New Red Jewels in Coma Berenices


We have used Sloan Digital Sky Survey-III (SDSS-III) Apache Point Observatory Galactic Evolution Experiment (APOGEE) radial velocity observations in the near-infrared H-band to explore the membership of the nearby (86.7 ± 0.9 pc) open cluster Coma Berenices (Melotte 111), concentrating on the poorly populated low-mass end of the main sequence. Using SDSS-III APOGEE radial velocity measurements, we confirm the membership of eight K/M dwarf members, providing the first confirmed low-mass members of the Coma Berenices cluster. Using R similar to 2000 spectra from IRTF-SpeX, we confirm the independently luminosity classes of these targets, and find their metallicities to be consistent with the known solar mean metallicity of Coma Berenices and of M dwarfs in the solar neighborhood. In addition, the APOGEE spectra have enabled measurement of v sin i for each target and detection for the first time of the low-mass secondary components of the known binary systems Melotte 111 102 and Melotte 111 120, as well as identification of the previously unknown binary system 2MASS J12214070+2707510. Finally, we use Kilodegree Extremely Little Telescope photometry to measure photometric variability and rotation periods for a subset of the Coma Berenices members.



Coma Berenices (Callimachus), Apache Point Observatory Galactic Evolution Experiment (APOGEE), Stars--Clusters, Double stars, Sloan Digital Sky Survey-III (SDSS-III)

US National Science Foundation (AST 1006676, AST 1126413, and AST 1310885)


©2014 The American Astronomical Society