Open cluster characterization via cross-correlation with a spectral library†

We present a characterization method based on spectral cross-correlation to obtain the physical parameters of the controversial stellar aggregate ESO442-SC04. The data used was obtained with GMOS at the Gemini South telescope, and includes spectra of 17 stars in the central region of the object and 6 standard stars. fxcor was used iteratively to obtain self-consistent radial velocities for the standard stars and average radial velocities for the science spectra. Spectral types, effective temperatures, surface gravities and metallicities were determined using fxcor to correlate cluster spectra with the ELODIE spectral library and select the best correlation matches using the Tonry & Davis ratio. Analysis of the results suggests that the stars in ESO442-SC04 are not bound and, therefore, they do not constitute a physical system.