NOAO >   Observing Info >   Approved Programs >   2017B-0184

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Program Information for 2017B-0184


PI: Jay Holberg, U. of Arizona, holberg@lpl.arizona.edu
Address: Lunar & Planetary Laboratory, Kuiper Space Sci, Bldg 92 1629 E Univ Blvd, Tucson, Arizona AZ 85721-0092

CoI: Matthew Burleigh, University of Leicester
CoI: Ian Braker, University of Leicester
CoI: Claudia Belardi, University of Leicester

Title: Spectroscopic characterisation of Kepler 2 White Dwarfs

Abstract: Up to 50% of the $approx$25 White Dwarfs in the Kepler and Kepler 2 (K2) campaign 0 fields show low level periodic variability, from a few hundred ppm to $pm$5%. Ground-based observations have previously shown that 30-40% of magnetic WDs display variability on their rotation periods, due to star spots or magnetic dichroism, but the modulations observed in the mainly non-magnetic Kepler / K2 WDs cannot all be explained by such mechanisms. Alternatively, this behavior may be due to the accretion of metal rich material, or the presence of an ultra-low mass companion. 100s of WDs are being observed in the K2 fields. Many are poorly studied, and have only been identified through photometry. In order to understand the sources of the variability being revealed by K2, spectroscopic observations are now required to characterize these stars: to determine their temperatures, gravities, masses, radii, dominant chemical composition, and to search for evidence of magnetism or the presence of metals in their atmospheres.

Program Type: Standard/Galactic

Scheduled Nights:
Run 1 (2017B):  KP-4m/KOSMOS -- 3n on Oct 13 - Oct 15 2017


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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