NOAO >   Observing Info >   Approved Programs >   2012A-0161

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Proposal Information for 2012A-0161


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

CoI: Andrzej Baran, Missouri State University
CoI: Simon O'Toole, Australian Astronomical Observatory
CoI: John Telting, Nordic Optical Telescope
CoI: Marcus Shadwick, Missouri State University
CoI: Roy Ostensen, KU Leuven

Title: Testing theoretical models of subdwarf B stars using multicolor photometry

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 subdwarfs B (sdB) stars, such identifications using white light photometry currently have significant limitations. We intend to use multicolor photometry to identify pulsation modes and constrain structure models. We propose to observe two pulsating sdB stars: PG1047+003 and PG1325+101. The first object will be observed as part of a multisite campaign (along with WHT and PROMPT). With multicolor photometry, we will use perturbative atmospheric models (BRUCE/KYLIE) 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. In January we have been allocated 7 night on the 2.1 m to collect multicolor data and on the 4 m for time-resolved spectroscopy on J06398+5156, another promising pulsating subdwarf B star for our purposes.


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 >   2012A-0161

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