New Photometry and Spectra of AB Doradus C: An Accurate Mass Determination of a Young Low-Mass Object with Theoretical Evolutionary TracksBased on observations made with ESO telescopes at the Paranal Observatories under program 276. C-5013.

We present new photometric and spectroscopic measurements for the unique, young, low-mass evolutionary track calibrator AB Dor C. While the new K s photometry is similar to that we have previously published, the spectral type is found to be much earlier. Based on new H and K IFS spectra of AB Dor C from Thatte et al.(Paper I), we adopt a spectral type of M5. 5±1.0 for AB Dor C. This is considerably earlier than the M8±1 previously estimated by Close et al. and Nielsen et al. yet is consistent with the M6±1 ...