Supernova 2013ei in NGC 7068
Abstract
C. S. Kochanek, K. Z. Stanek, B. J. Shappee, J. Jencson, U. Basu, T. Holoien, J. F. Beacom, S. Villanueva, Jr., and A. Mosquera, Ohio State University; J. Brimacombe, Cairns, Australia; J. L. Prieto, Princeton University; D. Szczygiel and G. Pojmanski, Warsaw University Observatory; M. Dubberley, M. Elphick, S. Foale, E. Hawkins, D. Mullens, W. Rosing, R. Ross, and Z. Walker, Las Cumbres Observatory, report the discovery of a supernova during the ongoing All-Sky Automated Survey for SuperNovae (ASAS-SN) from V-band images taken with the double 14-cm "Brutus" telescope at Haleakala, Hawaii. SN 2013 UT R.A. (2000.0) Decl. Mag. Offset 2013ei June 26.47 21 26 31.93 +12 10 49.4 16.0 14" W, 6" S Nothing is visible at this position on images taken on June 22 or earlier (limiting V mag 17), though there were detections in two images on each of the nights of June 26 and 28. The ASAS-SN discovery images are posted at URL http://www.astronomy.ohio-state.edu/~assassin/followup/asassn13av.jpg, where the top-left panel shows the reference image, and the other three images show image-subtraction residuals. Confirming images taken with an infrared filter by Brimacombe with a 43-cm CDK telescope at Cairns are posted at URL http://www.astronomy.ohio-state.edu/~assassin/followup/asassn13av_confirm.jpg. A low-resolution spectrogram (range 385-685 nm) of 2013ei was obtained by Villanueva and Mosquera on June 29.5 with the OSMOS spectrograph mounted on the MDM 2.4-m telescope. The spectrum shows features characteristic of a type-Ia supernova around maximum light. A cross-correlation with a library of supernovae spectra via SNID (Blondin and Tonry 2007, Ap.J. 666, 1024) shows that the spectrum of 2013ei is consistent with a normal type-Ia around maximum (templates a few days before maximum also give good fits) at the redshift of its host galaxy, NGC 7068 (z = 0.0173). After correcting for the recession velocity of the host galaxy, a Si II 635.5-nm absorption velocity of -11500 km/s was measured.
- Publication:
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Central Bureau Electronic Telegrams
- Pub Date:
- July 2013
- Bibcode:
- 2013CBET.3602....1K