Boyajian, Tabetha S. and McAlister, Harold A. and van Belle, Gerard and Gies, Douglas R. and ten Brummelaar, Theo A. and von Braun, Kaspar and Farrington, Chris and Goldfinger, P. J. and O'Brien, David and Parks, J. Roberts and Richardson, Noel D. and Ridgway, Stephen and Schaefer, Gail and Sturmann, Laszlo and Sturmann, Judit and Touhami, Yamina and Turner, Nils H. and White, Russel (2012) Stellar Diameters and Temperatures. I. Main-Sequence A, F, and G Stars. Astrophysical Journal, 746 (1). Art. No. 101. ISSN 0004-637X http://resolver.caltech.edu/CaltechAUTHORS:20120521-115008239
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We have executed a survey of nearby, main-sequence A-, F-, and G-type stars with the CHARA Array, successfully measuring the angular diameters of forty-four stars with an average precision of ~1.5%. We present new measures of the bolometric flux, which in turn leads to an empirical determination of the effective temperature for the stars observed. In addition, these CHARA-determined temperatures, radii, and luminosities are fit to Yonsei-Yale model isochrones to constrain the masses and ages of the stars. These results are compared to indirect estimates of these quantities obtained by collecting photometry of the stars and applying them to model atmospheres and evolutionary isochrones. We find that for most cases, the models overestimate the effective temperature by ~1.5%-4% when compared to our directly measured values. The overestimated temperatures and underestimated radii in these works appear to cause an additional offset in the star's surface gravity measurements, which consequently yield higher masses and younger ages, in particular for stars with masses greater than ~1.3 M_☉. Additionally, we compare our measurements to a large sample of eclipsing binary stars, and excellent agreement is seen within both data sets. Finally, we present temperature relations with respect to (B – V) and (V – K) colors as well as spectral type, showing that calibration of effective temperatures with errors ~1% is now possible from interferometric angular diameters of stars.
|Additional Information:||© 2012 American Astronomical Society. Received 2011 October 28; accepted 2011 December 14; published 2012 January 27. T.S.B. acknowledges support provided by NASA through Hubble Fellowship grant No. HST-HF-51252.01 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS 5-26555. The CHARA Array is funded by the National Science Foundation through NSF grant AST-0908253 and by Georgia State University through the College of Arts and Sciences. This research has made use of the SIMBAD literature database, operated at CDS, Strasbourg, France, and of NASA’s Astrophysics Data System. This publication makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by NASA and NSF.|
|Subject Keywords:||Hertzsprung-Russell and C-M diagrams; infrared: stars; stars: evolution; stars: fundamental parameters; stars: late-type; stars: solar-type; techniques: interferometric|
|Official Citation:||Stellar Diameters and Temperatures. I. Main-sequence A, F, and G Stars Tabetha S. Boyajian et al. 2012 ApJ 746 101|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Ruth Sustaita|
|Deposited On:||22 May 2012 15:09|
|Last Modified:||26 Dec 2012 15:14|
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