------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 2850 2012 Aug 21 14.46UT Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise, Basingstoke, Hants, RG22 4PP,England.Telephone/FAX(01256)471074Int:+441256471074 INTERNET: GUY@TAHQ.DEMON.CO.UK Backup: gmh@wdcc1.bnsc.rl.ac.uk WORLD WIDE WEB http://www.theastronomer.org ------------------------------------------------------------------- OGLE-2012-NOVA-01 S. Kozlowski (Warsaw Observatory) et. al., and others report on 'The Astronomer's Telegram 4323' their discovery of a relatively bright (I=12.5 mag near the peak) possible classical nova in the database of new objects from the fourth phase of the OGLE survey (OGLE-IV). The nova does not have a detectable progenitor in the OGLE-IV I-band images before 2012 May 2, meaning it was fainter than I>20.2 mag. Its brightness rose fast after 2012 April 24 (no detection on the image) reaching I=14.96 mag on 2012 May 2 and peaking on 2012 May 5 with I=12.53 mag. We then observed a slow magnitude decline, reaching approximately I=17 mag as of Aug 21. The location of the nova is: RA 17:56:49.39 DEC -27:13:28.2 (2000), 1 arcsec from a faint I=18.99 mag star, that securely is not the progenitor. There exist three OGLE-IV V-band images from 2012 season for this field. Only the third one, taken on 2012 July 25 was recorded during the eruption but we find no detection of the nova at the level of V>21.2 mag. This corresponds to the colour of (V-I)>~5.1 mag or the extinction corrected colour of (V-I)>~1.6 mag (see below). Using the VVV extinction map, we find extinctions in V- and I-band to be A_V=6.8 mag and A_I=3.3 mag assuming the standard interstellar extinction law with R_V=3.1. This amount of extinction shifts the red clump giant stars to V=~22.1 mag, i.e., below the OGLE-IV detection limit. The I-band extinction corrected near peak magnitude would be then I=9.2 mag, what corresponds approximately to the absolute magnitude of M_I=-5.3 mag assuming the nova exploding in the Galactic bulge (at 8 kpc). SUPERNOVA 2012dy IN PGC 66545 (PETER MARPLES) 2012dy Aug 3.53 21 18 50.70 -57 38 42.5 15.6R 2.3"W 17 "S D. Milisavljevic: spectrum Aug 5 (10-m SALT) type-II not long after outburst. SUPERNOVA 2012dz IN NGC 6619 (ITALIAN SS PROJECT) 2012dz Aug 8.06 18 18 56.2 +23 39 37.0 16.5 11 "E 17 "N Additional CCD magnitude: Aug 7.61, 16.6 (D. Denisenko and V. Lipunov, 0.40-m f/2.5 MASTER Amur robotic telescope + 16-megapixel camera; pre-discovery; position end figures averaged from two exposures are 56s.00, 32".9). L. Tomasella: spectrum Aug 8 type-Ia, a few days after B=maximum. SUPERNOVA 2012ea IN NGC 6430 (LOSS) 2012ea Aug 8.29 17 45 10.40 +18 08 26.8 16.8 55.3"W 7.0"N L. Tomasella: spectrum, Aug 8, 1991bg-like type-Ia supernova a few days before maximum. Adopting the discovery magnitude of 17.3, a Virgo-corrected distance modulus of mag 33.23 and a Milky Way absorption of 0.14 mag, the supernova would have an absolute magnitude of about -16.1, making it one of the faintest 1991bg-like supernovae known. SUPERNOVA 2012eb = GRB 120714B (SWIFT) A gamma-ray burst designated GRB 120714B was announced on GCN Circular 13471 by C. J. Saxton as detected on July 14.888 UT by the Swift Burst Alert Telescope at: RA 23h41m38s.35, DEC -46 11.07' (2000). Spectroscopy of the optical transient performed on Aug. 1/2, or 18.3 days after the burst suggests a supernova of type Ib or Ic. Guy M Hurst