Carnegie Institution for Science | 2018 Aug 17
The line that separates stars from brown dwarfs may soon be clearer thanks to new work led by Carnegie’s Serge Dieterich. Published by The Astrophysical Journal, his team’s findings demonstrate that brown dwarfs can be more massive than astronomers previously thought.
To shine bright, stars need the energy derived from the fusion of hydrogen atoms deep in their interiors. If too small, hydrogen fusion can’t occur, so the object cools, darkens, and turns into something called a brown dwarf.
Many researchers are trying to determine the mass, temperature, and brightness of objects on both sides of this divide. ...
The latest theoretical models predict that the boundary separating stars from brown dwarfs occurs in objects that are between 70 to 73 times the mass of Jupiter, or about 7 percent the mass of our Sun, but the results from Dieterich and team question this prediction.
Dieterich’s team observed two brown dwarfs, called Epsilon Indi B and Epsilon Indi C, that are part of a system that also includes a star of medium luminosity—Epsilon Indi A. The two brown dwarfs are much too faint to be stars, but their masses are respectively 75 and 70 times that of Jupiter, according to the researchers’ findings. ...
Dynamical Masses of Eps Ind B and C: Two Massive Brown Dwarfs
at the Edge of the Stellar-Substellar Boundary ~ Sergio B. Dieterich et al
- arXiv.org > astro-ph > arXiv:1807.09880 > 25 Jul 2018