Small Drift Scan Survey Galaxies Northern Sky

Moreover sensitivity and vignetting variations across the plate, need to be removed. The drift-scan technique is a viable alternative: in this observing mode the telescope tracking is stopped and the CCD is clocked at the sidereal rate. CCD columns are aligned in the east-west direction.

The CCD is read continuously, building up an image of a strip of the sky. Data were reduced in the standard manner, but replacing bias with drift dark (CCD is operating in drift scan mode with the shutter closed). Flatfields were obtained from median averaging sets of data frames.

Astrometry was done using stars whose position was known from the Guide Star Catalog. The galaxy-star classification was done using the east-west FWHM. Then every candidate galaxy was visually inspected.

Important Notice: The published coordinates have errors (up to 6" in the worst case): this is due to a charge smearing problem, which correlates with magnitude. The coordinates in this version are the corrected ones.