SUPERNOVA
2010ae IN ESO 162-17 G. Pignata and M. Cifuentes, Universidad
Andres Bello; J. Maza, M. Hamuy, R. Antezana, L. Gonzalez,
P. Gonzalez, P. Lopez, S. Silva, G. Folatelli, R. Cartier,
F. Forster, S. Marchi, and A. Rojas, Universidad de
Chile; B. Conuel, Wesleyan University; and D. Reichart,
K. Ivarsen, J. Haislip, A. Crain, D. Foster, M. Nysewander,
and A. LaCluyze, University of North Carolina at Chapel
Hill, on behalf of the CHASE project, report the discovery
of an apparent supernova (mag approximately 15.9 +/-
0.3) on an unfiltered image taken on Feb. 22.06 UT with
the 0.41-m 'PROMPT 3' telescope located at Cerro Tololo.
The new object, which is also present at mag approximately
15.6 +/- 0.3 in an image taken on Feb. 23.01, is located
at R.A. = 7h15m54s.65 +/- 0".1, Decl. = -57o20'36".9
+/- 0".1 (equinox 2000.0), which is about 0".6 east
and 0".2 south of the center of the galaxy ESO 162-17.
Nothing is visible at this position on archival images
taken on Feb. 10.11 and 17.11 (limiting mag 18.0). M.
Stritzinger, Las Campanas Observatory (LCO); G. Folatelli,
Universidad de Chile; G. Pignata, Universidad Andres
Bello; and M. M. Phillips, LCO, on behalf of the Carnegie
Supernova Project and the Millennium Center for Supernova
Science, report that they obtained an optical spectrum
(range 486-750 nm) of supernova 2010ae on Feb. 23.1
UT with the Gemini South telescope (+ GMOS).
This spectrum suggests that the object is a reddened
(the equivalent width of Na I D is 0.12 nm), peculiar
type-Ia event most similar to supernova 2006gz (Hicken
et al. 2007, Ap.J. 669, 17). The spectrum consists of
prevalent Si II (rest 635.5 nm) and S II (rest 544.9
and 562.3 nm) absorption features. In addition, a strong
absorption feature is present at 651 nm and a weaker
one at 718.1 nm, which is tentatively suggested to be
formed by C II (rest 658.0 and 723.4 nm). Adopting a
recession velocity of 1098 km/s (H I Parkes All-Sky
Survey Final Catalog; Wong et al. 2006, MNRAS 371, 1855)
for the host galaxy (ESO 162-17 is classified as a possible
type-Sb-peculiar), an approximate expansion velocity
of 4600 km/s was derived from the absorption minimum
of the Si II line (rest 635.5 nm).
A similar measurement of the C II feature (rest 658.0
nm) yields a blue-shift of 4300 km/s. Alternatively,
if the 651-nm feature was formed from H-alpha, an expansion
velocity of approximately 3600 km/s is obtained. |