Electronic Telegram No. 2813 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 SCORPII 2011 No. 2 = PNV J16364440-4132340 = PNV J16364300-4132460 Two independent discoveries of an apparent nova in Scorpius have been received by the Central Bureau. John Seach (Chatsworth Island, NSW, Australia) reported finding a star of mag 9.8 on four CCD images taken on Sept. 6.37 UT with a digital single-lens-reflex camera (+ 50-mm f/1.2 lens; limiting mag 10.5), with the position given as R.A. = 16h36m43s, Decl. = -41d32'46" (equinox 2000.0), adding that nothing was visible at this position on his image taken on Sept. 5.36 (limiting mag 10.5). H. Yamaoka, Kyushu University, forwards a report that Yuji Nakamura (Kameyama, Mie, Japan) discovered this possible nova at mag about 9.7 on five unfiltered CCD images taken with a 150-mm-focal-length telephoto lens on Sept. 6.431; Nakamura measured the position of the new object as R.A. = 16h36m44s.4, Decl. = -41d32'34" (uncertainty about 30"), adding that nothing is visible at this position on his image taken on Aug. 29.451 (limiting mag about 12.0). When Yamaoka posted Nakamura's discovery observation on the Central Bureau's Transient Object Confirmation Page, it was assigned the designation PNV J16364440-4132340 was assigned; the posting of Seach's discovery observation yielded a second designation, PNV J16364300-4132460. Additional magnitudes for PNV J16364440-4132340 = PNV J16364300-4132460, visual unless noted otherwise (some reported via E. Waagen, AAVSO): Sept. 7.46 UT, I_c = 8.62, R_c = 9.48, V = 10.51 (Hiroyuki Maehara, Kwasan Observatory, Kyoto University; 0.25-m telescope); 7.48, V = 10.52 (Steve James, Queanbeyan, NSW, Australia); 7.50, 9.1 (Ernesto Guido, Nick Howes, and Giovanni Sostero; remotely through the 2.0-m f/10 Ritchey-Chretien "Faulkes Telescope South" + Bessel R filter; position end figures 44s.29, 37".7; USNO-B1.0-catalogue reference stars); 7.507, V = 10.44 (Peter Lake, Wonga Park, Victoria, Australia); 7.509, V = 10.40 (Lake); 7.512, V = 10.41 (Lake); 7.514, V = 10.42 (Lake); 7.516, V = 10.38 (Lake); 7.53, B = 11.88, V = 10.73, R_c = 9.75, I_c = 8.77 (Seiichiro Kiyota, Tsukuba, Japan, remotely using a 31.7-cm Global-rent-a-scope + SBIG ST-10 camera at Officer, Australia; position end figures 44s.28, 37".6); 7.545, 10.6 (Rod Stubbings, Tetoora Park, Victoria, Australia); 7.545, 10.6 (Stubbings); 8.392, 11.0 (Stubbings); 9.406, 10.3 (T. Noguchi, Chiba-ken, Japan, 0.23-m Schmidt-Cassegrain reflector + unfiltered BITRAN BT-11E CCD camera; limiting magnitude 16.5; position end figures 44s.26, 37".4; UCAC3 reference stars; communicated by Syuichi Nakano, Sumoto, Japan). Kiyota's images is posted at website URL http://meineko.sakura.ne.jp/ccd/PNV_J16364440-4132340-110907.jpg. Guido et al. add that a USNO-B1.0-catalogue star with red mag 15.08 appears very close to the position (within 0".06) of the variable, and they have posted a comparison animation with a 1997 red Digitized Sky Survey (DSS) plate at website URL http://bit.ly/ojz76D. Paul Camilleri (New Castle, NSW, Australia) and Steven Williams (Sydney, NSW) write that they obtained images with red, blue, and green filters remotely using a 0.35m f/6 reflector (+ ST8 camera) at Grove Creek/Skylive Observatory, Trunkey Creek, NSW, yielding position end figures 44s.28, 37".7 and red mag 9.7 for the variable (no date given); they add that a star of mag 14-15 is visible on 1.2-m U.K. Schmidt Telescope plates, providing position end figures 44s.29, 37".6 from DSS images (mag 14.3 measured from an infrared plate taken on 1980 May 5.63; mag 15.2 measured from a red IIIa-F plate + OG590 filter on 1997 Apr. 30.64). A. Arai, T. Kajikawa, C. Naka, Kyoto Sangyo University, write that they performed low-resolution optical spectroscopic observations (R about 580) of PNV J16364440-4132340 on Sept. 7.42 UT using the Araki telescope at Koyama Astronomical Observatory. The spectrum exhibits broad Balmer emissions and Fe II multiplet emissions on a highly reddened continuum light. The H-alpha emission line shows an asymmetric profile with FWZI about 6000 km/s. Other significant features are invisible in the spectrum (posted at website URL http://www.cc.kyoto-su.ac.jp/~kao/blog/index.php/view/127). These features suggest that the object is an "Fe II"-type classical nova, highly reddened by the interstellar medium. F. Walter, Stony Brook University; and J. Seron, Cerro Tololo Interamerican Observatory (CTIO), confirm that PNV J16364300-4132460 is a galactic nova. A spectrum obtained on Sept. 8.091 UT with the SMARTS/CTIO 1.5-m reflector (+ RC spectrograph; range 565-695 nm; resolution 0.31 nm) shows broad H-alpha emission with a triple-peaked spectrum reminiscent of early recurrent-novae spectra; the FWHM of the line is about 3000 km/s, and the equivalent width is about 19.0 nm. The nova is young; the continuum shows a number of broad absorption lines, as well as narrow interstellar Na D absorption (EW about 0.36 nm). No emission is evident aside from H-alpha. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2011 CBAT 2011 September 10 (CBET 2813) Daniel W. E. Green