PI: Mukremin Kilic, Smithsonian Astrophysical Observatory (SAO), email@example.com
Address: SSP Division, 60 Garden Street, Cambridge, MA 02138, USA
CoI: Warren R. Brown, SAO
CoI: Scott Kenyon, SAO
Title: The Two Shortest Period Detached Binary White Dwarfs
Abstract: We recently discovered two record-breaking detached binary white dwarf systems. SDSS J0106 and LMWD 3 have orbital periods of 39.1 and 12.8 min, respectively, and radial velocity variations of 700 and 1600 km/s. Both systems will merge in only a few Myr due to gravitational wave radiation. LISA will detect LMWD 3 in the first week of operation; it is one of the strongest gravitational wave sources known. However, the amplitude of the gravitational wave strain and the outcome of the inevitable merger are uncertain due to the poorly constrained orbital parameters and secondary masses. The white dwarfs must be tidally distorted, so if we can measure their ellipsoidal variations (as detected for J0106) we can constrain their orbital inclinations. There is also a significant chance of eclipses. Thus we propose to use GMOS-N and GMOS-S to obtain time-resolved g- and r-band lightcurves, and Keck LRIS to obtain time-resolved spectroscopy of J0106 and LMWD 3. The GMOS data are critical to constrain orbital inclination and look for eclipses, relativistic beaming, and other effects. The Keck LRIS data are critical to resolve the radial velocity amplitudes and look for the spectroscopic signature of the companions. If the invisible companions are massive enough, these systems may be the progenitors of Type Ia or underluminous SNe.
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