EDP Sciences
Free Access
Issue
A&A
Volume 393, Number 2, October II 2002
Page(s) 563 - 571
Section Formation, structure and evolution of stars
DOI https://doi.org/10.1051/0004-6361:20021085


A&A 393, 563-571 (2002)
DOI: 10.1051/0004-6361:20021085

Velocity variability of semiregular and irregular variables

T. Lebzelter1 and K. H. Hinkle2

1  Institut für Astronomie, Universität Wien, Türkenschanzstr. 17, 1180 Vienna, Austria
2  National Optical Astronomy Observatory (Operated by the Association of Universities for Research in Astronomy, Inc. under cooperative agreement with the National Science Foundation.) , 950 N. Cherry Avenue, PO Box 26732, Tucson, Arizona 85726, USA

(Received 17 April 2002 / Accepted 11 July 2002 )

Abstract
We compare velocities from near infrared lines with center-of-mass velocities for a sample of semiregular and irregular variables to search for indications for a convective blueshift. It is shown that a general blueshift is present but that the light variability is obviously not dominated by convective cells but rather by stellar pulsation. All stars of our sample show a similar shape and amplitude in the velocity variations. Long secondary periods are a common feature in these objects and strongly influence the measured velocity shifts. The star V366 Aql is found to be the first SRV showing line doubling.


Key words: stars: variables: general -- stars: late-type -- stars: AGB and post-AGB -- stars: atmospheres

Offprint request: T. Lebzelter, lebzelter@astro.univie.ac.at

SIMBAD Objects



© ESO 2002

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.