NOAO >   Observing Info >   Approved Programs >   2015B-0074

# Program Information for 2015B-0074

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 USA

CoI: Matthew Burleigh, University of Leicester
CoI: Ian Braker, University of Leicester
CoI: Katherine Lawrie, University of Leicester

Title: Spectroscopic characterisation of Kepler 2 White Dwarfs

Abstract: Up to 50\% of the $\approx25$ White Dwarfs in the Kepler and Kepler 2 (K2) campaign 0 fields show low level periodic variability, from a few hundred ppm to $\pm5$\%. Ground-based observations have 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 behaviour may be due to the accretion of metal rich material, or the presence of an ultra-low mass companion. 100s of WDs will be observed in the K2 fields, but many have only been identified through photometry. Spectroscopic observations are required to characterise these WDs: to determine their temperatures, gravities, masses, radii, dominant chemical composition, and to search for evidence of magnetism or metals in their atmospheres, in order to understand the sources of the variability being revealed by K2.

Program Type: Standard/Galactic

Scheduled Nights:
Run 1 (2015B):  KP-4m/KOSMOS -- 3n on Dec 18 - Dec 20 2015

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 >   2015B-0074