Two New Late–Type Degenerates: Implications for the White Dwarf Luminosity Function

Abstract

Recent preliminary USNO CCD parallax solutions for over 100 fields have yielded relative parallaxes with formal errors less than 0″.0030 for approximately 60 faint (15.9 ≤ V ≤ 20.3) stars. The stars observed include a variety of late-type dwarfs, extreme subdwarfs, and degenerates. Among the latter are the well-known, spectroscopically confirmed degenerates LP543–32/33 (= LHS239/240), LP131–66 (= LHS342), LP754–16 (= LHS483), LP702–7 (= LHS542), LP374–4 (= LHS2364), and LP322–800 (= LHS2673), all of which have Mv ≥ 15.0. In addition, two “new” (in terms of previously lacking both spectroscopic confirmations and absolute luminosity estimates) late-type degenerates were identified — LP53–7 (= LHS1405) and LP550–178 (= LHS2288) — both with proper motions in the range