Details

Autor(en) / Beteiligte

• Benedict, G F
• Henry, T J
• Franz, O G
• McArthur, B E
• Wasserman, L H
• Jao, Wei-Chun
• Cargile, P A
• Dieterich, S B
• Bradley, A J
• Nelan, E P
• Whipple, A L

Titel

THE SOLAR NEIGHBORHOOD. XXXVII. THE MASS–LUMINOSITY RELATION FOR MAIN-SEQUENCE M DWARFS

Ist Teil von

• The Astronomical journal, 2016-11, Vol.152 (5), p.141-141

Ort / Verlag

United States

Erscheinungsjahr

2016

Quelle

Elektronische Zeitschriftenbibliothek - Frei zugängliche E-Journals

Beschreibungen/Notizen

• We present a mass-luminosity relation (MLR) for red dwarfs spanning a range of masses from 0.62 M[middot in circle] to the end of the stellar main sequence at 0.08 M[middot in circle]. The relation is based on 47 stars for which dynamical masses have been determined, primarily using astrometric data from Fine Guidance Sensors (FGS) 3 and 1r, white-light interferometers on the Hubble Space Telescope (HST), and radial velocity data from McDonald Observatory. For our HST/FGS sample of 15 binaries, component mass errors range from 0.4% to 4.0% with a median error of 1.8%. With these and masses from other sources, we construct a V-band MLR for the lower main sequence with 47 stars and a K-band MLR with 45 stars with fit residuals half of those of the V band. We use GJ 831 AB as an example, obtaining an absolute trigonometric parallax, [pi] sub(abs)= 125.3 + or - 0.3 mas, with orbital elements yielding M sub(A)= 0.270 + or - 0.004 M[middot in circle] and M sub(B)= 0.145 + or - 0.002 M[middot in circle]. The mass precision rivals that derived for eclipsing binaries. A remaining major task is the interpretation of the intrinsic cosmic scatter in the observed MLR for low-mass stars in terms of physical effects. In the meantime, useful mass values can be estimated from the MLR for the ubiquitous red dwarfs that account for 75% of all stars, with applications ranging from the characterization of exoplanet host stars to the contribution of red dwarfs to the mass of the universe.