2008CBET.1562....1Y

H. Yamaoka, Kyushu University, reports the discovery by K. Itagaki (Yamagata, Japan) of a variable star on a survey CCD image taken with a 0.21-m f/3 reflector around Nov. 6.456 UT. Confirmation CCD images taken on Nov. 6.460 UT with a 0.60-m f/5.7 reflector show the variable's magnitude to be about 13.0 and its position to be R.A. = 21h37m01.84s, Decl. = +7d14'46".2 (equinox 2000.0). The star was fainter than mag 17.0 on his survey image taken on 2007 Nov. 4.485, and fainter than mag 14.5 on 2008 Oct. 13.587. In the USNO-B1.0 star catalogue, according to Yamaoka, there is a star with position end figures 01s.82, 46".1 and magnitudes B1 = 18.0, R1 = 16.4, B2 = 19.4, R2 = 16.8, I = 17.9; A. Henden, AAVSO notes that the B1 and R1 magnitudes are from Palomar Sky Survey plates taken in 1953, though the USNO-A-catalogue reductions for these same plates yield mags 17.4 and 17.9, suggesting that all the USNO magnitudes for this star are suspect. In the GSC-2.3 catalogue, Yamaoka reports that the variable has magnitudes 18.6-19.6 in the different passbands (which can represent plates taken years apart); Henden notes that the GSC-2.2 catalogue and the USNO-B catalogue give red mag 17.9 and 16.8, respectively, for the variable on apparently the same Palomar Sky Survey plate. In the 2MASS catalogue, the variable has magnitudes J = 16.5, H = 15.8, K = 15.3 (all measured nearly simultaneously). Yamaoka and Henden both suggest that the current outburst amplitude of about 5 mag or so suggests that this could be a dwarf nova. Responding a request by Yamaoka, A. Miyashita (Seikei High School, Japan) confirmed the variable on CCD images taken around Nov. 7.37 with a 0.15-m telescope, reporting the following magnitudes: Nov. 7.369, I_c = 13.29; 7.371, R_c = 14.03; 7.373, V = 13.55, 7.375, B = 13.67.