  We present follow-up observations of an optical transient (OT) discovered by
ROTSE on Jan. 21, 2009. Photometric monitoring was carried out with ROTSE-IIIb
in the optical and Swift in the UV up to +70 days after discovery. The light
curve showed a fast rise time of ~10 days followed by a steep decline over the
next 60 days, which was much faster than that implied by 56Ni - 56Co
radioactive decay. The SDSS DR10 database contains a faint, red object at the
position of the OT, which appears slightly extended. This and other lines of
evidence suggest that the OT is of extragalactic origin, and this faint object
is likely the host galaxy. A sequence of optical spectra obtained with the
9.2-m Hobby-Eberly Telescope (HET) between +8 and +45 days after discovery
revealed a hot, blue continuum with no visible spectral features. A few weak
features that appeared after +30 days probably originated from the underlying
host. Fitting synthetic templates to the observed spectrum of the host galaxy
revealed a redshift of z = 0.19. At this redshift the peak magnitude of the OT
is close to -22.5, similar to the brightest super-luminous supernovae; however,
the lack of identifiable spectral features makes the massive stellar death
hypothesis less likely. A more plausible explanation appears to be the tidal
disruption of a sun-like star by the central super-massive black hole. We argue
that this transient likely belongs to a class of super-Eddington tidal
disruption events.
