2006/01/23 by A. Kawka, Adela Kawka, Stephane Vennes +1 · 5 citations
Chemistry · Physics and Astronomy · #Astro and Planetary Science #Astronomy and Astrophysical Research #Astrophysics #Chemistry #Photometry (optics) #Physics #Population #Stars #Stellar, planetary, and galactic studies #White (mutation) #White dwarf #astro-ph
paper · pdf · doi:10.1086/501451
published as Astrophys.J. 643 (2006) 402-415 · Accepted for publication in ApJ, fixed typo in text
arxiv created 2006/01/23 · openalex publication_date 2006/05/18 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The New Luyten Two-Tenths catalog contains a large number of high proper motion white dwarf candidates that remain to be spectroscopically confirmed. We present new spectroscopic observations, as well as SDSS archival spectra of 49 white dwarf candidates selected from the revised NLTT catalog of Salim & Gould. Of these, 34 are cool DA white dwarfs with temperatures ranging from approximately 5000 up to 11,690 K, and 11 are DC white dwarfs with temperatures ranging from 4300 K (NLTT 18555) up to 11,000 K. Three of the DA white dwarfs also display abundances of heavy elements (NLTT 3915, NLTT 44986, and NLTT 43806), and one is a cool magnetic white dwarf (NLTT 44447) with an estimated magnetic field strength of 1.3 MG. We also present a new cool DQ white dwarf (NLTT 31347) with an estimated temperature of 6250 K. We supplement our sample with SDSS ugriz photometry for a fraction of the newly identified white dwarfs. A kinematical study of this sample of white dwarfs, characterized by proper motions ranging from 0 136 to 0 611 yr -1 , suggest that they belong to the thin disk population.