A survey of hot subdwarf pulsators in ω Cen

Randal, S. K.; Calamida, A.; Fontaine, G.; Green, E. M.; Monelli, M.; Alonso, M. L.; Catelan, M.; Bono, G.; Dhillon, V. S.; Marsh, T. R.
Bibliographical reference

40th Liège International Astrophysical Colloquium. Ageing Low Mass Stars: From Red Giants to White Dwarfs, Liège, Belgium, Edited by J. Montalbán; A. Noels; V. Van Grootel; EPJ Web of Conferences, Volume 43, id.04006

Advertised on:
3
2013
Number of authors
10
IAC number of authors
1
Citations
2
Refereed citations
2
Description
We recently discovered an apparently new class of pulsating Extreme Horizontal Branch (EHB) star in ω Cen. Tightly clustered around ˜50,000 K, these H-rich sdO stars exhibit rapid, multi-periodic oscillations on a timescale of 100 s. While four such objects have been detected in ω Cen, no counterparts have yet been found among the field population. Conversely, the rapid sdB pulsators around 31,000 K that are well-studied in the Galactic field have yet to be found in a globular cluster. We discuss the implications of this and also report the discovery of a fifth EHB pulsator in ω Cen.