Discovery of New Ultracool White Dwarfs in the Sloan Digital Sky Survey

2004/05/28 by Evalyn Gates, Geza Gyuk, Hugh C. Harris +14 · 63 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Blue dwarf #Brown dwarf #Sky #Stellar classification #Stellar, planetary, and galactic studies #White (mutation) #White dwarf #astro-ph

paper · pdf · doi:10.1086/424568

published in The Astrophysical Journal 612(2), L129-L132 (IOP Publishing) · 15 pages, 3 figures, submitted to ApJL. Higher resolution versions of finding charts are available at http://astro.uchicago.edu/~gates/findingcharts

arxiv created 2004/05/28 · openalex publication_date 2004/08/12 · arxiv updated 2012/08/27 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

We report the discovery of five new white dwarfs in the Sloan Digital Sky Survey. Four are ultracool, exhibiting strong collision-induced absorption (CIA) from molecular hydrogen and are similar in color to the three previously known coolest white dwarfs, SDSS J1337+00, LHS 3250, and LHS 1402. The fifth star shows milder CIA flux suppression and has a color and spectral shape similar to WD 0346+246. All five new white dwarfs are faint ( g > 18.9) and have significant proper motions. One of the new ultracool white dwarfs, SDSS J0947, appears to be in a binary system with a slightly warmer ( T eff ~ 5000 K) white dwarf companion.

Citations

• The Sloan Digital Sky Survey Photometric Camera
• Radiative Transfer in the Refractive Atmospheres of Very Cool White Dwarfs
• A Photometricity and Extinction Monitor at the Apache Point Observatory
• A Very Low Luminosity, Very Cool, DC White Dwarf
• Model Atmosphere Analysis of Two Very Cool White Dwarfs

Cited by

• Fifteen new T dwarfs discovered in the UKIDSS Large Area Survey
• A DETAILED MODEL ATMOSPHERE ANALYSIS OF COOL WHITE DWARFS IN THE SLOAN DIGITAL SKY SURVEY