The Substellar Domain in the ɛ Orionis Cluster

Béjar, V. J. S.; Rebolo, R.; Zapatero Osorio, M. R.; Caballero, J. A.
Bibliographical reference

The Future of Cool-Star Astrophysics: 12th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun (2001 July 30 - August 3), eds. A. Brown, G.M. Harper, and T.R. Ayres, (University of Colorado), 2003, p. 651-657.

Advertised on:
10
2003
Number of authors
4
IAC number of authors
0
Citations
2
Refereed citations
1
Description
We present an IZ photometric survey covering a total area of about 1000 arcmin2 around the ɛ Orionis young massive star (˜10 Myr, d=412 pc) and reaching a limiting magnitude I=22. From the resulting I, I-Z color-magnitude diagram we have selected 123 red candidates in the interval I=15--22 mag, which according to evolutionary models corresponds to masses between 0.40 and 0.020 M&odot, i.e, approaching the deuterium burning mass limit. We have obtained follow-up J-band photometry for half of our photometric candidates. The I, I-J color-magnitude diagram and low-resolution optical spectroscopy of four of them suggest that we have identified a rather abundant population of young low-mass stars and brown dwarfs. We compare our findings with previous works in other young clusters.