UVCS has observed several dozen stars between 1996 and 2001, most
of which were used as calibration transfer standards and flat-field
sources.  UVCS has the advantage of being able to observe both bright
and relatively faint stars close to the Sun.  This image is a
false-color image of the count rates on one of the UVCS detectors
when the hot star rho Leo was passing through the entrance slit.
The vertical axis is spatial distance along the slit (which is
oriented transversely to the solar radial direction) and the
horizontal axis is the spectral dispersion direction; i.e., the
wavelength direction.  The background corona is visible in its
strong emission lines of O VI and the H I Lyman lines.  The stellar
spectrum, which has a strong continuum in addition to many
absorption and emission lines, is observable as a narrow horizontal
strip at the spatial location where the star image passed through
the spectrometer slit.