Electronic Telegram No. 3156 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION CBAT Director: Daniel W. E. Green; Hoffman Lab 209; Harvard University; 20 Oxford St.; Cambridge, MA 02138; U.S.A. e-mail: cbatiau@eps.harvard.edu (alternate cbat@iau.org) URL http://www.cbat.eps.harvard.edu/index.html Prepared using the Tamkin Foundation Computer Network NOVA SAGITTARII 2012 No. 3 = PNV J17522579-2126215 Hitoshi Yamaoka, Kyushu University, reports the discovery by K. Itagaki (Yamagata, Japan) of a possible nova (mag 10.3) on an unfiltered CCD image taken on June 26.5494 UT with a 0.21-m reflector, the position given as R.A. = 17h52m25s.79, Decl. = -21d26'21".5 (equinox 2000.0); Itagaki confirmed the new variable at mag about 10.2 on an unfiltered image taken on June 26.565 with a 0.60-m reflector. Itagaki has posted an image of the variable at the following website URL: http://www.k-itagaki.jp/images/pnv.jpg. The variable was designated PSN J17522579-2126215 when it was posted at the Central Bureau's TOCP webpage. Additional CCD magnitudes for PSN J17522579-2126215: June 21.985, [12.0 (Herman Mikuz, Crni Vrh Observatory; 120-mm f/4 camera lens + CCD; object position close to edge of field); June 22.988, [12.0 (Mikuz); June 24.050, [12.0 (Mikuz); June 25.666, [16.0 (Itagaki); June 26.540, 9.9 (Yukio Sakurai, Mito, Ibaraki-ken, Japan; independent discovery on four 20-s frames taken with a Fuji FinePix S2 Digital Camera + Nikon 180-mm f/2.8 lens; position end figures 25s.59, 22".9, measured by S. Nakano, Sumoto, Japan, who noted a probable error of +/- 5" and limiting magnitude about 11.5); June 26.640, 10.0 (Itagaki); June 27.192, 9.0 (C. Jacques and E. Pimentel; using a 0.25-m f/3.4 astrograph + clear filter at the RAS Observatory near Mayhill, NM, U.S.A.; position end figures 25s.79, 21".9; limiting mag 15.8; image posted at URL http://ceamig-rea.net/tocp/PNV_J17522579-2126215.jpg); June 26.919, R = 9.7 (Mikuz); June 27.193, 9.9 (Jacques and Pimentel; red filter); June 27.194, 10.1 (Jacques and Pimentel; visual filter); June 27.195, 10.5 (Jacques and Pimentel; blue filter); June 27.253, B = 11.2, V = 9.7, R_c = 8.7, I_c = 7.7 (T. Yusa, Osaki, Japan; position end figures 25s.77, 21".5, USNO-B1.0 reference stars; remotely using a 0.25-m f/3.4 hyperbolic astrograph + SBIG ST-10XME camera at the RAS Observatory, iTelescope network, near Mayhill; position and magnitude measured from a three co-added 30-s images, limiting magnitude 15.7); June 27.3, R = 8.9 (Ernesto Guido, Giovanni Sostero, and Nick Howes; remotely with a 0.10-m f/5 reflector of the ITelescope network of the RAS Observatory near Mayhill; position end figures 25s.79, 21".6; reference stars from CMC-14 catalogue; an animation showing a comparison between their image and a red Digitized Sky Survey plate from 1996 is posted at URL http://bit.ly/M3mhZn; their annotated confirmation image is posted at URL http://bit.ly/OrjMA9); June 27.3101, V = 9.804 +/- 0.032 (Carl Hergenrother, Lunar and Planetary Laboratory, University of Arizona; obtained remotely with the Sierra Stars 0.61-m telescope; V and B magnitudes derived from the AAVSO VPHOT program, while the R-band magnitudes were measured using stars from the CMC-14 catalogue; position end figures 25s.79, 21".7, relative to the CMC-14 astrometric catalogue); June 27.3129, B = 11.311 +/- 0.009 (Hergenrother); June 27.355, B = 11.36, V = 9.80, R_c = 8.82, I_c = 7.65 (Seiichiro Kiyota, Tsukuba, Japan; 25-cm reflector + SBIG ST-10XME CCD camera located near Mayhill -- T4, iTelescope.net -- used for photometry; position end figures 25s.69, 21".8; 43-cm reflector + FLI-PL6303E CCD camera -- T21 -- used for astrometry); June 28.3075, V = 11.019 +/- 0.046 (Hergenrother); June 28.3083, B = 12.282 +/- 0.024 (Hergenrother); June 28.3107, R = 9.62 +/- 0.06 (Hergenrother); June 28.612, I_c = 8.56 (Hiroyuki Maehara, Kwasan Observatory, Kyoto University; 0.25-m telescope); June 28.613, R_c = 9.24 (Maehara); June 28.614, V = 11.24 (Maehara); June 28.616, B = 12.49 (Maehara). Jacques and Pimentel note that no progenitor star could be identified on a Palomar Sky Survey plate from Sept. 1950. Mikuz's June 26 image is posted at website URL http://www.observatorij.org/vstars/PNVJ17522579-2126215.jpg; Yusa's image is posted at http://space.geocities.jp/yusastar77/supernova/PSNinSgr_120627.htm. L. Kiss and K. Sarneczky, Konkoly Observatory, Hungary; and J. Kovacs and T. Borkovits, ELTE Gothard Observatory, Hungary, report on a medium-resolution optical spectrogram of PNV J17522579-2126215 obtained with the 0.5-m reflector of the Gothard Observatory on June 26.95 UT. The spectrum does not contain any strong emission lines, with a clearly identifiable H-beta line in absorption and a strong interstellar absorption of the sodium D doublet. The H-alpha line is possibly seen in absorption. Two narrow emission lines are also visible around 575.0 nm, each with FWZI about 60 km/s. The spectrum safely excludes the nova nature of the object, which is presumably a dwarf nova in outburst phase. The estimated visual brightness of the target was about mag 9.5, based on the guider image. Kazuyoshi Imamura, Okayama University of Science (OUS), reports on obtaining a low-resolution spectrum (R about 400) of PNV J17522579-2126215 on June 28.593 UT, using the DSS-7 spectrometer attached to the 0.28-m Schmidt-Cassegrain telescope at the OUS observatory. Broad and prominent emission lines of the Balmer series, He I (706.5-nm), O I (777.3-nm), and Mg II (788.0-nm) can be seen in the spectrum. The Balmer lines show asymmetrical profiles; the FWHM of H-alpha is approximately 4100 km/s. From this result, the variable is thought to be a classical nova with a large expansion velocity. The spectrum has been posted at the following website URL: http://blog-imgs-44.fc2.com/t/n/b/tnblab/pnSGR_20120628.png. Hiroyuki Maehara, Kwasan Observatory, Kyoto University, obtained a low-resolution spectrum (R about 300) of PNV J17522579-2126215 on June 28.647 with a 25-cm telescope at Kwasan Observatory. The spectrum shows broad H-alpha emission line (FWHM about 4000 km/s), which suggests that the object is a classical nova. The spectrogram has been posted at the following website URL: http://www.kwasan.kyoto-u.ac.jp/~maehara/novae/pnv1752.png. Christian Buil writes that a spectrogram taken on June 28.864 UT with a 0.28-m telescope (+ LISA spectrograph) at the Castanet Observatory in France reveals that the nova-like nature of PNV J17522579-2126215 is confirmed; the spectrum is dominated by intense hydrogen emission. The H_alpha line shows a FWHM of 4500 km/s. Ulisse Munari, Istituto Nazionale di Astrofisica, Padova Astronomical Observatory, observed PNV J17522579-2126215 with the 1.22-m Asiago telescope (operated by the Department of Physics and Astronomy of the University of Padova) on June 28.95 UT (presumed), at a dispersion on 0.231 micron/pixel over the wavelength range 330-770 nm. The spectrum is that of a nova of the He/N type, with hydrogen Balmer and He I in strong emission. The FWHM of the emission lines is 4500 km/s. The object appears to be heavily reddened, with strong interstellar Na I lines visible in absorption. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2012 CBAT 2012 June 29 (CBET 3156) Daniel W. E. Green