2009CBET.1896....1S

N. Samus, Institute of Astronomy, Moscow, communicates the discovery of a very probable FU Ori variable star by Anton Khruslov (Tula, Russia). The variable is catalogued as USNO-A2.0 1200-03303169 (R.A. = 5:25:52.00, Decl. = +34:52:30.5 (equinox 2000.0), with blue mag 19.1 and red mag 17.4 from a Palomar Sky Survey (POSS) plate taken in late Dec. 1954). Forty-seven photographic plates in the Moscow collection taken during 1965-1992 and three blue images from the Digitized Sky Survey (1954-1993) show that the variable was always fainter than mag 16 with no other positive detections until 1980. Beginning in 1986, the star is always detected and much brighter: blue mag 14.5 at the end of 1986 (POSS); blue mag 15.2-15.6 during 1987.808-1992.921 (Moscow plates), and blue mag 14.8 at 1993.811 (POSS). The POSS Quick-V survey (1982.805) shows the star still faint, at mag about 19-20. Obviously, the brightening happened at some time between 1982 and 1986. Digitized Sky Survey images after 1986 clearly show a nebula associated with the star, invisible earlier. The star's 2MASS magnitudes (J = 9.62, H = 8.50, K_s = 7.74) indicate the presence of an infrared excess. The star was detected in the ROTSE-I/NSVS survey, where it shows variations between red mag 12.7 and approximately 13.5; two waves of duration 50 to 70 days can be suspected, though the variations are not quite regular. Samus and Elena Kazarovets (Institute of Astronomy, Moscow) add that the GCVS team has assigned this variable the designation V582 Aur.