2010CBET.2291....1B

G. Bock, Windaroo, Queensland, Australia, reports the discovery of an apparent supernova (red mag 17.2) by Brendan Downs (Backyard Observatory Supernova Search team, Ipswich, Queensland) on 60-s unfiltered CCD images taken during May 22.612-22.661 UT with a Meade 35-cm f/6.3 reflector (+ ST7 CCD camera). Bock measures the new object's position to be R.A. = 19:27:17.72, Decl. = -59:18:44.9 (equinox 2000.0), which is 27" west and 9" north of the nucleus of IC 4854. Nothing is visible at this position on Digitized Sky Survey red, blue, and infrared images (limiting red mag > 19). A confirming image taken by L. A. G. Monard (Pretoria, S. Africa) on May 24.056 clearly shows 2010dc at red mag 17.3 (measured by Bock). Bock adds that nothing is visible at the position of 2010dc on images taken by Monard on May 6 (limiting mag about 19) and by S. Parker (Oxford, Canterbury, New Zealand) on May 2 (limiting red mag > 17.5).