University of Notre Dame | 2016 Apr 06
[img3="A team led by Justin Crepp has discovered HD 4747 B, a rare brown dwarf. As a new mass, age and metallicity benchmark, HD 4747 B will serve as a laboratory for precision astrophysics to test theoretical models. (Credit: J. Crepp)"]https://news.nd.edu/assets/195538/origi ... ery_v2.jpg[/img3][hr][/hr]A team led by Justin Crepp, the Frank M. Freimann Assistant Professor of Physics at the University of Notre Dame, has discovered a rare brown dwarf, a faint object with properties in between that of a star and planet. In addition to taking its picture for the first time, Crepp’s team also determined the brown dwarf’s mass, age and composition — essential information that can be used to “benchmark” the study of these elusive objects.
Brown dwarfs are objects thought to have initially begun the process of forming a star but were somehow interrupted before they accumulated sufficient mass and core pressure to ignite nuclear fusion — the process by which the Sun ultimately releases energy in the form of light. An important developmental bridge between bona fide stars and exoplanets, brown dwarfs are very difficult to study because their faint glow fades with time due to a lack of sustained nuclear reactions. The discovery of the object, which goes by the name HD 4747 B, was facilitated by 18 years of precise spectral measurements of the star that indicated it hosts an orbiting companion.
“We suspect that these companions form at the same time and from the same material,” Crepp said. “As such, you can infer physical properties of the brown dwarf from its parent star, like age and composition. There are no other objects for which we know the mass, age and the metallicity simultaneously and also independent of the light that the companion gives off. We can therefore use HD 4747 B as a test-bed to study brown dwarfs, enabling precision astrophysics studies for a directly imaged substellar object.” ...
The TRENDS High-Contrast Imaging Survey. VI. Discovery
of a Mass, Age, and Metallicity Benchmark Brown Dwarf - Justin R. Crepp et al
- arXiv.org > astro-ph > arXiv:1604.00398 > 01 Apr 2016