ASAS-SN Discovery of A Bright Probable Supernova in the dwarf galaxy GALEXASC J025245.83-341850.6

ATel #6950; J. Brimacombe (Coral Towers Observatory), Subo Dong (KIAA-PKU), S. Kiyota (Variable Star Observers League in Japan), R. A. Koff (Antelope Hills Observatory), K. Z. Stanek, T. W.-S. Holoien, C. S. Kochanek, A. B. Danilet, 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), D. Szczygiel, G. Pojmanski (Warsaw University Observatory)
on 19 Jan 2015; 06:05 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 quadruple 14-cm "Cassius" telescope in Cerro Tololo, Chile, we discovered a new, bright transient source, most likely a supernova, in the galaxy GALEXASC J025245.83-341850.6:

Object      RA (J2000)     DEC (J2000)       Disc. UT Date   Disc. V mag 
ASASSN-15be  02:52:46.39   -34:18:52.52    2015-01-19.07    16.4

ASASSN-15be was discovered in images obtained on UT2015-01-19.07 at V~16.4. and it is also detected on 2015-01-15.15 at V~17.8. We do not detect (V>17.6) this object in images taken on UT 2015-01-12.10 and before.

See the ASAS-SN discovery image, An image obtained by J. Brimacombe on UT 2015-01-19.17 with the RCOS 51-cm telescope in New Mexico Skies Observatory confirms the discovery of the transient. This figure shows the archival DSS image of the host (left) and the J. Brimacombe's confirmation image (right). The red circle (10" radius) indicates the position of the transient in the J. Brimacombe's image.

The position of ASASSN-15be is approximately 7" from the center of the dwarf galaxy GALEXASC J025245.83-341850.6 (z=0.0219, d=88 Mpc, via NED), giving an absolute V-band magnitude of approximately -18.4 (m-M=34.7, A_V=0.054). Follow-up observations are encouraged.

We thank LCOGT and its staff for their continued support of ASAS-SN. ASAS-SN is supported in part by Mt. Cuba Astronomical Foundation. For more information about the ASAS-SN project, see the ASAS-SN Homepage and the list of all ASAS-SN transients.