Astronomers discovered a record-breakingly separated pair of brown dwarfs in a binary system
(The Astrophysical Journal Letters, 2022 / William Pendrill)
Astronomers have discovered the most strongly separated brown dwarf binary system known.
The distance between the components of CWISE J0146-0508AB is 129 astronomical units.
It is assumed that such a system could have formed in a region of star formation with a relatively low density, which allowed it to maintain its structure for a long time.
Almost half of the stars in our galaxy are part of binary or multiple systems, and there is a dependence of the proportion of multiple systems on the mass of stars
From 69% in the case of massive stars of spectral type A to 25%–30% in the case of red dwarfs.
Brown dwarfs are larger in mass than giant planets, but smaller than stars, and they are often found in binary systems.
Approximately 10% to 20% of the known bodies of this type form brown dwarf binary systems
The distance between them usually is a few astronomical units, and at a maximum - up to more than 20 astronomical units.
Studies of such systems, as in the case of stars, allow us to understand how they formed and evolved.
A team of astronomers led by Emma Softich of the University of Arizona announced the discovery of a new brown dwarf binary system: CWISE J0146-0508AB
The scientist discovered it while analyzing results from the Backyard Worlds: Planet 9 citizen science project, one of whose goals is to search for brown dwarfs.
The scientists first identified a candidate system among a sample of 3,000 brown dwarfs.
Then confirmed the discovery based on optical observations from sky surveys such as DES and Pan-STARRS and spectroscopic observations made using the NIRES instrument mounted on the Keck Observatory.
The binary system lies 130.4 light-years from Earth and is estimated to be between 0.5 and 10 billion years old.
The masses and effective temperatures of the components were 72–74 Jupiter masses and 1720 Kelvin for CWISE J0146-0508A and 64–66 Jupiter masses and 1340 Kelvin for CWISE J0146-0508B.
The spectral types of the dwarfs are defined as L4 and L8, and the distance between them is 129 astronomical units, which has become a record large value.
It is assumed that CWISE J0146-0508AB could have formed from a single gas and dust cloud in a star-forming region with a relatively low density, which allowed the system to maintain its structure for a long time.
Source:
The Astrophysical Journal Letters: https://iopscience.iop.org/article/10.3847/2041-8213/ac51d8
Europa Press: https://www.europapress.es/ciencia/astronomia/noticia-excepcional-binario-enanas-marrones-separado-129-ua-20220218110945.html