NOAO > Observing Info > Approved Programs > 2011B-0009
|
NOAO > Observing Info > Approved Programs > 2011B-0009 |
|
PI: Mukremin Kilic, Smithsonian Astrophysical Observatory (SAO), mkilic@cfa.harvard.edu
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.
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 > 2011B-0009 |
|