Asteroseismology of the Nearby SN-II Progenitor: Rigel Part I. The MOST High Precision Photometry and Radial Velocity Monitoring

Ehsan Moravveji, Edward F. Guinan, Matt Shultz, Michael H. Williamson, Andres Moya

1- Department of Physics, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran
2- Department of Astronomy, Villanova University, 800 Lancaster Ave, Villanova, PA 19085, USA
3- Royal Military College of Canada, PO Box 17000, Station Forces, Kingston, ON K7K 4B4, Canada
4- Center of Excellence in Information Systems, Tennessee State University, Nashville, USA
5- Departamento de Astrof'{i}sica, Centro de Astrobiolog'ia (INTA-CSIC), PO BOX 78, 28691
Villanueva de la Ca~nada, Madrid, Spain

Rigel (beta Ori, B8 Ia) is a nearby blue supergiant displaying alpha Cyg type variability, and is one of the nearest type-II supernova progenitors. As such it is an excellent test bed to study the internal structure of pre core-collapse stars. In this study, for the first time, we present 28 days of high precision MOST photometry and over 6 years of spectroscopic monitoring. We report nineteen significant pulsation modes of SNR>4.6 from radial velocities, with variability time scales ranging from 1.21 to 74.7 days, which are associated with high order low degree gravity modes. While the radial velocity variations show a degree of correlation with the flux changes, there is no clear interplay between the equivalent widths of different metallic and Halpha lines.

Reference: ApJ, 745 (in press)
Status: Manuscript has been accepted