* Astronomy

Title: New brown dwarf candidates in the Pleiades
Authors: T. Eisenbeiss, M. Moualla, M. Mugrauer, S. Raetz, R. Neuhäuser, T. O. B. Schmidt, Ch. Ginski, M. M. Hohle, A. Koeltzsch, C. Marka, W. Rammo, A. Reithe, T. Roell, M. Vanko
(Version v2)

We have performed deep, wide-field imaging on a ~0.4 deg^2 field in the Pleiades (Melotte 22). The selected field was not yet target of a deep search for low mass stars and brown dwarfs. Our limiting magnitudes are R ~ 22mag and I ~ 20mag, sufficient to detect brown dwarf candidates down to 40MJ. We found 197 objects, whose location in the (I, R - I) colour magnitude diagram is consistent with the age and the distance of the Pleiades. Using CTK R and I as well as JHK photometry from our data and the 2MASS survey we were able to identify 7 new brown dwarf candidates. We present our data reduction technique, which enables us to resample, calibrate, and co-add many images by just two steps. We estimate the interstellar extinction and the spectral type from our optical and the NIR data using a two-dimensional chi^22 fitting.

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