NOAO > Observing Info > Approved Programs > 2013A-0491
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NOAO > Observing Info > Approved Programs > 2013A-0491 |
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PI: Mike Reed, Missouri State University, mikereed@missouristate.edu
Address: Physics Department, 901 S. National, Springfield, MO 65897, USA
CoI: Andrzej Baran, Missouri State University
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 the pulsating sdB stars PG1325+101 (QQ Vir).
We were allocated time during 2012A, but because of inclement weather,
we (successfully) observed a back-up target instead. Our updated
instrument has a wider FoV, which will allow additional comparison stars
and therefore we would be able to use non-photometric conditions. 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. We
have had four runs at KPNO during 2012 and our data measure amplitude
differences between filters. Our collaborators are producing
atmospheric models and we expect publications early in 2013.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360
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NOAO > Observing Info > Approved Programs > 2013A-0491 |
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