Astron. Astrophys. 325, 559-562 (1997)

2. Observations and data reduction

On February 14th - 18th 1994 704 CCD observations in B of BT Cnc were obtained as specified in Table 1. The 0.77 m (0.45 m effective aperture) Brorfelde Schmidt telescope was used for the observations with a 1024 1024 pixel peltier-cooled CCD. The 28 28 arcminutes field was centered on 08:39:40, +19:45:00 in Praesepe. In order to observe as many stars as possible in the open cluster, the telescope was slightly defocused in order to prevent saturated pixels from the brightest (about 6th magnitude) stars.

Table 1. Observations of BT Cnc on three nights of February 1994. Beginning and end of each observation night are given by HJD of the first and last observation

The photometric reductions were performed using MOMF, Version 2.1 (Multi Object Multi Frame photometric package, see Kjeldsen & Frandsen 1992).

© European Southern Observatory (ESO) 1997

Online publication: April 28, 1998

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