NOAO >   Observing Info >   Approved Programs >   2011B-0358

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Proposal Information for 2011B-0358


PI: Mike Reed, Missouri State University, mreed@sdbv.missouristate.edu
Address: Physics Department, 901 S. National, Springfield, MO 65897, USA

CoI: Andrzej Baran, Pedagogical University of Krakow
CoI: Simon O'Toole, Australian Astronomical Observatory
CoI: Laurel Farris, Missouri State University

Title: Testing subdwarf B stellar models using multicolor photometry and time- resolved spectroscopy

Abstract: Pulsating stars allow a direct investigation of their structure and evolutionary history from the evaluation of pulsation modes. However, the observed pulsation frequencies must first be identified with spherical harmonics (modes). For subdwarf B (sdB) stars, such identifications using white-light photometry currently have significant limitations. We propose using multicolor photometry combined with time- resolved spectroscopy to identify pulsation modes and constrain structure models. We propose to observe J06398+5156 a newly discovered, bright, high amplitude and hybrid subdwarf B pulsator. We will measure radial velocity, effective temperature, and gravity variations produced by the pulsations. With simultaneous multicolor photometry, we will use perturbative atmospheric models to identify the pulsation frequencies. This is part of our NSF grant to obtain seismic tools to test structure and evolution models, constraining stellar parameters including total mass, envelope mass, internal composition discontinuities, and internal rotation.


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



NOAO >   Observing Info >   Approved Programs >   2011B-0358

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