Observatory in southeastern Arizona. For the first 16 months of observation, the detector was a 2048×4096 SITe ST-002A CCD. Those echelle spectrograms have 21 orders, span the wavelength range 4920–7100Å (Eaton&Williamson 2007), and have a resolution of 0.24 Å. In the summer of 2011 the SITe CCD detector
and Dewar were retired. The new AST detector is a Fairchild 486 CCD, having 4096×4096 15μm pixels, that is housed in a new Dewar. See Fekel et al. (2013) for additional information about the 2 m AST upgrades. The spectrograms that were obtained with this new detector have 48 orders covering the wavelength range 3800–8260 Å. The spectral resolution with the Fairchild CCD is the same, 0.24 Å, as that with the SITe CCD. Depending on weather conditions and the CCD used, we acquired spectra
that have signal-to-noise ratios (S/Ns) ranging from 70 to 140
at 6000 Å.