Electronic Telegram No. 3571 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 SUPERNOVA 2013do IN UGC 12137 = PSN J22395067+3812443 Bin Wang, Shaoxing, Zhejiang, China; and Xing Gao, Urumqi, Xinjiang, China, report the discovery of a possible supernova (mag approximately 17.0) on an unfiltered 40-s CCD survey image (limiting mag about 19.5) taken by Xing Gao in the course of the Xingming Sky Survey around June 16.824 UT using a 36-cm Celestron C14 Schmidt-Cassegrain telescope at Mt. Nanshan. The new object is approximately located at R.A. = 22h39m50s.67, Decl. = +38d12'44".3 (equinox 2000.0), which is about 14".0 east and 11".2 south of the center of UGC 12137 = PGC 69439. Nothing is visible at this position on a Digitized Sky Survey image from 1989 Sept. 3 (limiting mag about 19.8). The Xingming images are posted at website URL http://www.xjltp.com/XOSS/XM06BW/XM06BW.htm. The variable was designated PSN J22395067+3812443 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2013do based on the spectroscopic confirmation reported below. Additional CCD magnitudes for 2013do: 2013 June 1, [19.0 (Wang and Gao); 17.763, 17.0 (Joseph Brimacombe, Cairns, Australia; 41-cm telescope + infrared filter; bandpass > 700 nm; position end figures 50s.65, 43".5; image posted at URL http://www.flickr.com/photos/43846774@N02/9074451038/); 18.253, 18.1 (L. Elenin, Lyubertsy, Russia, and I. Molotov, Moscow; three 150-s images taken remotely with a 0.45-m f/2.8 telescope at the ISON-NM Observatory near Mayhill, NM, USA; position end figures 50s.54 +/- 0".18, 44".8 +/- 0".19; UCAC-4 reference stars; limiting mag about 18.8; image posted at website URL http://spaceobs.org/images/TOCP/PSNJ22395067+3812443-20130618.png); 21.832, 17.2 (Wang and Gao; position end figures 50s.69, 44".3); 22.819, 17.1 (Wang and Gao; position end figures 50s.70, 43".3). A. A. Rachubo and D. C. Leonard, San Diego State University; K. Follette, P. Sheehan, and D. McCarthy, University of Arizona; J. Moustakas, Siena College; V. Bailey, J. Barrows, E. Bosset, E. Buckley, D. Burd, J. Calahan, I. Ceesay, E. Douglas, C. Feeney, T. Fornari, A. Fox, H. Fishwick, H. Gano, C. Green, J. Griggs, K. Hart, S. Hart, K. Hartman, A. Holt, E. Hooper, S. Hume, S. Jaeggli, D. Lesser, M. Kerr, C. Kopans-Johnson, K. Kumar, A. Lackey, S. Laube, E. Marshall, M. Martinez, G. Mehta, K. Melbourne, M. Meshel, C. Myers, E. Puranen, A. Schlingman, W. Schlingman, W. M. Schlingman, K. Shen, N. Stock, C. Stillman, J. Tinker, and B. Whitesell, 2013 Advanced Teen Astronomy Camp, report that inspection of a low-dispersion optical spectrum (range 350-660 nm) of PSN J22395067+3812443 = SN 2013do, obtained with the 2.3-m Bok telescope (+ Boller & Chivens spectrograph) at Steward Observatory on June 26 UT, shows it to be a type-II supernova. Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) finds best matches with a number of normal type-IIP supernovae ranging in age from about one to two weeks after maximum light. Adopting the recession velocity for UGC 12137 of 4685 km/s (Wegner et al. 1993, A.J. 105, 1251; via the NASA/IPAC Extragalactic Database), an expansion velocity of 8900 km/s is derived from the position of the H_beta (rest wavelength 486.1 nm) minimum. S. Tinyanont, Harvey Mudd College; Y. Cao, California Institute of Technology; and M. M. Kasliwal, Observatories of the Carnegie Institution and Princeton University, report that spectroscopic observations (range 330-1000 nm) of PSN J22395067+3812443 = SN 2013do were obtained on June 27.27 UT with the Dual Imaging Spectrograph on the 3.5-m ARC telescope at Apache Point Observatory. The spectrum shows prominent H-alpha emission with a P-Cyg profile. The minimum of the H-alpha absorption is at 642.5 nm. Using the redshift z = 0.015627 for UGC 12137 (from Wegner et al. 1993, A.J. 105, 1251; via NED), this corresponds to a velocity of 11000 km/s. Running the SNID software, the spectrum resembles SN 2004et at fifteen days after maximum, indicating that 2013do is a type-II-P supernova. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2013 CBAT 2013 July 1 (CBET 3571) Daniel W. E. Green