For the past five years we have been carrying out a coronagraphic survey of
nearby stars using the Johns Hopkins Tip-Tilt Coronagraph. Last year we have
identified a common proper motion companion to the nearby star Gliese 229.
This companion has very peculiar colors (blue in the near-IR and very red in
the optical). We report broad-band photometry of the object from 0.7 micron to
10 microns. The bolometric luminosity is 6¥10 -6 LSun. Strong absorption
features and bands due to methane and water (steam) are seen. We conclude that
this is a brown dwarf with an effective temperature of 900 K. Strong bands of
refractory oxides and hydrides (TiO, VO, FeH) are conspicuously missing from
the Keck optical spectrum - similar to the situation in Jupiter. We conclude
that the metals have rained out of the atmosphere.
