[en] We recently discovered the first globular cluster hot subdwarf pulsators in Omega Centauri (ω Cen). These stars were initially thought to belong to the class of rapidly pulsating subdwarf B stars, which are well established among the field star population and have become showcases for asteroseismology. However, our spectroscopic analysis revealed the ω Cen variables to be significantly hotter than expected, indicating that they form a new class of subdwarf O pulsators clustered around 50 000 K, not known among the field star population. Non-adiabatic pulsation modelling suggests that the driver for the pulsations occurs via the same iron opacity mechanism that is at work in the rapidly pulsating subdwarf B stars.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Randall, S. K.; ESO) AB(Space Telescope Science Institute, Baltimore, USA) AC(Département de Physique, Université de Montréal, Canada) AD(Instituto de Astrofisica de Canarias, Tenerife, Spain) AE(Universita di Roma “Tor Vergata”, Department of Physics, Rome, Italy ; INAF – Osservatorio Astronomico di Roma, Monte Porzio Catone, Italy) AF(Pontificia Universidad Catolica de Chile, Santiago, Chile) AG(Institut d’Astrophysique et de Géophysique de l’Université de Liège, Belgium) AH(Département de Physique, Université de Montréal, Canada) AI(Space Telescope Science Institute, Baltimore, USA) AJ(Pontificia Universidad Catolica de Chile, Santiago, Chile) AK(Department of Physics and Astronomy, University of Sheffield, United Kingdom) AL(Department of Physics and Astronomy, University of Sheffield, United Kingdom ; Instituto de Astrofisica de Canarias, Tenerife, Spain) AM(Department of Physics, University of Warwick, Coventry, United Kingdom)
Calamida, A.
Fontaine, G.
Monelli, M.
Bono, G.
Alonso, M. L.
Van Grootel, Valérie ; Université de Liège > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique stellaire théorique et astérosismologie
