Supernova 2013?? in NGC 2554 = Psn J08175346+2328105
Abstract
Further to CBET 3422, K. Blanchard, W. Zheng, S. B. Cenko, W. Li, and A. V. Filippenko report the LOSS discovery of an apparent supernova in NGC 2554 on unfiltered KAIT images: SN 2013 UT R.A. (2000.0) Decl. Mag. Offset 2013?? Mar. 25.19 8 17 53.46 +23 28 10.5 15.1 0".6 W, 9".1 S A finding chart for the variable was posted at the following website URL: http://astro.berkeley.edu/~zwk/findingchart/PSN_J08175346+2328105.jpg. The variable was designated PSN J08175346+2328105 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2013?? based on the spectroscopic confirmation reported below. Additional magnitudes for 2013??: Mar. 13.19 UT, [18.5 (KAIT); 25.887, V = 15.2 (Johan Warell, Skurup, Sweden; 25-cm reflector + SXV-H9 camera; photometry uncertain due to closeness of variable to the core of NGC 2554; scale 2".23/pixel; position end figures 53s.51, 11".2; USNO-B1 reference stars); 25.895, R = 13.6 (Warell; position end figures 53s.49, 11".7); 26.119, 15.4 (L. Elenin, Lyubertsy, Russia, and I. Molotov, Moscow; remotely taken with a 0.45-m f/2.8 telescope at the ISON-NM Observatory near Mayhill, NM, USA; position end figures 53s.54 +/- 0".08, 11".3 +/- 0".06; UCAC-4 reference stars; limiting mag about 18.8; image posted at http://spaceobs.org/images/TOCP/PSNJ08175346+2328105-20130326.png); 26.32, 15.1 (KAIT; also, R magnitude around 15.0); 27.115, 14.8 (Joseph Brimacombe, Cairns, Australia; remotely using a 51-cm RCOS telescope + STL11K camera at the New Mexico Skies observatory near Mayhill, NM; infrared filter, bandpass > 700 nm; position end figures 53s.53, 10".7; image posted at URL http://www.flickr.com/photos/43846774@N02/8599691309/); 31.857, 14.7 (S. Foglia and G. Galli, Pogliano Milanese, Italy; 0.28-m f/6.8 Schmidt-Cassegrain reflector + ST8XME camera; position end figures 53s.51, 10".4; UCAC-4 reference stars); 31.929, 14.6 (Federica Luppi and Luca Buzzi, Varese, Italy; 0.38-m f/6.8 reflector; position end figures 53s.54, 11".4; image posted at website URL http://www.astrogeo.va.it/pub/TOCP/PSN_N2554.jpg). W. Zheng, P. L. Kelly, I. Shivvers, K. I. Clubb, and A. V. Filippenko, University of California, Berkeley; and S. B. Cenko, Goddard Space Flight Center, report that a CCD spectrogram (range 350-1000 nm) of PSN J08175346+2328105 = SN 2013?? was obtained on Apr. 4.5 UT with the Shane 3-m reflector (+ Kast spectrograph) at Lick Observatory. The spectrum shows that 2013?? is an type-Ia supernova. Cross-correlation with a library of supernova spectra using the "SuperNova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) indicates a similarity with several normal type-Ia supernovae near maximum. The redshift estimated from SNID is z = 0.014, in good agreement with the value given in SIMBAD for NGC 2554; adopting this redshift, the rest-frame photospheric velocity, estimated from the minimum of the Si II 635.5-nm feature, is about 11400 km/s.
- Publication:
-
Central Bureau Electronic Telegrams
- Pub Date:
- November 2013
- Bibcode:
- 2013CBET.3729....1B