virgo detectors to sense. But a planned space-based detector known as LISA may be able to detect these waves which will help astrophysicists figure out whether our galactic center black hole is alone or has a partner.

Smadar Naoz, Associate Professor of Physics & Astronomy, University of California, Los Angeles

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

Bottom line: Measurements of star orbits near the massive black hole in the center of the Milky Way galaxy suggest that there may be a second companion black hole nearby.

from EarthSky https://ift.tt/2Ekwuj8

All you need to know: December solstice

View larger. | Ian Hennes in Medicine Hat, Alberta, Canada, created this solargraphy between a June solstice and a December solstice. It shows the path of the sun during that time period.

Late dawn. Early sunset. Short day. Long night. For us in the Northern Hemisphere, the December solstice marks the longest night and shortest day of the year. Meanwhile, on the day of the December solstice, the Southern Hemisphere has its longest day and shortest night. The 2019 December solstice takes place on Sunday, December 22 at 4:19 UTC (That’s December 21 at 10:19 p.m. CST; translate UTC to your time).

No matter where you live on Earth’s globe, a solstice is your signal to celebrate.

EarthSky lunar calendars are cool! They make great gifts. Order now. Going fast!

Sunlight on Earth, at the December solstice. North Pole in 24-hour darkness; South Pole in 24-hour daylight. Gif via Wikimedia Commons.

When is the solstice? The solstice happens at the same instant for all of us, everywhere on Earth. In 2019, the December solstice comes on December 21 at 10:19 p.m. CST. That’s on December 22 at 4:19 Universal Time. It’s when the sun on our sky’s dome reaches its farthest southward point for the year. At this solstice, the Northern Hemisphere has its shortest day and longest night of the year.

To find the time in your location, you have to translate to your time zone. Click here to translate Universal Time to your local time.

Just remember: you’re translating from 4:19 UT on December 22. For example, if you live in Perth, Australia, you need to add 8 hours to Universal Time to find out that the solstice happens on Sunday, December 22, at 12:19 p.m. AWST (Australian Western Standard Time).

Day and night sides of Earth at the instant of the December 2019 solstice (December 22, 2019, at 4:19 UTC). Image via EarthView.

What is a solstice? The earliest people on Earth knew that the sun’s path across the sky, the length of daylight, and the location of the sunrise and sunset all shifted in a regular way throughout the year. They built monuments such as Stonehenge in England – or, for example, at Machu Picchu in Peru – to follow the sun’s yearly progress.

But we today see the solstice differently. We can picture it from the vantage point of space. Today, we know that the solstice is an astronomical event, caused by Earth’s tilt on its axis and its motion in orbit around the sun.

Because Earth doesn’t orbit upright, but is instead tilted on its axis by 23 1/2 degrees, Earth’s Northern and Southern Hemispheres trade places in receiving the sun’s light and warmth most directly. The tilt of the Earth – not our distance from the sun – is what causes winter and summer. At the December solstice, the Northern Hemisphere is leaning most away from the sun for the year.

At the December solstice, Earth is positioned in its orbit so that the sun stays below the North Pole horizon. As seen from 23 1/2 degrees south of the equator, at the imaginary line encircling the globe known as the Tropic of Capricorn, the sun shines directly overhead at noon. This is as far south as the sun ever gets. All locations south of the equator have day lengths greater than 12 hours at the December solstice. Meanwhile, all locations north of the equator have day lengths less than 12 hours.

For us on the northern part of Earth, the shortest day comes at the solstice. After the winter solstice, the days get longer, and the nights shorter. It’s a seasonal shift that nearly everyone notices.

Earth has seasons because our world is tilted on its axis with respect to our orbit around the sun. Image via NASA.

Where should I look to see signs of the solstice in nature? Everywhere.

For all of Earth’s creatures, nothing is so fundamental as the length of daylight. After all, the sun is the ultimate source of all light and warmth on Earth.

If you live in the Northern Hemisphere, you can notice the late dawns and early sunsets, and the low arc of the sun across the sky each day. You might notice how low the sun appears in the sky at local noon. And be sure to look at your noontime shadow. Around the time of the December solstice, it’s your longest noontime shadow of the year.

In the Southern Hemisphere, it’s opposite. Dawn comes early, and dusk comes late. The sun is high. It’s your shortest noontime shadow of the year.

Around the time of the winter solstice, watch for late dawns, early sunsets, and the low arc of the sun across the sky each day. Notice your noontime shadow, the longest of the year. Photo via Serge Arsenie on Flickr.

Meanwhile, at the summer solstice, noontime shadows are short. Photo via the Slam Summer Beach Volleyball festival in Australia.

Why doesn’t the earliest sunset come on the shortest day? The December solstice marks the shortest day of the year in the Northern Hemisphere and longest day in the Southern Hemisphere. But the earliest sunset – or earliest sunrise if you’re south of the equator – happens before the December solstice. Many people notice this, and ask about it.

The key to understanding the earliest sunset is not to focus on the time of sunset or sunrise. The key is to focus on what is called true solar noon – the time of day that the sun reaches its highest point in its journey across your sky.

In early December, true solar noon comes nearly 10 minutes earlier by the clock than it does at the solstice around December 22. With true noon coming later on the solstice, so will the sunrise and sunset times.

It’s this discrepancy between clock time and sun time that causes the Northern Hemisphere’s earliest sunset and the Southern Hemisphere’s earliest sunrise to precede the December solstice.

The discrepancy occurs primarily because of the tilt of the Earth’s axis. A secondary but another contributing factor to this discrepancy between clock noon and sun noon comes from the Earth’s elliptical – oblong – orbit around the sun. The Earth’s orbit is not a perfect circle, and when we’re closest to the sun, our world moves fastest in orbit. Our closest point to the sun – or perihelion – comes in early January. So we are moving fastest in orbit around now, slightly faster than our average speed of about 18.5 miles per second (30 kilometers per second). The discrepancy between sun time and clock time is greater around the December solstice than the June solstice because we’re nearer the sun at this time of year.

Solstice sunsets, showing the sun’s position on the local horizon at December 2015 (left) and June 2016 (right) solstices from Mutare, Zimbabwe via Peter Lowenstein.

The precise date of the earliest sunset depends on your latitude. At mid-northern latitudes, it comes in early December each year. At northern temperate latitudes farther north – such as in Canada and Alaska – the year’s earliest sunset comes around mid-December. Close to the Arctic Circle, the earliest sunset and the December solstice occur on or near the same day.

