Semiregular variables of types SRa and SRb - Basic properties in the visual and the IRAS-range

Autor(en)

Franz Kerschbaum, Josef Hron

Abstrakt

The pulsational properties, T(eff)s, mass loss rates, luminosities, scale heights, and volume densities in the Galactic plane are presented for samples of optical semiregular variables of types SRa and SRb correlated with the IRAS point source catalog. These properties are compared to the corresponding characteristics of optical Mira variables. It is found that the SRa's are not a distinct class of variables but a mixture of 'intrinsic' Miras and SRb's. The O-rich SRb's form a quite homogeneous group in terms of periods, amplitudes, and temperatures. They consist of a 'blue' group with no indication of circumstellar shells, with P less than 150 d and T(eff) greater than 3200 K, and a 'red' group with temperatures and mass loss rates comparable to Miras but periods about a factor of two smaller. The C-rich SRVs generally have smaller periods and are more abundant than C-rich Miras. The evolutionary status of the SRVs is discussed.

Organisation(en)

Institut für Astrophysik

Journal

Astronomy & Astrophysics

Band

263

Seiten

97 - 112

Anzahl der Seiten

16

ISSN

0004-6361

Publikationsdatum

09-1992

Peer-reviewed

Ja

ÖFOS 2012

103003 Astronomie, 103004 Astrophysik

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/semiregular-variables-of-types-sra-and-srb--basic-properties-in-the-visual-and-the-irasrange(1594da36-3589-4b91-8d93-60cfc0cc881c).html