A search for rapid oscillations in chemically peculiar A-type stars

Autor(en)

Gerald Handler, Ernst Paunzen

Abstrakt

In 1995 we initiated a Northern Hemisphere survey for rapidly oscillating Ap stars. This paper presents the results including one new roAp star (HD 122970), the confirmation of rapid oscillations of HD 99563 and apparent null results for other stars. Using Hipparcos data a statistical analysis of the absolute magnitudes and galactic distributions of all known roAp and noAp stars (also taken from the literature) was made. A systematic trend for most of the program stars in a MV vs. β (index of the Strömgren uvbyβ system) diagram was detected leading to the conclusion that β is systematically influenced by the chemical peculiarity and/or magnetic field. Three roAp stars are outside the δ Scuti instability strip which implies that the driving mechanism of the two classes of pulsating star is different. This is also suggested by new pulsation models. No statistical difference between the galactic distribution of roAp and noAp stars was found.

Organisation(en)

Institut für Astrophysik

Journal

Astronomy & Astrophysics Supplement Series

Band

135

Seiten

57-63

Anzahl der Seiten

7

ISSN

0365-0138

Publikationsdatum

1999

Peer-reviewed

Ja

ÖFOS 2012

103003 Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/a7506906-0e68-47c5-9a75-0ed3a7ba9fe4