ASAS-SN Discovery of Two Probable Supernovae in 2MASX J23320747-4116097 and GALEXASC J010647.95-465904.1
ATel #6809; S. Kiyota (Variable Star Observers League in Japan), T. W.-S. Holoien, K. Z. Stanek, C. S. Kochanek, A. B. Davis, G. Simonian, U. Basu, N. Gross, J. F. Beacom (Ohio State), B. J. Shappee (Hubble Fellow, Carnegie Observatories), J. L. Prieto (Diego Portales; MAS), D. Bersier (LJMU), Subo Dong (KIAA-PKU), P. R. Wozniak (LANL), J. Brimacombe (Coral Towers Observatory), D. Szczygiel, G. Pojmanski (Warsaw University Observatory), E. Conseil (Association Francaise des Observateurs d'Etoiles Variables), J. Nicolas (Groupe SNAUDE, France)
on 12 Dec 2014; 18:13 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Thomas Holoien (firstname.lastname@example.org)
Subjects: Optical, Supernovae, Transient
Referred to by ATel #: 6882
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 two new transient sources, most likely supernovae, in the galaxies 2MASX J23320747-4116097 and GALEXASC J010647.95-465904.1:
Object RA (J2000) DEC (J2000) Disc. UT Date Disc. V mag
ASASSN-14lv 23:32:07.37 -41:16:11.76 2014-12-12.05 17.2
ASASSN-14lw 01:06:49.17 -46:58:59.96 2014-12-12.07 16.5
ASASSN-14lv was discovered in images obtained on UT 2014-12-12.05 at V~17.2 mag. We do not detect (V>16.8) the object in images taken on UT 2014-12-08.06 and before. An image obtained by S. Kiyota on UT 2014-12-12.54 using a 0.5m CDK + FLI PL-9000 at the ITelescope.NET site at Siding Springs Observatory confirms the discovery of the transient. This figure shows the archival DSS image of the host (left) and the S. Kiyota confirmation image (right). The red lines indicate the position of the transient in the S. Kiyota image.
The position of ASASSN-14lv is approximately 2.2" South and 1.0" West from the center of the galaxy 2MASX J23320747-4116097 (z=0.049194, d=206 Mpc, via NED), giving an absolute V-band magnitude of approximately -19.4 (m-M=36.57, A_V=0.057). At this distance, ASASSN-14lv is the furthest SN candidate discovered by ASAS-SN to date.
ASASSN-14lw was discovered in images obtained on UT 2014-12-12.07 at V~16.5 mag. We do not detect (V>16.9) the object in images taken on UT 2014-12-08.08 and before. An image obtained by S. Kiyota on UT 2014-12-12.55 using a 0.5m CDK + FLI PL-9000 at the ITelescope.NET site at Siding Springs Observatory confirms the discovery of the transient. This figure shows the archival DSS image of the host (left) and the S. Kiyota confirmation image (right). The red circle has a radius of 5" and is centered on the position of the transient in the S. Kiyota image.
The position of ASASSN-14lw is approximately 3.5" North and 12.0" East from the center of the galaxy GALEXASC J010647.95-465904.1, which has no redshift available in NED. We also note that the transient lies within the galaxy cluster 0105.1-4708, with z=0.0230. If indeed originating from this cluster, ASASSN-14lw would have a V-band absolute magnitude of approximately -18.56 (m-M=35.02, A_V=0.038).
Follow-up observations of both transients, particularly spectroscopy, 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.