2010CBET.2347....2H

Kamil Hornoch, Ondrejov Observatory, reports the independent discovery of M31N 2010-06d by Marek Wolf and himself on co-added 1620-s and co-added 1350-s R-band CCD frames taken by Hornoch on June 30.003 UT and by Wolf on July 1.022, respectively, with the 0.65-m telescope at Ondrejov. M31N 2010-06d is marginally visible on single images used for the co-added frames. Also, the new object is visible on pre-discovery co-added R-band frames taken with the same instrumentation during three previous nights, but is not present on numerous archive images taken at Ondrejov. M31N 2010-06d is located at R.A. = 0:42:55.53, Decl. = +41:19:25.0 (equinox 2000.0), which is 126" east and 196" north of the center of M31. Available R-band magnitudes for M31N 2010-06d, measured by Hornoch: June 9.459 UT, [21.7 (P. Garnavich, C. Littlefield, N. Paul, and S. Bouzid, 1.83-m Vatican Advanced Technology Telescope); 18.152, [21.1 (P. Kubanek, J. Gorosabel, O. L. Gil, and M. Jelinek, 1.23-m telescope at Calar Alto); 27.034, 20.1 ± 0.3 (K. Hornoch, 0.65-m telescope at Ondrejov); 28.014, 19.7 ± 0.2 (Hornoch and P. Hornochova, 0.65-m telescope at Ondrejov); 28.040, 19.7 ± 0.2 (Hornoch and Hornochova); 29.022, 19.2 ± 0.2 (P. Zasche, 0.65-m telescope at Ondrejov); 29.034, 19.0 ± 0.2 (Zasche); 30.003, 18.6 ± 0.15 (Hornoch); 30.022, 18.65 ± 0.1 (Hornoch); July 1.022, 18.3 ± 0.1 (M. Wolf, 0.65-m telescope at Ondrejov).