DOPPLER IMAGING OF STELLAR SURFACE-STRUCTURE .3. THE X-RAY SOURCE HD-116544 EQUALS IN VIRGINIS

We present the first Doppler image of the EXOSAT X-ray source EXO 1321 .8-0203, recently identified to be a chromospherically active star exh ibiting periodic light variations and consequently named IN Virginis. Our high-resolution spectra show IN Virginis to be a single-lined spec troscopic binary with an orbital period of 8.2 days, very strong Call emission, and an inverse P-Cygni type H alpha line profile. A detailed spectrum synthesis yields a photospheric temperature of 4600 +/- 70 K and log g = 3.5 - 4.0 and slight overabundance of the heavy elements but otherwise solar abundances. We redetermine the photometric period from a new set of photometry obtained with a robotic photoelectric tel escope in the years 1994 and 1995 and conclude that IN Virginis is mor e likely a K2-3 subgiant instead of a K5 dwarf or K4 subgiant as previ ously published. The Doppler images from March 1994 show a cool polar spot that is dominated by a large appendage reaching a latitude of +40 degrees. Its average temperature difference, photosphere minus polar spot, is 1000 K. Additionally, three equatorial spots are clearly reco vered but have Delta T approximate to 400 K. Possibly, we also detecte d a warm equatorial feature with Delta T approximate to-150 K. We emph asize that Doppler imaging of IN Virginis is very challenging because of both the small v sin i of the star (24.0 km s(-1)) and its relative ly cool photosphere causing many weak absorption-line blends. Still, m aps from the different lines appear encouragingly similar.