By the way, the latest sunrise doesn’t come on the solstice either. From mid-northern latitudes, the latest sunrise comes in early January.

The exact dates vary, but the sequence is always the same: earliest sunset in early December, shortest day on the solstice around December 22, latest sunrise in early January.

And so the cycle continues.

Solstice Pyrotechnics II by groovehouse on Flickr.

Bottom line: In 2018, the December solstice comes on December 21 at 4:23 p.m. CST. That’s December 21 at 22:23 UTC. It marks the Northern Hemisphere’s shortest day (first day of winter) and Southern Hemisphere’s longest day (first day of summer). Happy solstice, everyone!

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from EarthSky https://ift.tt/2A1j7Tk

View larger. | Ian Hennes in Medicine Hat, Alberta, Canada, created this solargraphy between a June solstice and a December solstice. It shows the path of the sun during that time period.

Late dawn. Early sunset. Short day. Long night. For us in the Northern Hemisphere, the December solstice marks the longest night and shortest day of the year. Meanwhile, on the day of the December solstice, the Southern Hemisphere has its longest day and shortest night. The 2019 December solstice takes place on Sunday, December 22 at 4:19 UTC (That’s December 21 at 10:19 p.m. CST; translate UTC to your time).

No matter where you live on Earth’s globe, a solstice is your signal to celebrate.

EarthSky lunar calendars are cool! They make great gifts. Order now. Going fast!

Sunlight on Earth, at the December solstice. North Pole in 24-hour darkness; South Pole in 24-hour daylight. Gif via Wikimedia Commons.

When is the solstice? The solstice happens at the same instant for all of us, everywhere on Earth. In 2019, the December solstice comes on December 21 at 10:19 p.m. CST. That’s on December 22 at 4:19 Universal Time. It’s when the sun on our sky’s dome reaches its farthest southward point for the year. At this solstice, the Northern Hemisphere has its shortest day and longest night of the year.

To find the time in your location, you have to translate to your time zone. Click here to translate Universal Time to your local time.

Just remember: you’re translating from 4:19 UT on December 22. For example, if you live in Perth, Australia, you need to add 8 hours to Universal Time to find out that the solstice happens on Sunday, December 22, at 12:19 p.m. AWST (Australian Western Standard Time).

Day and night sides of Earth at the instant of the December 2019 solstice (December 22, 2019, at 4:19 UTC). Image via EarthView.

What is a solstice? The earliest people on Earth knew that the sun’s path across the sky, the length of daylight, and the location of the sunrise and sunset all shifted in a regular way throughout the year. They built monuments such as Stonehenge in England – or, for example, at Machu Picchu in Peru – to follow the sun’s yearly progress.

But we today see the solstice differently. We can picture it from the vantage point of space. Today, we know that the solstice is an astronomical event, caused by Earth’s tilt on its axis and its motion in orbit around the sun.

Because Earth doesn’t orbit upright, but is instead tilted on its axis by 23 1/2 degrees, Earth’s Northern and Southern Hemispheres trade places in receiving the sun’s light and warmth most directly. The tilt of the Earth – not our distance from the sun – is what causes winter and summer. At the December solstice, the Northern Hemisphere is leaning most away from the sun for the year.

At the December solstice, Earth is positioned in its orbit so that the sun stays below the North Pole horizon. As seen from 23 1/2 degrees south of the equator, at the imaginary line encircling the globe known as the Tropic of Capricorn, the sun shines directly overhead at noon. This is as far south as the sun ever gets. All locations south of the equator have day lengths greater than 12 hours at the December solstice. Meanwhile, all locations north of the equator have day lengths less than 12 hours.

For us on the northern part of Earth, the shortest day comes at the solstice. After the winter solstice, the days get longer, and the nights shorter. It’s a seasonal shift that nearly everyone notices.

Earth has seasons because our world is tilted on its axis with respect to our orbit around the sun. Image via NASA.

Where should I look to see signs of the solstice in nature? Everywhere.

For all of Earth’s creatures, nothing is so fundamental as the length of daylight. After all, the sun is the ultimate source of all light and warmth on Earth.

If you live in the Northern Hemisphere, you can notice the late dawns and early sunsets, and the low arc of the sun across the sky each day. You might notice how low the sun appears in the sky at local noon. And be sure to look at your noontime shadow. Around the time of the December solstice, it’s your longest noontime shadow of the year.

In the Southern Hemisphere, it’s opposite. Dawn comes early, and dusk comes late. The sun is high. It’s your shortest noontime shadow of the year.

Around the time of the winter solstice, watch for late dawns, early sunsets, and the low arc of the sun across the sky each day. Notice your noontime shadow, the longest of the year. Photo via Serge Arsenie on Flickr.

Meanwhile, at the summer solstice, noontime shadows are short. Photo via the Slam Summer Beach Volleyball festival in Australia.

Why doesn’t the earliest sunset come on the shortest day? The December solstice marks the shortest day of the year in the Northern Hemisphere and longest day in the Southern Hemisphere. But the earliest sunset – or earliest sunrise if you’re south of the equator – happens before the December solstice. Many people notice this, and ask about it.

The key to understanding the earliest sunset is not to focus on the time of sunset or sunrise. The key is to focus on what is called true solar noon – the time of day that the sun reaches its highest point in its journey across your sky.

In early December, true solar noon comes nearly 10 minutes earlier by the clock than it does at the solstice around December 22. With true noon coming later on the solstice, so will the sunrise and sunset times.

It’s this discrepancy between clock time and sun time that causes the Northern Hemisphere’s earliest sunset and the Southern Hemisphere’s earliest sunrise to precede the December solstice.

The discrepancy occurs primarily because of the tilt of the Earth’s axis. A secondary but another contributing factor to this discrepancy between clock noon and sun noon comes from the Earth’s elliptical – oblong – orbit around the sun. The Earth’s orbit is not a perfect circle, and when we’re closest to the sun, our world moves fastest in orbit. Our closest point to the sun – or perihelion – comes in early January. So we are moving fastest in orbit around now, slightly faster than our average speed of about 18.5 miles per second (30 kilometers per second). The discrepancy between sun time and clock time is greater around the December solstice than the June solstice because we’re nearer the sun at this time of year.

