DISCOVERING A VARIABLE STAR
During the test phases of the Survey mode of the Pisco software, a new variable star was found near galaxy NGC677.
Top image, a field containing galaxy NGC677 (190 mm telescope - Audine camera in binning 1x1 mode). Composite of 7 single 120-second exposures. Bottom image, the result of subtracting two images made on 29/08/1998 at 0h05m and 2h36m UT. Normally after subtraction stars and galaxies disappear. This is true for all objects except a saturated star (centre) and a variable star (right of centre). Between the two exposures the brightness of the star in question has changed by about 0.5 magnitudes.