2012CBET.3089....1K

Stanislav Korotkiy, Ka-Dar Observatory; and Kirill Sokolovsky, Astro Space Center, Lebedev Physical Institute, and Sternberg Astronomical Institute, Moscow State University, report the discovery of a possible nova (magnitude 9.6) on three 30-s unfiltered CCD images (limiting magnitude about 14.0) obtained on Apr. 21.011 UT with a wide-field survey camera (+ 135-mm-f.l. f/2 telephoto lens + ST8300M camera) at Ka-Dar Observatory's TAU Station near Nizhny Arkhyz, Russia. The new object is located at R.A. = 17:45:28.03, Decl. = -23:05:22.8 (equinox 2000.0; UCAC2 reference stars; uncertainty 1"), noting that a red USNO-B1.0-catalogued star (magnitudes R1 = 16.21, B2=18.61) lies just 0".6 away from the variable's position. Their discovery images are posted at URL http://www.astroalert.su/files/pnv_j17452791-2305213.jpg. The variable was designated PSN J17452791-2305213 when it was posted at the Central Bureau's TOCP webpage.

Additional magnitudes for PSN J17452791-2305213 (from unfiltered CCD images unless noted otherwise): Apr. 17.99, [14.0 (Korotkiy and Sokolovsky); 19.73, [12.0 (N. J. Brown, Two Rocks, W. Australia; TMax 400 film + 135-mm-f.l. f/2.0 camera lens); 20.84, 10.2 (R. J. Gao, Xingming Observatory, China; V-band suggested; position end figures 28s.02, 23".3; USNO-A2.0 reference stars; no instrumentation details given); 21.654, 8.8 (John Seach, Chatsworth Island, NSW, Australia; digital camera + 50-mm-f.l. f/1.0 lens); 22.353, V = 9.58, B = 10.30, I_c = 7.70 (Seiichiro Kiytota, Tsukuba, Japan; remotely with 25-cm reflector + ST-10XME camera near Mayhill, NM, USA; position end figures 28s.03, 22".9); 22.4, 9.1 (Ernesto Guido, Nick Howes, and Giovanni Sostero; 0.25-m f/3.4 reflector, remotely from Mayhill; position end figures 28s.02, 23".2; reference stars from UCAC-3 catalogue; they also note the USNO-B1.0 star only 0".2 away; they have posted a comparison between their confirmation image and an archival red 1996 plate from the Digitized Sky Survey at website URL http://bit.ly/IIV8oN); 22.415, 9.0 (L. Elenin, Lyubertsy, Russia; and I. Molotov, Moscow, Russia; remotely with a 0.45-m f/2.8 telescope at the ISON-NM Observatory near Mayhill, NM, USA; position end figures 28s.02, 23".1; NOMAD reference stars; limiting mag about 17.8); 22.454, V = 9.06 ± 0.10 (R. A. Koff, Bennett, CO, USA; Meade 0.25-m f/10 reflector + Apogee AP-47p camera; limiting magnitude 15.3; position end figures 28s.02, 22".9; UCAC3 reference stars); 22.462, 9.4 (Markku Nissinen, Varkaus, Finland; remotely with a 15- cm f/7.3 refractor + color CCD camera of "itelescope.net" near Mayhill; position end figures 28s.02, 23".0; corrected GSC 1.1 catalogue stars; limiting magnitude 17.2; nothing brighter than mag 18 on a red Palomar Sky Survey F plate at this position); 22.718, 9.6 (Koichi Nishiyama, Kurume, Japan; and Fujio Kabashima, Miyaki, Japan; limiting magnitude 17.6; Meade 200R 0.40-m f/9.8 reflector + SBIG STL1001E camera; position end figures 28s.05, 23".2); 22.979, 9.7 (Korotkiy and Sokolovsky); 23.217, 10.0 (Hermann Koberger; 0.6-m reflector at Vilaflor, Tenerife; green magnitude from a digital SLR camera; a low-resolution spectrum at 100 lines per mm from Apr. 23.243 showed H_alpha emission for the object; communicated by Wolfgang Vollmann); 23.976, 10.0 (Korotkiy and Sokolovsky); 23.993, 10.0 (Korotkiy and Sokolovsky; 40-cm telescope; position end figures 28s.03, 22".7, uncertainty 0".3; measured by Korotkiy and V. Gerke); Kiytota's image is posted at website URL http://meineko.sakura.ne.jp/ccd/PNV_J17452791-2305213-120422.jpg.