2003/05/31 by Sebastien Lepine, Sbastien Lpine, R. Michael Rich +1 · 64 citations
Engineering · Physics and Astronomy · #Astronomical Observations and Instrumentation #Astrophysics #Astrophysics and Star Formation Studies #Geology #Paleontology #Physics #Proper motion #Stars #Stellar classification #Stellar, planetary, and galactic studies #Subdwarf #Type (biology) #White dwarf #astro-ph
paper · pdf · doi:10.1086/377069
published in The Astrophysical Journal 591(1), L49-L52 (IOP Publishing) · To appear in The Astrophysical Journal Letters
openalex publication_date 2003/06/09 · arxiv created 2003/06/11 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We report the discovery of LSR 1610-0040, a previously unreported r = 17.5 star with a very high proper motion, μ = 1 46 yr -1 . This very cool star ( b - i = 6.3) is found to have a peculiar spectrum that does not fit into the standard sequence of late-M dwarfs and L dwarfs. Rather, the spectrum is more typical of an ultracool subdwarf, with weak bands of TiO and no detectable VO. But because LSR 1610-0040 is so much redder than any other sdM known, and because it does not appear to fit well into the sdM sequence, we propose that LSR 1610-0040 be assigned a spectral type sdL, making it the first early-type L subdwarf known. Evidence suggests that LSR 1610-0040 is an old, metal-poor star whose mass is just above the limit of hydrogen burning ( M ≈ 0.08 M ☉ ).