Solstice sunsets, showing the sun’s position on the local horizon at December 2015 (left) and June 2016 (right) solstices from Mutare, Zimbabwe via Peter Lowenstein.

The precise date of the earliest sunset depends on your latitude. At mid-northern latitudes, it comes in early December each year. At northern temperate latitudes farther north – such as in Canada and Alaska – the year’s earliest sunset comes around mid-December. Close to the Arctic Circle, the earliest sunset and the December solstice occur on or near the same day.

By the way, the latest sunrise doesn’t come on the solstice either. From mid-northern latitudes, the latest sunrise comes in early January.

The exact dates vary, but the sequence is always the same: earliest sunset in early December, shortest day on the solstice around December 22, latest sunrise in early January.

And so the cycle continues.

Solstice Pyrotechnics II by groovehouse on Flickr.

Bottom line: In 2018, the December solstice comes on December 21 at 4:23 p.m. CST. That’s December 21 at 22:23 UTC. It marks the Northern Hemisphere’s shortest day (first day of winter) and Southern Hemisphere’s longest day (first day of summer). Happy solstice, everyone!

Want to see 2018’s brightest comet? How to see comet 46P/Wirtanen

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See a celestial Chariot in December

Tonight, or any one of these long December nights, you can find the constellation Auriga the Charioteer. The Heavenly Chariot – with its brilliant yellow star Capella – starts the journey in the northeast at early evening, flies overhead around midnight and finishes up in the northwest at dawn.

Our chart shows Auriga at the vicinity of midnight, when this pentagon-shaped pattern hits the zenith, or highest point in the sky. From the Northern Hemisphere, however, you can actually see Capella and the Celestial Chariot in the northeast sky at nightfall.

EarthSky’s lunar calendar is the perfect gift for any sky lover! Order now – they’re going fast!

Sky chart of the constellation Auriga the Charioteer

The constellation Auriga. The ecliptic and galactic equator intersect near the June solstice point. Click here for a larger chart.

As seen from either the Northern or Southern Hemisphere, the constellations Auriga and Orion always climb highest for the night in concert. If you live at middle and far northern latitudes, you’ll see Auriga above Orion. If you live in the Southern Hemisphere, you’ll see Auriga below Orion. Either way, Auriga shines to the north of Orion the Giant Hunter.

There are several easy-to-find and famous star clusters in Auriga. With binoculars, you might be able to spot them. They’re known by their “M” numbers – named for the famous astronomer Charles Messier – M36, M37 and M38. To the south of these star clusters, also close to the galactic equator, look for M35 in the constellation Gemini the Twins, at the foot of Castor, the mortal twin.

Now turn your focus to Capella, the brightest star in Auriga. According to star lore, Capella represents Amalthea, the she-goat that fed the infant Zeus when he was hidden away in a cave on Mt. Ida in Crete. This was during the war between the Olympian and the Titan gods. Of course, the river of milk that spilled from Amalthea the she-goat formed the Milky Way!

Auriga’s stars Menkalinan and Theta Aurigae (see above sky charts) run north to south. They point northward to Polaris, the North Star, and south to Orion’s bright ruddy star Betelgeuse. With binoculars, check out the star cluster M35 between Theta Aurigae and Betelgeuse.

Bottom line: On these long December nights, you can find the constellation Auriga the Charioteer. There are several easy-to-find and very famous star clusters in Auriga.

Want to see 2018’s brightest comet? How to see comet 46P/Wirtanen

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Tonight, or any one of these long December nights, you can find the constellation Auriga the Charioteer. The Heavenly Chariot – with its brilliant yellow star Capella – starts the journey in the northeast at early evening, flies overhead around midnight and finishes up in the northwest at dawn.

Our chart shows Auriga at the vicinity of midnight, when this pentagon-shaped pattern hits the zenith, or highest point in the sky. From the Northern Hemisphere, however, you can actually see Capella and the Celestial Chariot in the northeast sky at nightfall.

EarthSky’s lunar calendar is the perfect gift for any sky lover! Order now – they’re going fast!

Sky chart of the constellation Auriga the Charioteer

The constellation Auriga. The ecliptic and galactic equator intersect near the June solstice point. Click here for a larger chart.

As seen from either the Northern or Southern Hemisphere, the constellations Auriga and Orion always climb highest for the night in concert. If you live at middle and far northern latitudes, you’ll see Auriga above Orion. If you live in the Southern Hemisphere, you’ll see Auriga below Orion. Either way, Auriga shines to the north of Orion the Giant Hunter.

There are several easy-to-find and famous star clusters in Auriga. With binoculars, you might be able to spot them. They’re known by their “M” numbers – named for the famous astronomer Charles Messier – M36, M37 and M38. To the south of these star clusters, also close to the galactic equator, look for M35 in the constellation Gemini the Twins, at the foot of Castor, the mortal twin.

Now turn your focus to Capella, the brightest star in Auriga. According to star lore, Capella represents Amalthea, the she-goat that fed the infant Zeus when he was hidden away in a cave on Mt. Ida in Crete. This was during the war between the Olympian and the Titan gods. Of course, the river of milk that spilled from Amalthea the she-goat formed the Milky Way!

Auriga’s stars Menkalinan and Theta Aurigae (see above sky charts) run north to south. They point northward to Polaris, the North Star, and south to Orion’s bright ruddy star Betelgeuse. With binoculars, check out the star cluster M35 between Theta Aurigae and Betelgeuse.

Bottom line: On these long December nights, you can find the constellation Auriga the Charioteer. There are several easy-to-find and very famous star clusters in Auriga.

Want to see 2018’s brightest comet? How to see comet 46P/Wirtanen

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Middle of eclipse season December 30

Various stages of an annular solar eclipse from Brocken Inaglory via Wikimedia Commons.

The upcoming annual solar eclipse on December 26, 2019, happens some 4 days before the middle of the eclipse season, which falls on December 30, 2019. An eclipse season lasts for about 35 days, and any new moon or full moon occurring within this time period will undergo an eclipse. Given that the lunar month (period of time between successive new moons or successive full moons) is about 29.5 days long, a minimum of 2 eclipses (one solar and one lunar, in either order), or a maximum of 3 eclipses (either lunar/solar/lunar, or solar/lunar/solar) can take place in one eclipse season.

Most often, there are only two eclipses in one eclipse season. For three eclipses to occur, the first one has to come quite early in the eclipse season to allow for a third eclipse near the end.

