Bibcode
Vladilo, G.; Molaro, P.; Crivellari, L.; Foing, B. H.; Beckman, J. E.; Genova, R.
Bibliographical reference
Astronomy and Astrophysics (ISSN 0004-6361), vol. 185, no. 1-2, Oct. 1987, p. 233-246. CNR-supported research.
Advertised on:
10
1987
Citations
38
Refereed citations
34
Description
The authors have used high resolution IUE spectra from their own studies
and from the archive to examine the Mg II h and k chromospheric emission
cores of a sample of late-type dwarfs and giants. Sharp photospheric
absorptions were used to provide a velocity rest-frame with respect to
each stellar photosphere with the IUE-limited precision of ±4 km
s-1. The knowledge of the kinematics of the local
interstellar medium (LISM) could then be used to identify cases where
either the cores or the wings, or in best circumstances both features of
the chromospheric lines were uncontaminated by LISM absorption. The
authors derive, using only LISM-free emission wings, accurate
Wilson-Bappu relations for both the h and k line, characterized by a
slope higher than in previous determinations.