NOAO >   Observing Info >   Approved Programs >   2005A-0017

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Proposal Information for 2005A-0017


PI: Mercedes Lopez-Morales, Carnegie Institution of Washington, mercedes@dtm.ciw.edu
Address: Department of Terrestrial Magnetism, 5241 Broad Branch Rd. NW, Washington, DC 20015, USA

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

Title: First RV-curve of the new low-mass, double-lined, detached eclipsing binary ASAS164755-0844.5

Abstract: Until 2002 the theoretical mass-radius relation of stars < 1M_\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 find radii 10-20% larger than the ones predicted by any of the current models; however, the current amount of data is still insufficient to confirm or discard this trend. We ask for 2 nights at the KPNO 4m to obtain radial velocity curves of a fifth binary, ASAS164755. The new system (V~ 13.0; P=0.503264 days) has an estimated total mass M_1+M_2 <=1.3M_\odot and L_2/L_1$~eq 0.76. These RV-curves will be combined with VRI light curves to derive masses and radii of the system with errors < 2%. The new masses and radii will increase by 25% the data available to date, and will serve as additional tests to the current models.


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NOAO >   Observing Info >   Approved Programs >   2005A-0017

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