Investigating Possible Binarity for GJ 229B
Abstract
GJ 229B, the first type-T brown dwarf to be discovered, has presented a tension between comparisons with evolutionary models and the larger-than-expected mass and radius values derived from spectroscopic and astrometric observations. We examine the hypothesis that GJ 229B is actually a binary substellar object by using two grid-based fits using evolutionary models to explore the range of mass ratios of the possible binary components. We find that the best-fit component values are most consistent with a roughly 2:1 binary mass ratio and an age range of 2-6 Gyr. The observed temperatures, masses, and apparent radii match expected values from evolutionary models for a binary much better than a single-object model, but more detailed observations and modeling are needed to definitively confirm the binary hypothesis.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 2023
- DOI:
- 10.3847/2041-8213/acdd76
- arXiv:
- arXiv:2306.08450
- Bibcode:
- 2023ApJ...951L..25H
- Keywords:
-
- Brown dwarfs;
- T dwarfs;
- Binary stars;
- Stellar atmospheres;
- 185;
- 1679;
- 154;
- 1584;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 9 pages, 3 figures, 2 tables, accepted for publication in ApJL