Period changes in the pulsating extreme helium stars V652 Her and BX Cir

Thirty-four new timings of maxima of the radially pulsating extreme helium (EHe) star V652 Her (= BD+13° 3224) obtained during 1996–2004 are reported. The quartic ephemeris (for the pulsation period decrease) is extended and the higher-order terms are defined more accurately. We also report 45 new t...

Full description

Saved in:
Bibliographic Details
Published in:Monthly notices of the Royal Astronomical Society 2005-08, Vol.361 (2), p.559-564
Main Authors: Kilkenny, D., Crause, L. A., van Wyk, F.
Format: Article
Language:English
Subjects:
Astronomical research
Helium
Stars & galaxies
stars: chemically peculiar
stars: individual: BX Cir
stars: individual: V652 Her
stars: oscillations
stars: variables: other
Time
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Thirty-four new timings of maxima of the radially pulsating extreme helium (EHe) star V652 Her (= BD+13° 3224) obtained during 1996–2004 are reported. The quartic ephemeris (for the pulsation period decrease) is extended and the higher-order terms are defined more accurately. We also report 45 new timings of maxima for the closely similar star BX Cir (= LSS 3184) over the same baseline and present the first evidence that this star also shows a decreasing period. The data obtained thus far can be represented by a quadratic ephemeris — a linearly decreasing period in BX Cir — though the decrease rate (dP/dn| 3.7 × 10-10 d) is much smaller than in V652 Her.
ISSN:0035-8711
1365-2966
DOI:10.1111/j.1365-2966.2005.09188.x