ASAS-SN Discovery of A Probable Supernova in NGC 3449

ATel #6886; Subo Dong (KIAA-PKU), A. B. Davis, T. W.-S. Holoien, K. Z. Stanek, C. S. Kochanek, G. Simonian, U. Basu, N. Goss, J. F. Beacom (Ohio State), B. J. Shappee (Hubble Fellow, Carnegie Observatories), J. L. Prieto (Diego Portales; MAS), D. Bersier (LJMU), P. R. Wozniak (LANL), J. Brimacombe (Coral Towers Observatory), D. Szczygiel, G. Pojmanski (Warsaw University Observatory)
on 8 Jan 2015; 14:08 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Subo Dong (dongsubo@pku.edu.cn)

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During the ongoing All Sky Automated Survey for SuperNovae (ASAS-SN or "Assassin"), using data from the double 14-cm "Cassius" telescope in Cerro Tololo, Chile, we discovered a new transient source, most likely a supernova, in the galaxy NGC 3449:

Object      RA (J2000)     DEC (J2000)         Disc. UT Date   Disc. V mag 
ASASSN-15aj  10:52:53.26    -32:55:34.86     2015-01-08.3     15.0

ASASSN-15aj was discovered in images obtained on UT 2015-01-08.3 at V~15.0 mag. It was also detected on UT 2015-01-01.3 at V~16.7, UT 2015-01-03.2 at V~15.7 mag and UT 2015-01-04.3 at 16.0 mag. We do not detect (V>17.5) the object in images taken on UT 2014-12-30.2 and before. An image obtained by LCOGT 1.0m A in Dome A at Cerro Tololo on UT 2015-01-08.3 confirms the discovery of the transient. This figure shows the archival DSS image of the host (left) and the LCOGT V-band confirmation image (right). The red circle has a radius of 5.0" and is centered on the position of the transient in the LCOGT image.

The position of ASASSN-15aj is approximately 3.8" North and 5.1" West from the center of the galaxy NGC 3449 (z=0.010921, d=47 Mpc, via NED), giving an absolute V-band magnitude of approximately -18.5 (m-M=33.3, A_V=0.2). Follow-up observations are encouraged.

We thank LCOGT and its staff for their continued support of ASAS-SN. For more information about the ASAS-SN project, see the ASAS-SN Homepage and the list of all ASAS-SN transients.