AAS Meeting #193 - Austin, Texas, January 1999
Session 73. Young Stars
Display, Friday, January 8, 1999, 9:20am-6:30pm, Exhibit Hall 1

## [73.15] A Candidate Substellar Companion to CoD -33\circ7795 (TWA 5)

P.J. Lowrance, C.M. McCarthy, E.E. Becklin, B. Zuckerman (UCLA), G. Schneider (Arizona), R.A. Webb (UCLA), D. C. Hines, F. J. Low, M. J. Rieke, R. I. Thompson (Arizona), B.A. Smith, R. Meier (IFA), R.J. Terrile (JPL), J.D. Kirkpatrick (IPAC), D.W. Koerner (UPenn)

We present the discovery of a candidate substellar object as part of the NICMOS Instrument Design Team's survey of young stars in the solar vicinity using the sensitivity and spatial resolution afforded by the NICMOS coronagraph on the Hubble Space Telescope. The H=12.1 mag object was discovered approximately 2'' from the TW Hydrae Association member CoD -33\circ7795 (TWA 5), and the infrared photometry implies a spectral type M8-M8.5, with a temperature of ~2650K. We estimate that the probability of a chance alignment with a background object of this nature is < 2 \times 10-5, and therefore postulate the object (TWA 5B) is physically associated at a projected separation of 100 AU. Given the youth of the primary (~ 10 Myr), current brown dwarf cooling models predict a mass of approximately 20 Jupiter masses for the companion.

This work is supported in part by NASA grant NAG 5-3042 to the University of Arizona NICMOS Instrument Design Team. This poster is based on observations obtained with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS 5-26555.