SDSS DR7 M dwarfs

For each spectrum, we provide measurements of the spectral type, a number of molecular band heads, and the H{alpha}, H{beta}, H{gamma}, H{delta}, and CaII-K emission lines. In addition, we calculate the metallicity-sensitive parameter {zeta} and identify a relationship between {zeta} and the g-r and r-z colors of M dwarfs.

We assess the precision of our spectral types (which were assigned by individual examination), review the bulk attributes of the sample, and examine the magnetic activity properties of M dwarfs, in particular those traced by the higher order Balmer transitions. Our catalog is cross-matched to 2MASS infrared data, and contains photometric distances for each star. Finally, we identify eight new late-type M dwarfs that are possibly within 25 pc of the Sun.