NOAO >   Observing Info >   Approved Programs >   2005B-0137

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Proposal Information for 2005B-0137


PI: Mercedes Lopez-Morales, Carnegie Institution of Washington, mercedes@dtm.ciw.edu
Address: Department of Terrestrial Magnetism, 5241 Broad Branch Rd. NW, Washington, DC 20008, USA

CoI: J. Scott Shaw, Univ. of Georgia at Athens, USA
CoI: Ignasi Ribas, IEEC, Spain

Title: RV-curves of six new double-lined, detached eclipsing binaries with masses below 1Msun.

Abstract: Until 2003 the theoretical mass-radius relation of stars < 1 M_sun was constrained by only four direct observations from the eclipsing binaries CM Dra and YY Gem. Two new binaries, CU Cnc and GU Boo, have provided four new data points since then. All the observations to date find radii 10-15 % larger than the ones predicted by any of the current models. However, the current amount of data is still insufficient to confirm or discard that trend. We ask for a total of 12 nights at the KPNO 4m to obtain radial velocity (RV) curves of six new low-mass eclipsing binaries. The new systems have apparent magnitudes between V=13.1 and 14.2, orbital periods between P=0.36697 and 1.53837 days, and stellar masses between 0.35 and 1.0 M_sun. These RV curves will be combined with VRI and JHK light curves to derive stellar masses and radii with errors < 2-3 %. The new masses and radii will double the data available to date. The results of this work, added to the existing data, will provide for the first time an statistically significant sample of accurate masses and radii to test current models of very low-mass stars.


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NOAO >   Observing Info >   Approved Programs >   2005B-0137

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