2002/07/31 by P. Bergeron, S. K. Leggett · 3 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Atmosphere (unit) #Context (archaeology) #Energy distribution #Hydrogen #Infrared #Stars #Stellar atmosphere #Stellar, planetary, and galactic studies #White dwarf #astro-ph
paper · pdf · doi:10.1086/343795
published as Astrophys.J.580:1070-1076,2002 · Accepted for publication in the Astrophysical Journal; 14 pages 9 figures
arxiv created 2002/07/31 · openalex publication_date 2002/12/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
A detailed analysis of the very cool white dwarfs SDSS 1337+00 and LHS 3250 is presented. Model atmosphere calculations with improved collision-induced absorptions by molecular hydrogen indicate that a pure hydrogen composition can be ruled out and that the strong infrared absorption observed in these cool stars is better explained in terms of collisions of H 2 with neutral helium. It is shown that even though the overall shape of the observed energy distributions can be reproduced reasonably well with helium-rich models, the peak of the energy distribution near 6000 Å is always predicted too narrow. The extreme helium-rich composition inferred for both objects is discussed in the broader context of the extremely cool white dwarfs reported in various surveys.