The domain of ? Doradus variables in the Hertzsprung-Russell diagram

Author(s)
Gerald Handler
Abstract

70 new ? Doradus candidates were identified from Hipparcos photometry, which represents more than a doubling of the presently known number. Selecting the objects with good evidence for multiperiodicity, it is found that these stars, together with bona fide members of the class, occupy a well-defined region in a colour-magnitude diagram. This domain corresponds to a range of 7200-7700 K on the zero-age main sequence (ZAMS) and 6900-7500 K one magnitude above it, which partly overlaps with the instability strip of d Scuti stars. For the first time, ? Doradus stars can be discussed as a group. They can be found over a significant fraction of the main sequence lifetimes for objects in the relevant temperature range. An upper limit on the surface metallicity of ? Doradus stars is apparent, which may guide the search for their pulsation driving mechanism. The importance of possible objects exhibiting both ? Doradus and d Scuti-type pulsations is discussed.

Organisation(s)
Department of Astrophysics
Journal
Monthly Notices of the Royal Astronomical Society
Volume
309
ISSN
0035-8711
Publication date
1999
Peer reviewed
Yes
Austrian Fields of Science 2012
103003 Astronomy
Portal url
https://ucrisportal.univie.ac.at/en/publications/the-domain-of--doradus-variables-in-the-hertzsprungrussell-diagram(1449036b-914a-46f4-919d-36b0d70e33fe).html