Forum Springer Astron. Astrophys.
Forum Whats New Search Orders

Astron. Astrophys. 319, 535-546 (1997)

Next Section Table of Contents

Doppler imaging of stellar surface structure

III. The X-ray source HD 116544 = IN Virginis

K.G. Strassmeier *

Institut für Astronomie, Universität Wien, Türkenschanzstraße 17, A-1180 Wien, Austria (strassmeier@astro.ast.univie.ac.at)

Received 17 June 1996 / Accepted 30 July 1996


We present the first Doppler image of the EXOSAT X-ray source EXO 1321.8-0203, recently identified to be a chromospherically active star exhibiting periodic light variations and consequently named IN Virginis. Our high-resolution spectra show IN Virginis to be a single-lined spectroscopic binary with an orbital period of 8.2 days, very strong Ca II emission, and an inverse P-Cygni type H [FORMULA] line profile. A detailed spectrum synthesis yields a photospheric temperature of 4600 [FORMULA] 70 K and [FORMULA] 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 telescope in the years 1994 and 1995 and conclude that IN Virginis is more likely a K2-3 subgiant instead of a K5 dwarf or K4 subgiant as previously published.

The Doppler images from March 1994 show a cool polar spot that is dominated by a large appendage reaching a latitude of [FORMULA]. Its average temperature difference, photosphere minus polar spot, is 1000 K. Additionally, three equatorial spots are clearly recovered but have [FORMULA] 400 K. Possibly, we also detected a warm equatorial feature with [FORMULA] -150 K. We emphasize that Doppler imaging of IN Virginis is very challenging because of both the small [FORMULA] of the star (24.0 km s-1) and its relatively cool photosphere causing many weak absorption-line blends. Still, maps from the different lines appear encouragingly similar.

Key words: stars: activity of – stars: imaging – stars: individual: IN Vir – stars: late-type – stars: fundamental data

* Visiting Astronomer, Kitt Peak National Observatory, operated by the Association of Universities for Research in Astronomy, Inc. under contract with the National Science Foundation

SIMBAD Objects


Next Section Table of Contents

© European Southern Observatory (ESO) 1997

Online publication: July 3, 1998