  IRAS 23385+6053 is a Young Stellar Object with luminosity 16,000 solar
luminosities at a kinematic distance of 4.9 kpc. This candidate precursor of an
ultracompact HII region is associated with a millimeter source detected at the
JCMT but is undetected at centimeter wavelengths with the VLA. We observed this
source with the OVRO millimeter array at 3.4 mm in the continuum, HCO+(1-0),
H13CO+(1-0) and SiO(v=0, 2-1) line emission, and with CAM aboard ISO at 6.75
and 15 um. The IRAS source is coincident with a 3.4 mm compact (r~0.048 pc) and
massive (M~370 solar masses) core, which is undetected at 15 um to a 3 sigma
level of 6 mJy; this is compatible with the derived H2 column density of
2x10(24) and the estimated visual extinction of about 2000 mag. We find
L(submm)/L(bol)>10(-3) and M(env)/M(star)>>1, typical of Class 0 objects. The
source is also associated with a compact outflow characterized by a size
similar to the core radius, a dynamical timescale of about 7,000 years, and a
mass loss rate of about 10(-3) solar masses/year. The axis of the outflow is
oriented nearly perpendicular to the plane of the sky, ruling out the
possibility that the non-detection at 15 um is the result of a geometric
effect. All these properties suggest that IRAS 23385+6053 is the first example
of a bona fide massive Class 0 object.
