NOAO >   Observing Info >   Approved Programs >   2018A-0110

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Program Information for 2018A-0110


PI: Paul Wilson Cauley, Arizona State U., pwcauley@gmail.com
Address: Department of Physics and Astronomy, Box 871504, Tempe, AZ, 85287-1504 USA

CoI: Jay Farihi, University College London
CoI: Seth Redfield, Wesleyan U.

Title: Testing the eccentric ring model for circumstellar absorption around WD1145+017

Abstract: Polluted white dwarfs offer a unique window into the elemental abundances of rocky bodies that have survived the post-main sequence evolution of their host stars. The polluted white dwarf WD1145+017 was recently discovered to exhibit a large variety of white-light transits, suggesting the presence of small rocky bodies orbiting near the star's Roche limit. This system also has strong circumstellar absorption lines in a variety of metals throughout the optical spectrum. Our group has monitored these circumstellar features over the last 2.2 years and a gradual shift in the absorption velocities, from strongly red-sfhited to strongly blue-shifted, has been observed. We have developed an eccentric gas ring model to explain the absorption velocities seen in the circumstellar lines. The evolution of the line profiles is mostly explained by the precession of these rings according to timescales given by general relativity. Here we propose a long-term monitoring program of WD1145+017 in order to test our model of the circumstellar absorption and gain insight into the structure and dynamics of the gas in this unique system.

Program Type: Standard/Galactic

Scheduled Nights:
Run 1 (2018A):  GEM-N-SVC/GRACES -- 4.5hrs band 1 (GN-2018A-Q-126 )


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 >   2018A-0110

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