From ground-based telescopes, the so-called “Ant Nebula” (Menzel 3, or Mz 3) resembles the head and thorax of a garden-variety ant. Image via NASA, ESA and the Hubble Heritage Team (STScI/AURA).
Observations by the European Space Agency’s (ESA) Herschel space observatory of an unusual laser emission from the Ant Nebula suggest the presence of a double star system hidden at the nebula’s heart. That’s according to a new study published May 16, 2018, in the peer-reviewed journal Monthly Notices of the Royal Astronomical Society.
When low- to middle-weight stars – like our sun – approach the end of their lives they eventually become dense, white dwarf stars. In the process, they cast off their outer layers of gas and dust into space, creating a kaleidoscope of intricate patterns known as a planetary nebula.
The infrared Herschel observations suggest that the dramatic demise of the central star in the core of the Ant Nebula is even more theatrical than what might be implied by its colorful appearance in visible images – such as the image at the top of this post. The new data, say the study authors, reveal the Ant Nebula also beams intense laser emission from its core.
According to an ESA statement:
While lasers in everyday life today might mean special visual effects in music concerts, in space, focused emission is detected at different wavelengths under specific conditions. Only a few of these space infrared lasers are known.
By coincidence, astronomer Donald Menzel who first observed and classified this particular planetary nebula in the 1920s (it is officially known as Menzel 3 after him) was also one of the first to suggest that in certain conditions natural ‘light amplification by stimulated emission of radiation’ – from which the acronym ‘laser’ derives – could occur in gaseous nebulae. This was well before the discovery and first successful operation of lasers in laboratories in 1960, an occasion which is now celebrated annually on May 16 as International Day of Light.
Stellar evolution. Read more about this image. Image via ESA.
Isabel Aleman of University of Sao Paulo, Brazil, is the paper’s lead author She said:
When we observe Menzel 3, we see an amazingly intricate structure made up of ionized gas, but we cannot see the object in its center producing this pattern.
Thanks to the sensitivity and wide wavelength range of the Herschel observatory, we detected a very rare type of emission called hydrogen recombination line laser emission, which provided a way to reveal the nebula’s structure and physical conditions.
This kind of laser emission needs very dense gas close to the star. When the astronomers compared the observations with models, they found that the density of the laser-emitting gas is around 10 thousand times higher than that of the gas seen in typical planetary nebulae and in the lobes of the Ant Nebula itself.
Normally, the region close to the dead star – close in this case being about the distance of Saturn from the sun – is quite empty, because most of its material is ejected outwards. Any lingering gas would soon fall back onto it. According to study co-author Albert Zijlstra of University of Manchester:
The only way to keep gas close to the star is if it is orbiting around it in a disc. In this case, we have actually observed a dense disc in the very centre that is seen approximately edge-on. This orientation helps to amplify the laser signal. The disc suggests the white dwarf has a binary companion, because it is hard to get the ejected gas to go into orbit unless a companion star deflects it in the right direction.
The Herschel telescope in the clean room. Image via ESA.
Astronomers have not yet seen the expected second star, but they think that the mass from the dying companion star is being ejected and then captured by the compact central star of the original planetary nebula, producing the disc where the laser emission is produced.
Göran Pilbratt is ESA’s Herschel project scientist. He said:
This study suggests that the distinctive Ant Nebula as we see it today was created by the complex nature of a binary star system, which influences the shape, chemical properties, and evolution in these final stages of a star’s life.
Bottom line: Observations by ESA’s Hershel space telescope suggest the presence of a double star system hidden at the heart of the Ant Nebula.
from EarthSky https://ift.tt/2Lh5xin
From ground-based telescopes, the so-called “Ant Nebula” (Menzel 3, or Mz 3) resembles the head and thorax of a garden-variety ant. Image via NASA, ESA and the Hubble Heritage Team (STScI/AURA).
Observations by the European Space Agency’s (ESA) Herschel space observatory of an unusual laser emission from the Ant Nebula suggest the presence of a double star system hidden at the nebula’s heart. That’s according to a new study published May 16, 2018, in the peer-reviewed journal Monthly Notices of the Royal Astronomical Society.
When low- to middle-weight stars – like our sun – approach the end of their lives they eventually become dense, white dwarf stars. In the process, they cast off their outer layers of gas and dust into space, creating a kaleidoscope of intricate patterns known as a planetary nebula.
The infrared Herschel observations suggest that the dramatic demise of the central star in the core of the Ant Nebula is even more theatrical than what might be implied by its colorful appearance in visible images – such as the image at the top of this post. The new data, say the study authors, reveal the Ant Nebula also beams intense laser emission from its core.
According to an ESA statement:
While lasers in everyday life today might mean special visual effects in music concerts, in space, focused emission is detected at different wavelengths under specific conditions. Only a few of these space infrared lasers are known.
By coincidence, astronomer Donald Menzel who first observed and classified this particular planetary nebula in the 1920s (it is officially known as Menzel 3 after him) was also one of the first to suggest that in certain conditions natural ‘light amplification by stimulated emission of radiation’ – from which the acronym ‘laser’ derives – could occur in gaseous nebulae. This was well before the discovery and first successful operation of lasers in laboratories in 1960, an occasion which is now celebrated annually on May 16 as International Day of Light.
Stellar evolution. Read more about this image. Image via ESA.
Isabel Aleman of University of Sao Paulo, Brazil, is the paper’s lead author She said:
When we observe Menzel 3, we see an amazingly intricate structure made up of ionized gas, but we cannot see the object in its center producing this pattern.
Thanks to the sensitivity and wide wavelength range of the Herschel observatory, we detected a very rare type of emission called hydrogen recombination line laser emission, which provided a way to reveal the nebula’s structure and physical conditions.
This kind of laser emission needs very dense gas close to the star. When the astronomers compared the observations with models, they found that the density of the laser-emitting gas is around 10 thousand times higher than that of the gas seen in typical planetary nebulae and in the lobes of the Ant Nebula itself.
Normally, the region close to the dead star – close in this case being about the distance of Saturn from the sun – is quite empty, because most of its material is ejected outwards. Any lingering gas would soon fall back onto it. According to study co-author Albert Zijlstra of University of Manchester:
The only way to keep gas close to the star is if it is orbiting around it in a disc. In this case, we have actually observed a dense disc in the very centre that is seen approximately edge-on. This orientation helps to amplify the laser signal. The disc suggests the white dwarf has a binary companion, because it is hard to get the ejected gas to go into orbit unless a companion star deflects it in the right direction.
The Herschel telescope in the clean room. Image via ESA.
Astronomers have not yet seen the expected second star, but they think that the mass from the dying companion star is being ejected and then captured by the compact central star of the original planetary nebula, producing the disc where the laser emission is produced.
Göran Pilbratt is ESA’s Herschel project scientist. He said:
This study suggests that the distinctive Ant Nebula as we see it today was created by the complex nature of a binary star system, which influences the shape, chemical properties, and evolution in these final stages of a star’s life.
Bottom line: Observations by ESA’s Hershel space telescope suggest the presence of a double star system hidden at the heart of the Ant Nebula.
from EarthSky https://ift.tt/2Lh5xin
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