INFRARED FLUX EXCESSES FROM HOT SUBDWARFS

Observations of 27 hot subdwarf stars and white dwarfs have been perfo rmed with an IR photometer in a search for excess fluxes in the JHK ba nds. 22 of the objects are observed for the first time in the infrared . In 11 of the stars a significant excess flux was found, 2 of which a re new discoveries: GD 274 and GD 299. We confirm the suspicion of Moe hler et al. (1990) that PG0232+095 is a composite system, and we reinf orce the suggestion of Thejll et al. (1991, 1994a) that Feige 34 is a composite system. The excesses are most likely due to companion stars, mainly of spectral types A - K. We estimate the subdwarf gravities, a ssuming zero-age main sequence companions, and thus find upper limits on log(g). For the hot sdO Feige 34 we estimate from the published tri gonometric parallaxes an absolute magnitude M(v)(F34)=5.6(-1.6)(+0.9) and surface gravity log(g(pi))=6.8(-0.7)(+0.3).