In the realm of astrophysics, exciting discoveries are endless. Lately, a group of astrophysicists has shed light on a fascinating fact about Luhman 16A, the closest known brown dwarf. The observations reveal that this brown dwarf displays cloud bands much like those found on Jupiter and Saturn.
The application of a technique known as polarimetry facilitated the substantial discovery of the atmospheric clouds properties beyond our solar system. This method relies on the study of light polarization, which represents the oscillation direction of the light wave.
The Science Behind Polarimetry
Polarimetry, an innovative concept propounded by Indian astrophysicist Sujan Sengupta, suggests that the light emitted by a cloudy brown dwarf or reflected off an extrasolar planet would be polarized. Polarization occurs when light waves oscillate in a definite direction.
When light reflects off particles, a certain angle of polarization may gain preference. Thus, astronomers can infer the existence of clouds by gauging the preferred light polarization from distant systems. In the case of Luhman 16A, researchers not only confirmed the presence of clouds but also uncovered their actual structure.
The Versatility of Polarimetry
Polarimetry is a versatile technique, not confined to brown dwarfs alone. It holds potential applicability to studying exoplanets revolving around distant stars and even stars themselves. Nevertheless, brown dwarfs’ light proves to be the prime choice for undertaking these studies due to its optimal qualities.
Unveiling the Dual Brown Dwarfs: Luhman 16A and Luhman 16B
Luhman 16A forms part of a binary system, Luhman 16, along with another brown dwarf, Luhman 16B. These siblings are in constant orbit around each other in the third closest system to the Sun, following Alpha Centauri and Barnard’s Star.
Despite sharing similar masses and temperatures and presumably simultaneously forming, these two brown dwarfs show remarkably different weather conditions. Unlike Luhman 16A that shows less brightness variation due to a band of clouds, Luhman 16B displays evidence of irregular, patchy clouds, contributing to noticeable brightness variations.
Understanding these cloud systems illuminates the surface pressure, temperature, and climate of these celestial bodies, giving us more insights into their structures and behaviors.
Understanding Brown Dwarfs
Often referred to as failed stars, brown dwarfs have weights heavier than planets but lighter than stars. Their small masses prevent them from maintaining hydrogen fusion to produce energy. However, it’s presumed that the more massive brown dwarfs could fuse deuterium or lithium and emit faint light.
Binary Stars Systems Explained
Binary stars constitute two stars that orbit a common center of mass. The brighter star is primarily classified, while the dimmer one gets the secondary classification. If both stars share equal brightness, the discoverer’s designation takes precedence. The importance of binary stars in astrophysics is unparalleled as their orbit calculations allow for the direct determination of the component stars’ masses, leading to the indirect estimation of other stellar parameters like radius and density.
