New Brown Dwarf Companions to Young Stars in Scorpius-Centaurus
Abstract
We present the discoveries of three faint companions to young stars in the Scorpius-Centaurus region, imaged with the NICI instrument on Gemini South. We have confirmed all three companions through common proper motion tests. Follow-up spectroscopy has confirmed two of them, HIP 65423 B and HIP 65517 B, to be brown dwarfs, while the third, HIP 72099 B, is more likely a very low mass star just above the hydrogen burning limit. The detection of wide companions in the mass range of ~40-100 M jup complements previous work in the same region, reporting detections of similarly wide companions with lower masses, in the range of ~10-30 M jup. Such low masses near the deuterium burning limit have raised the question of whether those objects formed like planets or stars. The existence of intermediate objects as reported here could represent a bridge between lower-mass companions and stellar companions, but in any case demonstrate that mass alone may not provide a clear-cut distinction for the formation of low-mass companions to stars.
Based on Gemini observations from programs GS-2011A-Q-44, GS-2012A-Q-18, and GS-2012A-DD-6, and on ESO observations from program 089.C-0422(A).- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 2012
- DOI:
- 10.1088/2041-8205/758/1/L2
- arXiv:
- arXiv:1209.2121
- Bibcode:
- 2012ApJ...758L...2J
- Keywords:
-
- binaries: general;
- brown dwarfs;
- planetary systems;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 9 pages, 5 figures, accepted for publication in ApJL