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Title: THE SOLAR NEIGHBORHOOD. XXI. PARALLAX RESULTS FROM THE CTIOPI 0.9 m PROGRAM: 20 NEW MEMBERS OF THE 25 PARSEC WHITE DWARF SAMPLE

Journal Article · · Astronomical Journal (New York, N.Y. Online)
; ;  [1];  [2];  [3];  [4];
  1. Department of Physics and Astronomy, Georgia State University, Atlanta, GA, 30302-4106 (United States)
  2. Departement de Physique, Universite de Montreal, C.P. 6128, Succ. Centre-Ville, Montreal, Quebec H3C 3J7 (Canada)
  3. Department of Astronomy and Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)
  4. Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States)

We present accurate trigonometric parallaxes for 20 new members of the 25 pc white dwarf (WD) sample as part of the Discovery and Evalution of Nearby Stellar Embers (DENSE) project.{sup 7} http://www.DenseProject.com Previously, there were a total of 112 WD systems with trigonometric parallaxes placing them within 25 pc and of these, 99 have trigonometric parallaxes known to better than 10%. Thus, the 20 new members presented in this work represent a 20% increase in the number of WDs accurately known to be within 25 pc. In addition, we present updated parallaxes for seven known WDs within 10 pc that have been observed as part of the Astrometric Search for Planets Encircling Nearby Stars initiative to monitor nearby southern red dwarfs and WDs for astrometric perturbations from unseen companions. Including a few WD companions and WDs beyond 25 pc, we present a total of 33 trigonometric parallaxes. We perform atmospheric modeling for WDs to determine physical parameters (i.e., T {sub eff}, log g, mass, and WD age). Finally, a new ZZ Ceti pulsating WD was identified and revised constraints are placed on two mixed H/He atmosphere cool WDs that display continuum absorption in the near-infrared.

OSTI ID:
21255768
Journal Information:
Astronomical Journal (New York, N.Y. Online), Vol. 137, Issue 6; Other Information: DOI: 10.1088/0004-6256/137/6/4547; Country of input: International Atomic Energy Agency (IAEA); ISSN 1538-3881
Country of Publication:
United States
Language:
English