  We present high angular resolution SMA and Spitzer observations toward the
Bok globule CB17. SMA 1.3mm dust continuum images reveal within CB17 two
sources with an angular separation of about 21" (about 5250 AU at a distance of
250 pc). The northwestern continuum source, referred to as CB17 IRS, dominates
the infrared emission in the Spitzer images, drives a bipolar outflow extending
in the northwest-southeast direction, and is classified as a low luminosity
Class0/I transition object (L_bol ~ 0.5 L_sun). The southeastern continuum
source, referred to as CB17 MMS, has faint dust continuum emission in the SMA
1.3mm observations (about 6 sigma detection; ~3.8 mJy), but is not detected in
the deep Spitzer infrared images at wavelengths from 3.6 to 70 micron. Its
bolometric luminosity and temperature, estimated from its spectral energy
distribution, are less than 0.04 L_sun and 16 K, respectively. The SMA CO(2-1)
observations suggest that CB17 MMS may drive a low-velocity molecular outflow
(about 2.5 km/s), extending in the east-west direction. Comparisons with
prestellar cores and Class0 protostars suggest that CB17 MMS is more evolved
than prestellar cores but less evolved than Class0 protostars. The observed
characteristics of CB17 MMS are consistent with the theoretical predictions
from radiative/magneto hydrodynamical simulations of a first hydrostatic core,
but there is also the possibility that CB17 MMS is an extremely low luminosity
protostar deeply embedded in an edge-on circumstellar disk. Further
observations are needed to study the properties of CB17 MMS and to address more
precisely its evolutionary stage.
