2016/10/18 by Ingrid Pelisoli, Pelisoli, Ingrid, S. O. Kepler +5 · 1 citation
Physics and Astronomy · #85-06 #Astronomy and Astrophysical Research #FOS: Physical sciences #Pulsars and Gravitational Waves Research #Solar and Stellar Astrophysics (astro-ph.SR) #Stellar, planetary, and galactic studies #astro-ph.SR #msc:85-06
paper · pdf · doi:10.48550/arxiv.1610.05550
6 pages, 3 figures. To appear in the ASP Conference Series proceedings of "20th European Workshop on White Dwarfs," held at the University of Warwick, UK on July 25-29th, 2016
arxiv created 2016/10/18 · openalex publication_date 2016/10/18 · arxiv updated 2016/10/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
White dwarfs with log g lower than 7.0 are called Extremely Low Mass white dwarfs (ELMs). They were first found as companions to pulsars, then to other white dwarfs and main sequence stars (The ELM Survey: 2010 to 2016), and can only be formed in interacting binaries in the age of the Universe. In our SDSS DR12 white dwarf catalog (Kepler et al. 2016), we found a few thousand stars in the effective temperature and surface gravity ranges attributed to ELMs. We have called these objects sdAs, alluding to their narrow hydrogen line spectra showing sub-main sequence log g. One possible explanation for the sdAs is that they are ELMs. Increasing the ELMs sample would help constrain the number of close binaries in the Galaxy. Interestingly, if they turn out to be A stars with an overestimated log g, the distance modulus would put these young stars in the Galaxy's halo.