L Dwarfs Found in Sloan Digital Sky Survey Commissioning Data. II. Hobby-Eberly Telescope Observations

Low dispersion optical spectra have been obtained with the Hobby-EberlyTelescope of 22 very red objects found in early imaging data from the SloanDigital Sky Survey. The objects are assigned spectral types on the 2MASS system(Kirkpatrick et al. 1999) and are found to range from late M to late L. Thered- and near-infrared colors from SDSS and 2MASS correlate closely with eachother, and most of the colors are closely related to spectral type in thisrange; the exception is the (i^* - z^*) color, which appears to be independentof spectral type between about M7 and L4. The spectra suggest that thisindependence is due to the disappearance of the TiO and VO absorption in thei-band for later spectral types; to the presence of strong Na I and K Iabsorption in the i-band; and to the gradual disappearance of the 8400 Angstromabsorption of TiO and FeH in the z-band.Comment: 20 pages, 7 figures, accepted by AJ, a version with higher resolution figures can be found at ftp://ftp.astro.psu.edu/pub/dps/hetld.p