A Bright Short Period M-M Eclipsing Binary from the KELT Survey: Magnetic Activity and the Mass-Radius Relationship for M Dwarfs

作者：Lubin Jack B; Rodriguez Joseph E^*; Zhou George; Conroy Kyle E; Stassun Keivan G; Collins Karen; Stevens Daniel J; Labadie Bartz Jonathan; Stockdale Christopher; Myers Gordon; Colon Knicole D; Bento Joao; Kehusmaa Petri; Petrucci Romina; Jofre Emiliano; Quinn Samuel N; Lund Michael B; Kuhn Rudolf B; Siverd Robert J; Beatty Thomas G; Harlingten Caisey; Pepper Joshua; Gaudi B Scott; James David; Jensen Eric L N; Reichart Daniel; Kedziora Chudczer Lucyna

来源：Astrophysical Journal, 2017, 844(2): 134.

DOI：10.3847/1538-4357/aa7947

• binaries: eclipsing
• binaries: general
• stars: low-mass

We report the discovery of KELT J041621-620046, a moderately bright (J similar to 10.2) M-dwarf eclipsing binary system at a distance of 39 +/- 3 pc. KELT J041621-620046 was first identified as an eclipsing binary using observations from the Kilodegree Extremely Little Telescope (KELT) survey. The system has a short orbital period of similar to 1.11 days and consists of components with M-1 = 0.447(+0.052)(-0.0047) M circle dot and M-2 = 0.399(+0.046)(-0.042) M circle dot in nearly circular orbits. The radii of the two stars are R-1 = 0.540(+0.034)(-0.032) R circle dot and R-2= 0.453 +/- 0.017 R circle dot. Full system and orbital properties were determined (to similar to 10% error) by conducting an EBOP (Eclipsing Binary Orbit Program). global modeling of the high precision photometric and spectroscopic observations obtained by the KELT Follow-up Network. Each star is larger by 17%-28% and cooler by 4%-10% than predicted by standard (non-magnetic) stellar models. Strong Ha emission indicates chromospheric activity in both stars. The observed radii and temperature discrepancies for both components are more consistent with those predicted by empirical relations that account for convective suppression due to magnetic activity.

• 出版日期2017-8-1