Quiescent X-Ray Emission from an Evolved Brown Dwarf?
Abstract
I report on the X-ray detection of Gl 569Bab. During a 25 ks Chandra observation, the binary brown dwarf is for the first time spatially separated in X-rays from the flare star primary Gl 569A. Companionship to Gl 569A constrains the age of the brown dwarf pair to ~300-800 Myr. The observation presented here is only the second X-ray detection of an evolved brown dwarf. About half of the observing time is dominated by a large flare on Gl 569Bab; the remainder is characterized by weak and nonvariable emission just above the detection limit. This emission-if not related to the afterglow of the flare-represents the first detection of a quiescent corona on a brown dwarf, representing an important piece in the puzzle of dynamos in the substellar regime.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 2004
- DOI:
- 10.1086/426121
- arXiv:
- arXiv:astro-ph/0409617
- Bibcode:
- 2004ApJ...615L.153S
- Keywords:
-
- Stars: Coronae;
- Stars: Flare;
- Stars: Individual: Alphanumeric: Gl 569Bab;
- Stars: Low-Mass;
- Brown Dwarfs;
- X-Rays: Stars;
- Astrophysics
- E-Print:
- to appear in ApJL