Candidate free-floating super-Jupiters in the young σ Orionis open cluster
Abstract
Context: Free-floating substellar candidates with estimated theoretical masses of as low as ∼5 Jupiter masses have been found in the ∼3 Myr old
Aims: We propose to search for objects of yet lower masses in the cluster and determine the shape of the mass function at low mass.
Methods: Using new- and (re-analysed) published IZJHKs[3.6]-[8.0]-band data of an area of 840 arcmin2, we performed a search for LT-type cluster member candidates in the magnitude range J=19.5-21.5 mag, based on their expected magnitudes and colours.
Results: Besides recovering the T type object
Conclusions: We present S Ori 73, a new candidate T type and candidate σ Orionis member of a few Jupiter masses. Our result suggests a possible turnover in the substellar mass spectrum below ∼6 Jupiter masses, which could be investigated further by wider and deeper photometric surveys.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- November 2009
- DOI:
- 10.1051/0004-6361/200912210
- arXiv:
- arXiv:0909.0802
- Bibcode:
- 2009A&A...506.1169B
- Keywords:
-
- stars: luminosity function;
- mass function;
- Galaxy: open clusters and associations: individual: σ Orionis;
- stars: low-mass;
- brown dwarfs;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 15 pages, 13 figures, 5 tables, and appendix containing 5 figures