A group of astrophysicists have found the closest known brown dwarf, Luhman 16A which shows signs of cloud bands similar to those seen on Jupiter and Saturn

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  A group of astrophysicists have found the closest known brown dwarf, Luhman 16A which shows signs of cloud bands similar to those seen on Jupiter and Saturn

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1. Scientists used the technique of polarimetry to determine the properties of atmospheric clouds outside of the solar system.
2. The concept of polarimetry technique was put forth by Indian astrophysicist Sujan Sengupta, that the light emitted by a cloudy brown dwarf, or reflected off an extrasolar planet, will be polarised. So it is the study of polarization. 
3. Polarization is a property of light that represents the direction that the light wave oscillates. 
4. When light is reflected off of particles it can favour a certain angle of polarization. By measuring the preferred polarization of light from a distant system, astronomers can deduce the presence of clouds.
5. But in case of Luhman 16A, the researchers have found the actual structure of the clouds (not only their presence).
6. Luhman 16A is part of a binary system (Luhman 16) containing a second brown dwarf, Luhman 16B. This pair of brown dwarfs Luhman 16A and Luhman 16B orbit each other. It is situated at a distance of about 6.5 light years from the Sun and the third closest system to the Sun after Alpha Centauri and Barnard’s star. Luhman 16B shows no sign of stationary cloud bands, instead showing evidence of more irregular, patchy clouds. 
7. Luhman 16B, therefore, has noticeable brightness variations as a result of its cloudy features, unlike Luhman 16A which has less brightness variation due to a band of clouds.
8. Understanding the cloud system over a brown dwarf can shed light on the pressure, temperature and climate on the surface of the celestial body.
9. Brown dwarfs are also called failed stars, because their masses are heavier than planets but lighter than stars. Due to their small masses, they are unable to sustain fusion of their hydrogen to produce energy.
10. It is believed that some of the more massive brown dwarfs fuse deuterium or lithium and glow faintly.
11. Binary stars are two stars orbiting a common center of mass.

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