PI: Paul Canton, University of Oklahoma, Paul.Canton@ou.edu
Address: Department of Physics and Astronomy, 440 W. Brooks St., Norman, OK 73019, USA
CoI: Mukremin Kilic, University of Oklahoma
CoI: Warren Brown, Smithsonian Astrophysical Observatory
CoI: Scott Kenyon, Smithsonian Astrophysical Observatory
Title: The ELM Survey: Finding the Shortest Period Binary White Dwarfs
Abstract: A new discovery space for short period binary white dwarfs has opened up with the availability of 14,600 deg^2 of SDSS Data Release 9 photometry. The Extremely Low-Mass (ELM) Survey takes advantage of this photometry and SDSS spectroscopy to identify compact systems with 1 hour or shorter orbital periods. To significantly increase the number of merging white dwarf systems known, we propose to obtain follow-up spectroscopic observations of all candidates with g \le 19 mag and photometric colors consistent with extremely low-mass (<=0.3 M_\odot) white dwarfs. We were granted 4 nights on the Hale 5m in April 2012 and 4 nights on the KP 4m in December 2012. Most of our Hale observing run was lost to humidity and clouds, yet we managed to identify at least one new short period binary. Here we propose to continue our program by observing our remaining spring targets on the KPNO 4m telescope. Our two major science goals are to discover detached gravitational wave sources for fundamental tests of general relativity, and to constrain the formation rate and space density of merging white dwarfs. The latter is important for constraining the contribution of double degenerates to Type Ia and underluminous supernovae.
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