Electronic Telegram No. 2731 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 DWARF NOVA IN PEGASUS (PNV J21095047+1348396) H. Yamaoka, Kyushu University, forwards the discovery by K. Itagaki (Yamagata, Japan) of a possible nova on May 24.672 UT during a survey program performed by himself and H. Kaneda (Hokkaido, Japan). The variable, which was designated PNV J21095047+1348396 when posted on the Central Bureau's TOCP webpage, was confirmed at unfiltered CCD mag about 11.5 by Itagaki with a 0.60-m reflector on May 24.699, the position measured to be R.A. = 21h09m50s.47, Decl. = +13d48'39".6 (equinox 2000.0); Itagaki has posted his confirmation image at website URL http://www.k-itagaki.jp/images/pnv.jpg. Additional approximate magnitudes for PNV J21095047+1348396 (unfiltered CCD unless noted otherwise): May 17.71, [14.9 (Itagaki, 0.21-m reflector); May 18.76, [12.3 (Itagaki, 180-mm-f.l. telephoto lens); May 25.3, 11.0 (Ernesto Guido and Giovanni Sostero; remotely with a 0.25-m f/3.4 reflector at the GRAS Observatory near Mayhill, NM, U.S.A.; position end figures 50s.46, 39".6, which they also note to be very close to a star of red mag 18.8 in the USNO- B1.0 catalogue; their image compared to a red Digitized Sky Survey plate from 1991 is posted at website URL http://bit.ly/mycwOt); May 25.676, 11.6 (K. Kadota, Ageo, Japan; 0.25-m f/5 reflector + SBIG ST-9E camera; position end figures 50s.47, 39".7; communicated by S. Nakano, Sumoto, Japan; image posted at URL http://members.jcom.home.ne.jp/kenic-k/image/PNVinPeg-20110525.jpg); May 26.076, 11.5 (P. Schmeer, Bischmisheim, Germany; visual). Itagaki/Yamaoka note also that a faint star (mag about 19) is located within several arcsec of Itagaki's position in the USNO-B1.0 catalogue (position end figures 50s.427, 39".95). Akira Arai, Koyama Astronomical Observatory, Kyoto Sangyo University, writes that optical low-dispersion spectroscopic observations (range 400-750 nm; R about 600 at H-alpha) of PNV J21095047+1348396 were made on May 25.67 UT using the 1.3-m Araki telescope (+ LOSA/F2). The spectrum shows a blue continuum with H_beta and H_gamma absorptions and no significant blue-shifts. No obvious line is visible at H_alpha. These suggest that an emission component of H_alpha could be filling in the absorption line and that the object is a dwarf nova in outburst. Their spectrum has been posted at website URL http://www.cc.kyoto-su.ac.jp/~kao/blog/index.php/view/94. D. D. Balam, Dominion Astrophysical Observatory, National Research Council of Canada (NRCC); M. L. Graham, Las Cumbres Observatory Global Telescope, University of California at Santa Barbara; E. Y. Hsiao, Lawrence Berkeley Laboratory; and D. W. E. Green, Harvard University, report that a spectrogram (range 382-714 nm, resolution 0.3 nm) of PNV J21095047+1348396, obtained on May 29.42 UT with the 1.82-m Plaskett Telescope of the NRCC, shows a steep blue continuum with broad asymmetric Balmer absorption lines. H-alpha exhibits a broad absorption profile with a sharp (1.2-nm FWHM) central emission spike. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2011 CBAT 2011 May 30 (CBET 2731) Daniel W. E. Green