Eclipses are all about alignments. In a solar eclipse, the sun, moon and Earth line up, with the moon in the middle. Image via NASA.

In a lunar eclipse, the sun, Earth and moon line up, with the Earth in the middle. Image via NASA.

This time around, there are 2 eclipses in one eclipse season. The solar eclipse on December 26, 2019, happens about 4 days before the middle of the eclipse season, whereas the lunar eclipse on January 10, 2020, comes a solid 11 days after the midpoint of the eclipse season. Because this lunar eclipse happens rather late in the eclipse season, the upcoming new moon on January 10, 2020, won’t even meet up with the Earth’s dark umbral shadow. Rather, it’ll be a penumbral eclipse of the moon, whereby the moon sweeps through the faint penumbral shadow but misses the dark umbra, as depicted on the diagram below.

On January 10, 2020, the new moon misses the dark umbral shadow but goes through the faint penumbra, to present a barely perceptible eclipse. This eclipse would be more impressive from the moon, where you’d see a partial eclipse of the the sun.

However, if an eclipse happens fairly close to the mid-point of the eclipse season, as does the annular solar eclipse on December 26, 2019, then you have a central eclipse. If it’s a solar eclipse, the central eclipse presents either a total or annular eclipse of the sun; or if it’s a lunar eclipse, the central eclipse features a total eclipse of the moon. If the eclipse falls near the beginning or the end of the eclipse season, it’s either a penumbral eclipse of the moon or small partial eclipse of the sun.

Eclipses of the new moon and full moon don’t occur every month. That’s because the moon’s orbital plane is inclined by about 5 degrees to the plane of the ecliptic (Earth’s orbital plane). But the moon’s orbital path does intersect the Earth’s orbital plane at two points called nodes. Whenever these lunar nodes point directly at the sun, it marks the midpoint of the eclipse season. The lunar nodes line up with the sun in periods of about 173.3 days, or nearly 10 days shy of six calendar months. Therefore, the middle of the eclipse season will next recur around the June 2020 solstice, when the line of nodes once again points directly at the sun.

Whenever the lunar nodes point directly at the sun, it marks the midpoint of the approximate 35-day eclipse season. The middle of the eclipse season occurs on December 30, 2019, and then again on June 20, 2020. Image via Go Science GO.

Because the lunar eclipses will happen so early and so late in the June/July 2020 eclipse season, the lunar eclipses on June 5, 2020, and July 5, 2020, will be extremely faint and hard-to-see penumbral lunar eclipses. See the illustration of these eclipses below.

The next eclipse season in June/July 2020 will showcase three eclipses (lunar/solar/lunar). Image via Wikipedia.

On the other hand, the solar eclipse on June 21, 2020, which takes place almost dead center in the eclipse season, will present a central eclipse, exhibiting an annular eclipse of the sun. See above.

Thirty-eight eclipse seasons (19 eclipse years) are almost exactly commensurate to 223 lunar months, a period of 18 years and 11 1/3 days (4 intervening leaps years) or 18 years and 10 1/3 days (5 intervening leap years). Therefore, the eclipses coming up in June/July 2038 display similar geometries to those in June/July 2020. This 223-lunar-month period of time is known as the Saros.

The year 2020:

June 05, 2020: Penumbral lunar eclipse
June 21, 2020: Annular solar eclipse
July 05, 2020: Penumbral lunar eclipse

The year 2038:

June 17, 2038: Penumbral lunar eclipse
July 02, 2038: Annular solar eclipse
July 16, 2038: Penumbral lunar eclipse

Interestingly, the Sar or Half Saros, representing a period of 111.5 lunar months (9 years and 5 2/3 days), gives us alternating eclipses (solar/lunar/solar) of similar character. Contrast the years 2020 and 2038 above with the years 2029 and 2047 below.

A number of people are familiar with the Saros period of 223 lunar months (18.03 years), whereby a similar progression of eclipses takes place in one eclipse season (lunar/solar/lunar). Less well known, the Sar or Half Saros of 111.5 lunar months (9.015 years) also presents 3 eclipses in one eclipse season, though in alternate order (solar/lunar/solar). Image via Wikipedia.

The year 2029:

June 12, 2029: Partial solar eclipse
June 26, 2029: Total lunar eclipse
July 11, 2029; Partial solar eclipse

The year 2047:

June 23, 2047: Partial solar eclipse
July 07, 2047: Total lunar eclipse
July 22, 2047: Partial solar eclipse

The eclipse master Feed Espenak tells us a Saros series can last anywhere from 1,226 to 1,550 years and is made up of 69 to 87 eclipses. A Saros series, whether it be solar or lunar, always starts off with skimpy eclipses and ends with skimpy eclipses. The middle of a Saros series brings about the closest alignment of the three celestial bodies – Earth, sun and moon – whereby they line up almost perfectly in space.

In any eclipse season where there are 3 eclipses, the first and third eclipses are meager productions whereas the middle eclipse is a highly visible central eclipse. And in any Saros series, the early and late eclipses are also paltry at best, whereas the middle part of a Saros series presents central eclipses.

Here’s something that may surprise you: Any eclipse happening early in an eclipse season always occurs late in a Saros series – and vice versa. For example, let’s look at the upcoming three-eclipse season in June/July 2020:

The year 2020:

June 05, 2020: Penumbral lunar eclipse
June 21, 2020: Annular solar eclipse
July 05, 2020: Penumbral lunar eclipse

The first eclipse of the eclipse season on June 5, 2020, belongs to Lunar Saros 111 and presents the 67th of 71 eclipses in this Saros series. Yet, the third and final eclipse of the eclipse season on July 5, 2020, belongs to Lunar Saros 149, and features the 3rd of 71 eclipses in this particular Saros series.

Unsurprisingly, perhaps, the second (or middle) eclipse of the eclipse season on June 21, 2020, is the 36th of 70 eclipses in Solar Saros 137.

The plane of the moon’s orbit is inclined at 5 degrees to the plane of Earth’s orbit around the sun (the ecliptic). In this diagram, however, the ecliptic is portrayed as the sun’s apparent annual path in front of the constellations of the zodiac. The moon’s orbit intersects the ecliptic at two points called nodes (labeled here as N1 and N2). It’s the middle of the eclipse season whenever this line of nodes points directly at the sun. In the above diagram, the line of nodes does not point at the sun.

