Skip to main content

Rapid dynamic processes in Ap star atmospheres

Buy Article:

$63.00 plus tax (Refund Policy)


Long-term observations with short exposures in 1999-2001 allowed us to reveal the rapid variation in light velocities and equivalent widths of various spectral lines in the spectra of Ap stars χ Psc and γ Equ with pulsation periods 17 min and 12 min respectively. To determine the pulsation periods more precisely, a frequency analysis has been applied. Our observations show that, apart from the variability related to an axial rotation of the star, two more types of variability in an observable group of stars have been detected: firstly, short-term oscillations with 12-17 min periods; secondly, a relatively slow variability with 1.5-2.5 h characteristic times. The short-term spectrum variability is shown to be observed for all programmed stars, but only χ Psc and γ Equ spectra variations are periodic. The second, a slower type of spectrum variability (1.5-3 h), is also reliably observed for χ Psc and γ Equ stars. According to the observed spectral characteristics, the star θ Aur may be referred to a subgroup of roAp stars.

Keywords: Ap stars; Spectral observations; Variability

Document Type: Research Article


Publication date: 2003-08-01

More about this publication?
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more