Post by Andrei Tchentchik on Jun 22, 2019 14:27:25 GMT 2
(.#204).- Discovery of 2 stars near the Sun.
Discovery of 2 stars near the Sun.
By Tristan Vey - Updated on 29 / 03/2013 at 19:02
Artist's impression of the two brown dwarfs and the Sun as it appears in their sky.
INFOGRAPHY - This stellar pair is composed of two brown dwarfs located a little more than six light years away from us, making it the 3rd closest system.
This is the closest stellar system discovered for nearly a century. Composed of two brown dwarfs, kind of small extinct suns, it was detected by Kevin Luhman, astrophysicist at Penn State University, about 6.5 light-years from the Sun. The astronomer reports his discovery in The Astrophysical Journal Letters in April. Only four stars are closer to us. First the triple star formed by Alpha Centauri A, B and Proxima Centauri (respectively a yellow dwarf, an orange dwarf and a red dwarf) located a little over 4 light years and the star of Barnard, a dwarf red located 6 light years away.
To detect this system called WISE 1049-5319, Kevin Luhman peeled the data collected by the WISE satellite for 13 months - until the end of 2011. This telescope systematically scans the sky in the infrared field which allowed it to detect the weak heat emissions of these two neighbors. These two stars are indeed too small for the forces of gravity could trigger the nuclear fusion reaction in their heart. Their temperature must not exceed 2000 ° C and therefore emit no visible light. Moreover, if we call them stars, the brown dwarfs actually hold more of the big gas planet Jupiter than the little yellow star of the Sun type.
This partly explains why we only discover them today - the first brown dwarf was found in 1994. Another reason is their location in the sky. They are located in the plane of our galaxy, the Milky Way, a region in which astronomers do not seek priority because the observations are more difficult. The signatures of brown dwarfs are indeed embedded among the billions of parasitic infrared sources that are visible stars.
Our nearest neighbor may be lurking in the shadows
It took a more precise observation to distinguish the presence of two distinct stars.
Kevin Luhman had also detected a spot moving quickly in the sky. This sufficed to presume that it was a close object but did not give much more information about its nature. It was by zooming in on a larger telescope, the Gemini, that he realized it was a binary system.
Astronomers will now try to detect planets around this system. We know since last year that our neighbor Alpha Centauri has a planet. But around this much less dazzling system and just as close, the observations could be greatly facilitated. Not to mention that the discovery of these two brown dwarfs raises the possibility that the closest neighbor of the Sun has perhaps still escaped us so far.
F I N .
Discovery of 2 stars near the Sun.
By Tristan Vey - Updated on 29 / 03/2013 at 19:02
Artist's impression of the two brown dwarfs and the Sun as it appears in their sky.
INFOGRAPHY - This stellar pair is composed of two brown dwarfs located a little more than six light years away from us, making it the 3rd closest system.
This is the closest stellar system discovered for nearly a century. Composed of two brown dwarfs, kind of small extinct suns, it was detected by Kevin Luhman, astrophysicist at Penn State University, about 6.5 light-years from the Sun. The astronomer reports his discovery in The Astrophysical Journal Letters in April. Only four stars are closer to us. First the triple star formed by Alpha Centauri A, B and Proxima Centauri (respectively a yellow dwarf, an orange dwarf and a red dwarf) located a little over 4 light years and the star of Barnard, a dwarf red located 6 light years away.
To detect this system called WISE 1049-5319, Kevin Luhman peeled the data collected by the WISE satellite for 13 months - until the end of 2011. This telescope systematically scans the sky in the infrared field which allowed it to detect the weak heat emissions of these two neighbors. These two stars are indeed too small for the forces of gravity could trigger the nuclear fusion reaction in their heart. Their temperature must not exceed 2000 ° C and therefore emit no visible light. Moreover, if we call them stars, the brown dwarfs actually hold more of the big gas planet Jupiter than the little yellow star of the Sun type.
This partly explains why we only discover them today - the first brown dwarf was found in 1994. Another reason is their location in the sky. They are located in the plane of our galaxy, the Milky Way, a region in which astronomers do not seek priority because the observations are more difficult. The signatures of brown dwarfs are indeed embedded among the billions of parasitic infrared sources that are visible stars.
Our nearest neighbor may be lurking in the shadows
It took a more precise observation to distinguish the presence of two distinct stars.
Kevin Luhman had also detected a spot moving quickly in the sky. This sufficed to presume that it was a close object but did not give much more information about its nature. It was by zooming in on a larger telescope, the Gemini, that he realized it was a binary system.
Astronomers will now try to detect planets around this system. We know since last year that our neighbor Alpha Centauri has a planet. But around this much less dazzling system and just as close, the observations could be greatly facilitated. Not to mention that the discovery of these two brown dwarfs raises the possibility that the closest neighbor of the Sun has perhaps still escaped us so far.
F I N .