Bottom line: The middle of the eclipse season falls on December 30, 2019, and this eclipse season hosts two eclipses: an annular solar eclipse on December 26, 2019, and a penumbral lunar eclipse on January 10, 2020. The following eclipse season coming less than six calendar months thereafter will produce three eclipses (lunar/solar/lunar), though only the second of these three eclipses – the annular “ring of fire” eclipse on June 21, 2020 – will produce any real theatrics on the great stage of sky.

from EarthSky https://ift.tt/2Ej4Kvi

Various stages of an annular solar eclipse from Brocken Inaglory via Wikimedia Commons.

The upcoming annual solar eclipse on December 26, 2019, happens some 4 days before the middle of the eclipse season, which falls on December 30, 2019. An eclipse season lasts for about 35 days, and any new moon or full moon occurring within this time period will undergo an eclipse. Given that the lunar month (period of time between successive new moons or successive full moons) is about 29.5 days long, a minimum of 2 eclipses (one solar and one lunar, in either order), or a maximum of 3 eclipses (either lunar/solar/lunar, or solar/lunar/solar) can take place in one eclipse season.

Most often, there are only two eclipses in one eclipse season. For three eclipses to occur, the first one has to come quite early in the eclipse season to allow for a third eclipse near the end.

Eclipses are all about alignments. In a solar eclipse, the sun, moon and Earth line up, with the moon in the middle. Image via NASA.

In a lunar eclipse, the sun, Earth and moon line up, with the Earth in the middle. Image via NASA.

This time around, there are 2 eclipses in one eclipse season. The solar eclipse on December 26, 2019, happens about 4 days before the middle of the eclipse season, whereas the lunar eclipse on January 10, 2020, comes a solid 11 days after the midpoint of the eclipse season. Because this lunar eclipse happens rather late in the eclipse season, the upcoming new moon on January 10, 2020, won’t even meet up with the Earth’s dark umbral shadow. Rather, it’ll be a penumbral eclipse of the moon, whereby the moon sweeps through the faint penumbral shadow but misses the dark umbra, as depicted on the diagram below.

On January 10, 2020, the new moon misses the dark umbral shadow but goes through the faint penumbra, to present a barely perceptible eclipse. This eclipse would be more impressive from the moon, where you’d see a partial eclipse of the the sun.

However, if an eclipse happens fairly close to the mid-point of the eclipse season, as does the annular solar eclipse on December 26, 2019, then you have a central eclipse. If it’s a solar eclipse, the central eclipse presents either a total or annular eclipse of the sun; or if it’s a lunar eclipse, the central eclipse features a total eclipse of the moon. If the eclipse falls near the beginning or the end of the eclipse season, it’s either a penumbral eclipse of the moon or small partial eclipse of the sun.

Eclipses of the new moon and full moon don’t occur every month. That’s because the moon’s orbital plane is inclined by about 5 degrees to the plane of the ecliptic (Earth’s orbital plane). But the moon’s orbital path does intersect the Earth’s orbital plane at two points called nodes. Whenever these lunar nodes point directly at the sun, it marks the midpoint of the eclipse season. The lunar nodes line up with the sun in periods of about 173.3 days, or nearly 10 days shy of six calendar months. Therefore, the middle of the eclipse season will next recur around the June 2020 solstice, when the line of nodes once again points directly at the sun.

Whenever the lunar nodes point directly at the sun, it marks the midpoint of the approximate 35-day eclipse season. The middle of the eclipse season occurs on December 30, 2019, and then again on June 20, 2020. Image via Go Science GO.

Because the lunar eclipses will happen so early and so late in the June/July 2020 eclipse season, the lunar eclipses on June 5, 2020, and July 5, 2020, will be extremely faint and hard-to-see penumbral lunar eclipses. See the illustration of these eclipses below.

The next eclipse season in June/July 2020 will showcase three eclipses (lunar/solar/lunar). Image via Wikipedia.

On the other hand, the solar eclipse on June 21, 2020, which takes place almost dead center in the eclipse season, will present a central eclipse, exhibiting an annular eclipse of the sun. See above.

Thirty-eight eclipse seasons (19 eclipse years) are almost exactly commensurate to 223 lunar months, a period of 18 years and 11 1/3 days (4 intervening leaps years) or 18 years and 10 1/3 days (5 intervening leap years). Therefore, the eclipses coming up in June/July 2038 display similar geometries to those in June/July 2020. This 223-lunar-month period of time is known as the Saros.

The year 2020:

June 05, 2020: Penumbral lunar eclipse
June 21, 2020: Annular solar eclipse
July 05, 2020: Penumbral lunar eclipse

The year 2038:

June 17, 2038: Penumbral lunar eclipse
July 02, 2038: Annular solar eclipse
July 16, 2038: Penumbral lunar eclipse

Interestingly, the Sar or Half Saros, representing a period of 111.5 lunar months (9 years and 5 2/3 days), gives us alternating eclipses (solar/lunar/solar) of similar character. Contrast the years 2020 and 2038 above with the years 2029 and 2047 below.

A number of people are familiar with the Saros period of 223 lunar months (18.03 years), whereby a similar progression of eclipses takes place in one eclipse season (lunar/solar/lunar). Less well known, the Sar or Half Saros of 111.5 lunar months (9.015 years) also presents 3 eclipses in one eclipse season, though in alternate order (solar/lunar/solar). Image via Wikipedia.

The year 2029:

June 12, 2029: Partial solar eclipse
June 26, 2029: Total lunar eclipse
July 11, 2029; Partial solar eclipse

The year 2047:

June 23, 2047: Partial solar eclipse
July 07, 2047: Total lunar eclipse
July 22, 2047: Partial solar eclipse

The eclipse master Feed Espenak tells us a Saros series can last anywhere from 1,226 to 1,550 years and is made up of 69 to 87 eclipses. A Saros series, whether it be solar or lunar, always starts off with skimpy eclipses and ends with skimpy eclipses. The middle of a Saros series brings about the closest alignment of the three celestial bodies – Earth, sun and moon – whereby they line up almost perfectly in space.

In any eclipse season where there are 3 eclipses, the first and third eclipses are meager productions whereas the middle eclipse is a highly visible central eclipse. And in any Saros series, the early and late eclipses are also paltry at best, whereas the middle part of a Saros series presents central eclipses.

