  SAX J1711.6-3808 is an X-ray transient in the Galactic bulge that was active
from January through May of 2001 and whose maximum 1-200 keV luminosity was
measured to be 5X10-9 erg/s/cm2 which is less than ~25% of the Eddington limit,
if placed at a distance equal to that of the galactic center. We study the
X-ray data that were taken of this moderately bright transient with instruments
on BeppoSAX and RXTE. The spectrum shows two interesting features on top of a
Comptonized continuum commonly observed in low-state X-ray binaries: a broad
emission feature peaking at 7 keV and extending from 4 to 9 keV, and a soft
excess with a color temperature below 1 keV which reveals itself only during
one week of data. High time-resolution analysis of 412 ksec worth of data fails
to show bursts, coherent or high-frequency quasi-periodic oscillations. Given
the dynamic range of the flux measurements, this would be unusual if a neutron
star were present. SAX J1711.6-3808 appears likely to contain a black hole. No
quiescent optical counterpart could be identified in archival data within the
5"-radius XMM error circle, but the limits are not very constraining because of
heavy extinction (Av=16).

Astrophysics