NOAO >   Observing Info >   Approved Programs >   2006A-0205

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Proposal Information for 2006A-0205


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

CoI: Stacey Harms, Missouri State University
CoI: Simon O'Toole, Anglo-Australian Observatory
CoI: Stacey Harms, Missouri State University

Title: Time series spectrosctopy of the pulsating subdwarf B star PG1219+534

Abstract: Pulsating stars allow a direct investigation of their structure and therefore of their evolutionary history, from the evaluation of the pulsation modes. However, the pulsation modes must first be identified with spherical harmonics. For subdwarf B (sdB) stars, such identifications have proven difficult. To solve this problem, we intend to use time series spectroscopy (with optical photometry) to determine the spherical harmonics. We propose multi-site spectroscopic and photometric observations to accurately measure pulsation velocity, line profile variations, and changes in temperature and gravity due to pulsations of the pulsating sdB star PG1219+534. (This proposal was granted in 2005, but because of weather and telescope failure, only obtained 1.5 hours of data.) Once modes are identified, the powerful tools of asteroseismology can be applied to derive stellar parameters such as total mass, envelope mass, composition discontinuities, and rotation rate.


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NOAO >   Observing Info >   Approved Programs >   2006A-0205

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