Here’s something that may surprise you: Any eclipse happening early in an eclipse season always occurs late in a Saros series – and vice versa. For example, let’s look at the upcoming three-eclipse season in June/July 2020:

The year 2020:

June 05, 2020: Penumbral lunar eclipse
June 21, 2020: Annular solar eclipse
July 05, 2020: Penumbral lunar eclipse

The first eclipse of the eclipse season on June 5, 2020, belongs to Lunar Saros 111 and presents the 67th of 71 eclipses in this Saros series. Yet, the third and final eclipse of the eclipse season on July 5, 2020, belongs to Lunar Saros 149, and features the 3rd of 71 eclipses in this particular Saros series.

Unsurprisingly, perhaps, the second (or middle) eclipse of the eclipse season on June 21, 2020, is the 36th of 70 eclipses in Solar Saros 137.

The plane of the moon’s orbit is inclined at 5 degrees to the plane of Earth’s orbit around the sun (the ecliptic). In this diagram, however, the ecliptic is portrayed as the sun’s apparent annual path in front of the constellations of the zodiac. The moon’s orbit intersects the ecliptic at two points called nodes (labeled here as N1 and N2). It’s the middle of the eclipse season whenever this line of nodes points directly at the sun. In the above diagram, the line of nodes does not point at the sun.

Bottom line: The middle of the eclipse season falls on December 30, 2019, and this eclipse season hosts two eclipses: an annular solar eclipse on December 26, 2019, and a penumbral lunar eclipse on January 10, 2020. The following eclipse season coming less than six calendar months thereafter will produce three eclipses (lunar/solar/lunar), though only the second of these three eclipses – the annular “ring of fire” eclipse on June 21, 2020 – will produce any real theatrics on the great stage of sky.

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Bringing community astronomy to rural Africa

Nurul Fatini Jaafar demonstrates sky software to a Semelai family in Malaysia. Image via Nurul Fatini Jaafar.

By Graham Jones

If the earth is a spaceship, we all have a window seat.

The sky is there for everyone, and the fundamentals of skywatching — from the rhythm of the moon, to the pattern of the stars — have remained unchanged throughout human history.

Yet inequalities exist. Both within the astronomy community and beyond, in the area of education and public outreach, people face barriers because of their age, ethnicity, gender, culture, ability or disability, religion, race, sexuality or a combination of these factors.

Last month, (November 2019) more than 100 members of the International Astronomical Union (IAU) gathered in Tokyo to discuss a roadmap to action. Astronomy for Equity, Diversity and Inclusion was a four-day symposium hosted by the National Astronomical Observatory of Japan; its aims were to show how diversity and inclusion produce better science and innovation, and to focus on the steps needed to achieve change.

When it comes to the challenge of communicating astronomy to communities around the world, some of the proposed solutions were to be found surprisingly close to people’s homes.

Ikechukwu Anthony Obi works for the Center for Basic Space Science at Nigeria’s National Space Research and Development Agency. He is clear about the difficulties of bringing astronomy to the poorest communities of Africa’s most populous country: problems with the supply of electricity, little or no funding, and misinformation.

At the same time, Obi is equally clear about the opportunities. He said:

Rural settings have the clearest and darkest sky. There are also no city-life distractions, and people have a sound knowledge of cultural astronomy.

Ikechukwu Anthony Obi works with budding astronomers at a school in Nigeria. (The Raspberry Pi computer is the small red device.)

Obi’s vision for community astronomy in Nigeria is based around low-cost battery-powered equipment, and virtual observatory tools. He explained:

Credit-card-sized Raspberry Pi computers can be set up in schools and used for giving hands-on experience of astronomical data analysis. We can also do astrophotography with locally made telescopes.

One particularly ingenious idea involves a piece of technology that can be seen on the roofs of dwellings across Nigeria. Obi said:

Satellite TV dishes are everywhere. Nigerians are heavy internet users and telecom consumers, and there is a booming entertainment industry. With a Raspberry Pi and a satellite finder, we can adapt these locally available satellite dishes to provide early exposure to radio astronomy.

Students and teachers alike are thrilled by the science that can be done with these set-ups. It enables them to appreciate the scientific principles underlying the already known and well-practiced cultural astronomy.

The importance of working in harmony with indigenous cultural knowledge was also the message of Nurul Fatini Jaafar, an ethno-astronomy researcher at the University of Malaya in Kuala Lumpur. She works with the Semelai people of Lake Bera, in the center of the Malaysian peninsula.

Nurul’s research involves participant observation and in-depth interviews. She said:

In a typical setting where both men and women are present, the men will always respond to my questions. The women will keep silent.

However, when only women are present, things change. Nurul, who holds a degree in physics and astronomy, said:

I was taken by surprise to learn that the women actually understand a lot about astronomy. They possess knowledge about stellar positioning, celestial forecasts and moon phases. Their comprehension of the sky is one step ahead of the typical male.

Sadly, this knowledge is not always valued. Nurual said:

Indigenous children who are enrolled in national schools — which instill the western science perspective — are unaware of the reliability of their traditional science. Their knowledge system is seen as anecdotal and unscientific, and there is a presumption that their parents have no authority towards scientific knowledge. As a result, their parents cannot guide them with science subjects at home.

Nurul is part of pilot project to involve women in science. She said:

We have started to explore astronomical topics from a cultural perspective. We are acquainting them with smartphones that are equipped with astronomical software, and are showing them the projection of the sky. We hope that the women will help us to integrate the two paradigms of western science and indigenous knowledge.

These women have always wanted a bigger role in educating their children in science. Now they are looking forward to the moment when their dreams finally materialize.

Bottom line: The IAU is working on a roadmap to better science and innovation through equity, diversity and inclusion.

from EarthSky https://ift.tt/2rBMNWd

Nurul Fatini Jaafar demonstrates sky software to a Semelai family in Malaysia. Image via Nurul Fatini Jaafar.

By Graham Jones

If the earth is a spaceship, we all have a window seat.

The sky is there for everyone, and the fundamentals of skywatching — from the rhythm of the moon, to the pattern of the stars — have remained unchanged throughout human history.

Yet inequalities exist. Both within the astronomy community and beyond, in the area of education and public outreach, people face barriers because of their age, ethnicity, gender, culture, ability or disability, religion, race, sexuality or a combination of these factors.

