The Optical Mass‐Luminosity Relation at the End of the Main Sequence (0.08–0.20M_⊙)

Abstract

The empirical mass-luminosity relation at is presented for stars with masses 0.08È0.20 based M V M _ upon new observations made with Fine Guidance Sensor 3 on the Hubble Space T elescope. The targets are nearby, red dwarf multiple systems in which the magnitude di †erences are typically measured tô 0.1 mag or better. The values are generated using the best available parallaxes and are also accu-M V rate to^0.1 mag, because the errors in the magnitude di †erences are the dominant error source. In several cases this is the Ðrst time the observed sub-arcsecond multiples have been resolved at optical wavelengths. The mass-luminosity relation deÐned by these data reaches to and provides a M V \ 18.5 powerful empirical test for discriminating the lowest mass stars from high-mass brown dwarfs at wavelengths shorter than 1 km.

Astrometric Discovery of GJ 164B

“…We use the visible mass-luminosity relation ( MLR; Henry et al 1999) to relate the absolute luminosity of each component to its mass. As the mass and absolute luminosity of the secondary decrease, becomes negligible compared with f in equation (2), and the MLR also becomes inapplicable.…”

“…We estimate that the V magnitude difference between components is at least 2.2. We base this limit on the previous successful analysis of Wolf 1062 (Gl 748), an SB2 with Ám ¼ 1:8 (Benedict et al 2001), and, in an ongoing investigation, on marginal detection of the two components of Wolf 922 (Gl 831; Ám ¼ 2:1; Henry et al 1999), but at periastron (largest ÁV r ). This would restrict the mass of the companion to be less than 0.11 M , confirming the astrometric upper limit ( Table 2).…”

“…As expected, we are detecting the largest mass companions with the largest signals first, and we expect to detect smaller mass companions down to a limit of $M J as the baselines and sensitivities increase. Pravdo & Shaklan (2003) reported the detection of a low-mass companion to GJ 1245A, GJ 1245C ( Harrington & Dahn 1984;McCarthy et al 1988;Harrington 1990), with a mass of $0.07 M (Henry et al 1999). Here we report the discovery of another low-mass companion around a nearby M star, GJ 164.…”

Discovery of a Gas Giant Planet in Microlensing Event Ogle-2014-BLG-1760

“…For each MCMC fit, the source distance is picked randomly from this distribution. From emperical mass-luminosity relations (Henry & McCarthy 1993;Henry et al 1999;Delfosse et al 2000) and massdistance relations, we estimated the lens distance, host-star and planet mass, host-star brightness, and host-star and planet projected separation using a method similar to that used by Batista et al (2015) and Bennett et al (2015). Then, we calculated mean, median, and posterior distributions for each parameter from all of these MCMC fits, as seen in Table 3 , spans the range from the mass of Saturn to that of Jupiter.…”

The very low mass multiple system LHS 1070. A testbed for model atmospheres for the lower end of the main sequence

“…The spectral types for the A, B, and C components were found to be M5.5-M6, M8.5, and M9-M9.5, respectively (Leinert et al 2000). A fourth component was suspected very close to the primary by Henry et al (1999) from Hubble Space Telescope (HST) Fine Guidance observations, but this detection is no longer considered to be real (Henry, priv. comm.).…”