January 21, 2012: In IAU Central Bureau Electronic Telegram 2974 (Daniel W. E. Green, ed.), B. Moore, J. Newton, and T. Puckett report the discovery of an apparent supernova in the irregular galaxay NGC 3239 at unfiltered magnitude 14.6 taken with a 0.40-m reflector at Portal, AZ, on 2012 Jan. 7.3869 UT in the course of the Puckett Observatory Supernova Search. SN 2012A was confirmed by Puckett at magnitude 14.4 on Jan. 8.3352; nothing is visible down to magnitude 19.0 on his images from 2011 Dec. 29. The discoverers have posted an image at URL http://www.possdata.com/PSNJ10250739+1709146.jpg. The variable was named PSN J10250739+1709146 when it was posted at the Central Bureau's TOCP webpage.
Coordinates: R.A. 10 25 07.39, Decl. +17 09 14.6 (equinox 2000.0) which is 25" east and 16" south of the center of NGC 3239.
SN 2012A has been designated a Type-II supernova discovered a few days before maximum, according to spectroscopy by T. Pursimo (reported by V. Stanishev, Centro Multidisciplinar de Astrofisica, Instituto Superior Tecnico, Lisbon, et al.), obtained on 2012 Jan. 10.145 UT (CBET 2974); by Y. Cao, California Institute of Technology, M. M. Kasliwal, Observatories of the Carnegie Institution for Science and Princeton University, G. Wallerstein and A. Ritchey, University of Washington, D. A. Howell, Las Cumbres Observatory Global Telescope and University of California at Santa Barbara, et al., obtained on 2012 Jan. 10.275 UT (CBET 2975, Daniel W. E. Green, ed.); and by Rupak Roy, Aryabhatta Research Institute of Observational Sciences, Nainital, and Sayan Chakraborti, Tata Institute of Fundamental Research, Mumbai, et al., obtained on 2012 Jan. 10 (CBET 2975).
Additional observations reported on CBET 2974 by F. Luppi and Luca Buzzi (Varese, Italy), T. Yusa (Osaki, Japan), Hidetaka Sato (Ota-ku, Tokyo, Japan), Robert Koff (Bennett, CO), Joseph Brimacombe (Cairns, Australia), and Gyula M. Szabo (MTA Konkoly Observatory, Piszkesteto, Hungary), and to the AAVSO by Michael Simonsen (Imlay City, MI), Klaus Wenzel (Grossostheim, Germany), Gustav Holmberg (Lund, Sweden), Frank Melillo (New York), Richard Tyson (Freeport, NY), Philip Steffey (Daytona Beach, FL), Massimiliano Martignoni (Magnago, Italy), and Robert Wahlstrom (Alingsas, Sweden) indicate that SN 2012A has brightened to 13.725 V as of 2012 Jan 20.2699 UT.
Finder charts may be created using VSP (http://www.aavso.org/vsp).
Observations should be reported to the AAVSO International Database using the name SN 2012A.
Congratulations to B. Moore, J. Newton, and T. Puckett on their discovery!
This AAVSO Special Notice was compiled by Elizabeth O. Waagen.
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