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).