Last month, (November 2019) more than 100 members of the International Astronomical Union (IAU) gathered in Tokyo to discuss a roadmap to action. Astronomy for Equity, Diversity and Inclusion was a four-day symposium hosted by the National Astronomical Observatory of Japan; its aims were to show how diversity and inclusion produce better science and innovation, and to focus on the steps needed to achieve change.

When it comes to the challenge of communicating astronomy to communities around the world, some of the proposed solutions were to be found surprisingly close to people’s homes.

Ikechukwu Anthony Obi works for the Center for Basic Space Science at Nigeria’s National Space Research and Development Agency. He is clear about the difficulties of bringing astronomy to the poorest communities of Africa’s most populous country: problems with the supply of electricity, little or no funding, and misinformation.

At the same time, Obi is equally clear about the opportunities. He said:

Rural settings have the clearest and darkest sky. There are also no city-life distractions, and people have a sound knowledge of cultural astronomy.

Ikechukwu Anthony Obi works with budding astronomers at a school in Nigeria. (The Raspberry Pi computer is the small red device.)

Obi’s vision for community astronomy in Nigeria is based around low-cost battery-powered equipment, and virtual observatory tools. He explained:

Credit-card-sized Raspberry Pi computers can be set up in schools and used for giving hands-on experience of astronomical data analysis. We can also do astrophotography with locally made telescopes.

One particularly ingenious idea involves a piece of technology that can be seen on the roofs of dwellings across Nigeria. Obi said:

Satellite TV dishes are everywhere. Nigerians are heavy internet users and telecom consumers, and there is a booming entertainment industry. With a Raspberry Pi and a satellite finder, we can adapt these locally available satellite dishes to provide early exposure to radio astronomy.

Students and teachers alike are thrilled by the science that can be done with these set-ups. It enables them to appreciate the scientific principles underlying the already known and well-practiced cultural astronomy.

The importance of working in harmony with indigenous cultural knowledge was also the message of Nurul Fatini Jaafar, an ethno-astronomy researcher at the University of Malaya in Kuala Lumpur. She works with the Semelai people of Lake Bera, in the center of the Malaysian peninsula.

Nurul’s research involves participant observation and in-depth interviews. She said:

In a typical setting where both men and women are present, the men will always respond to my questions. The women will keep silent.

However, when only women are present, things change. Nurul, who holds a degree in physics and astronomy, said:

I was taken by surprise to learn that the women actually understand a lot about astronomy. They possess knowledge about stellar positioning, celestial forecasts and moon phases. Their comprehension of the sky is one step ahead of the typical male.

Sadly, this knowledge is not always valued. Nurual said:

Indigenous children who are enrolled in national schools — which instill the western science perspective — are unaware of the reliability of their traditional science. Their knowledge system is seen as anecdotal and unscientific, and there is a presumption that their parents have no authority towards scientific knowledge. As a result, their parents cannot guide them with science subjects at home.

Nurul is part of pilot project to involve women in science. She said:

We have started to explore astronomical topics from a cultural perspective. We are acquainting them with smartphones that are equipped with astronomical software, and are showing them the projection of the sky. We hope that the women will help us to integrate the two paradigms of western science and indigenous knowledge.

These women have always wanted a bigger role in educating their children in science. Now they are looking forward to the moment when their dreams finally materialize.

Bottom line: The IAU is working on a roadmap to better science and innovation through equity, diversity and inclusion.

from EarthSky https://ift.tt/2rBMNWd

News digest – NHS drug decisions, leukaemia treatment trials and long term anastrozole benefits

Focusing on a cancer cure masks progress, says charity

The Institute of Cancer Research has warned that focusing on the cure for cancer as the ‘holy grail’ of cancer research has undermined people’s understanding of how much progress has been made in the field. Researchers conducted a survey which analysed the public and patient opinion of cancer as a long-term, manageable disease. Reported in The Guardian, the results showed that only 28 out of 100 of people believe cancers can be controlled long-term despite the fact that, on average, people are living for more than 10 years after a cancer diagnosis.

Breast cancer treatment combo approved for NHS use in England

A third treatment combination has been approved for some patients with advanced breast cancer on the NHS in England, the Daily Mail reports. The treatment, which combines the targeted drug palbociclib and an injectable hormone therapy, was already an option for women who had not yet received hormone therapy but will now be available to those who have already completed this treatment. Similar drug combinations were approved for use for the same group of women earlier this year. The combination should also be available soon to patients in Wales and Northern Ireland.

Olaparib made more widely available on the NHS

More people with advanced ovarian cancer in Scotland will be able to benefit from a targeted cancer treatment, reports BBC Scotland. The drug, olaparib, which had previously been available to women whose cancer had come back after initial treatment, will now be an option for people with newly-diagnosed ovarian cancer that’s begun to spread to other parts of the body. Our news report has the details.

Olaparib has also been made more widely available on the NHS in England. It will now be an option for people whose cancer has come back after initial treatment, to help prolong the effects of chemotherapy.

New drug ‘starves’ triple negative breast cancer in mice

Researchers in the US have discovered a new way to stop triple negative breast cancer cells growing in the lab. The drug, which tags a key protein for destruction in cancer cells, also slowed tumour growth in mice with breast cancer, reports the Mail Online. It’s a fascinating new approach to treating breast cancer, but it’s still early days. The drug will need to be put to the test in clinical trials to see if it’s safe and can have the same benefits in people with breast cancer.

Children born from frozen embryos could be more likely to develop cancer

A Danish study carried out between 1996-2012 found that children born from frozen embryos following IVF were more than twice as likely to develop childhood cancer than those conceived naturally. But although the numbers reported in The Telegraph may sound alarming, childhood cancers are rare and so the actual risk of a child developing cancer is still very small.

New targeted treatment tested for leukaemia

A new drug for treating chronic myeloid leukaemia has been shown to be well tolerated in an early stage clinical trial. The study, which involved 150 patients who had already been treated with multiple drugs, found that asciminib was effective at killing cancer cells, without inadvertently killing healthy cells too. But despite the headline in the Express, it’s still early days yet. The drug needs to be tested in a larger group of people to see if it can help improve survival.

And finally…

New findings suggest that anastrozole, which can reduce a woman’s risk of breast cancer, continues to work for years after women stop taking it. Anastrozole blocks the production of the hormone oestrogen in post-menopausal women and is already available on the NHS, but BBC News report that only 1 in 10 women who are eligible for the drug have been taking it. Experts commented that while both anastrozole and a different drug, tamoxifen, can be taken by women with a higher risk of breast cancer, up until now doctors only knew about the long-term benefits of tamoxifen.

