Pulsation Period Variation in the Subdwarf B Star EC 20117-4014

S.K. Randall1,2, I.P. Lopes3 and A.E. Lynas-Gray3
1 University College London, Department of Physics and Astronomy, Gower Street, London WC1E 6BT, England
2 Université de Montréal, Département de Physique, C.P. 6128 succursale centre-ville, Montréal, Québec H3C 3J7, Canada
3 University of Oxford, Astrophysics, Keble Road, Oxford OX1 3RH, England

 

Since the discovery of pulsations in the Subdwarf B (SdB) star EC 20117-4014, variations in the pulsation periods have not been understood, they could for example be attributable to the SdB star's motion about the barycentre of the binary system in which it resides.
Six nights of high speed photometry obtained in July 2001 led to the detection of several new pulsation frequencies in addition to the three known previously. It was also discovered that the pulsations' amplitudes, phases and periods showed significant night-to-night variations.
The nature of these variations will be further explored following an observing run scheduled for July 2002.

 
Print this abstract