We have secured high spatial and temporal resolution spectra of the rapidly
rotating K-dwarf, SPEEDY (HD 197890) at two sites and a common epoch
of observations. The 0.38 d axial rotation period and the V band magnitude
of 9.33 make it a difficult target for Doppler imaging. In order to obtain high
S/N ratio profiles from 300 secs exposures, we apply the technique of least
squares deconvolution to the large number of photospheric absorption lines
available in each of our spectra. This allows us to derive high resolution
maximum entropy regularised Doppler images of the stellar surface. Using
these techniques, we also derive radial velocities and accurate projected
equatorial rotation velocities which are consistent to within about 1 km/s.
Our surface maps reveal one of the most heavily spotted photospheres seen
on a rapid rotator, with starspots occurring at all latitudes. At the time of
observations, SPEEDY had no strong polar spot, but shows spots concentrated
in low and intermediate latitude bands. We attempt a differential rotation
measurement, but lack of sufficient phase coverage only allows determination
of a lower limit of 59 days for the time it takes the equatorial regions
to lap the polar regions.
We also find variations in the heavily filled in Halpha line which can be
attributed to prominences passing in front of the stellar disc. Despite the rapid
rotation, the appearance of the same features between consecutive nights of
observations shows the clouds to be stable on timescales of at least a day.