Lilly

from Cancer Research UK – Science blog https://ift.tt/2rOlUhJ

Focusing on a cancer cure masks progress, says charity

The Institute of Cancer Research has warned that focusing on the cure for cancer as the ‘holy grail’ of cancer research has undermined people’s understanding of how much progress has been made in the field. Researchers conducted a survey which analysed the public and patient opinion of cancer as a long-term, manageable disease. Reported in The Guardian, the results showed that only 28 out of 100 of people believe cancers can be controlled long-term despite the fact that, on average, people are living for more than 10 years after a cancer diagnosis.

Breast cancer treatment combo approved for NHS use in England

A third treatment combination has been approved for some patients with advanced breast cancer on the NHS in England, the Daily Mail reports. The treatment, which combines the targeted drug palbociclib and an injectable hormone therapy, was already an option for women who had not yet received hormone therapy but will now be available to those who have already completed this treatment. Similar drug combinations were approved for use for the same group of women earlier this year. The combination should also be available soon to patients in Wales and Northern Ireland.

Olaparib made more widely available on the NHS

More people with advanced ovarian cancer in Scotland will be able to benefit from a targeted cancer treatment, reports BBC Scotland. The drug, olaparib, which had previously been available to women whose cancer had come back after initial treatment, will now be an option for people with newly-diagnosed ovarian cancer that’s begun to spread to other parts of the body. Our news report has the details.

Olaparib has also been made more widely available on the NHS in England. It will now be an option for people whose cancer has come back after initial treatment, to help prolong the effects of chemotherapy.

New drug ‘starves’ triple negative breast cancer in mice

Researchers in the US have discovered a new way to stop triple negative breast cancer cells growing in the lab. The drug, which tags a key protein for destruction in cancer cells, also slowed tumour growth in mice with breast cancer, reports the Mail Online. It’s a fascinating new approach to treating breast cancer, but it’s still early days. The drug will need to be put to the test in clinical trials to see if it’s safe and can have the same benefits in people with breast cancer.

Children born from frozen embryos could be more likely to develop cancer

A Danish study carried out between 1996-2012 found that children born from frozen embryos following IVF were more than twice as likely to develop childhood cancer than those conceived naturally. But although the numbers reported in The Telegraph may sound alarming, childhood cancers are rare and so the actual risk of a child developing cancer is still very small.

New targeted treatment tested for leukaemia

A new drug for treating chronic myeloid leukaemia has been shown to be well tolerated in an early stage clinical trial. The study, which involved 150 patients who had already been treated with multiple drugs, found that asciminib was effective at killing cancer cells, without inadvertently killing healthy cells too. But despite the headline in the Express, it’s still early days yet. The drug needs to be tested in a larger group of people to see if it can help improve survival.

And finally…

New findings suggest that anastrozole, which can reduce a woman’s risk of breast cancer, continues to work for years after women stop taking it. Anastrozole blocks the production of the hormone oestrogen in post-menopausal women and is already available on the NHS, but BBC News report that only 1 in 10 women who are eligible for the drug have been taking it. Experts commented that while both anastrozole and a different drug, tamoxifen, can be taken by women with a higher risk of breast cancer, up until now doctors only knew about the long-term benefits of tamoxifen.

Lilly

from Cancer Research UK – Science blog https://ift.tt/2rOlUhJ

Emory soil analysis project leads to EPA site investigation

Emory professor Eri Saikawa (left) in the field with Historic Westside Gardens member and Westside resident Rosario Hernandez (center) and Xinyi Yao (right), an Emory student pursuing a master's degree in environmental sciences who is involved in the research project. (Photo by Carol Clark)

An Emory University collaboration with members of Atlanta’s Westside community, to test urban soil for contaminants, has led to a site investigation by the U.S. Environmental Protection Agency (EPA). The ongoing community collaboration is funded by Emory’s HERCULES Exposome Research Center, dedicated to understanding how environmental exposures affect health and community well-being.

The EPA told the Atlanta Journal-Constitution that it is continuing to collect samples and has so far identified 64 sites where the soil contains elevated levels of lead — a dangerous neurotoxin. The agency plans to begin decontaminating properties, possibly by removing and replacing soil, in the first quarter of next year, at no expense to residents or homeowners, according to the AJC. The report also appeared in Georgia Health News.

“It’s important for people to know that soil contamination by heavy metals can be serious,” says Eri Saikawa, an associate professor of environmental sciences at Emory and the lead researcher on the original project that sparked the EPA investigation. “If you are thinking about gardening in an urban area, or if children are playing in your yard, it makes sense to test your soil and make sure that it’s not contaminated.”

Read the full story here.

Related:
Creating an atmosphere for change
The growing role of farming and nitrous oxide in climate change

from eScienceCommons https://ift.tt/2qTYUxq

Emory professor Eri Saikawa (left) in the field with Historic Westside Gardens member and Westside resident Rosario Hernandez (center) and Xinyi Yao (right), an Emory student pursuing a master's degree in environmental sciences who is involved in the research project. (Photo by Carol Clark)

An Emory University collaboration with members of Atlanta’s Westside community, to test urban soil for contaminants, has led to a site investigation by the U.S. Environmental Protection Agency (EPA). The ongoing community collaboration is funded by Emory’s HERCULES Exposome Research Center, dedicated to understanding how environmental exposures affect health and community well-being.

The EPA told the Atlanta Journal-Constitution that it is continuing to collect samples and has so far identified 64 sites where the soil contains elevated levels of lead — a dangerous neurotoxin. The agency plans to begin decontaminating properties, possibly by removing and replacing soil, in the first quarter of next year, at no expense to residents or homeowners, according to the AJC. The report also appeared in Georgia Health News.

“It’s important for people to know that soil contamination by heavy metals can be serious,” says Eri Saikawa, an associate professor of environmental sciences at Emory and the lead researcher on the original project that sparked the EPA investigation. “If you are thinking about gardening in an urban area, or if children are playing in your yard, it makes sense to test your soil and make sure that it’s not contaminated.”

Read the full story here.

Related:
Creating an atmosphere for change
The growing role of farming and nitrous oxide in climate change

from eScienceCommons https://ift.tt/2qTYUxq