Supernova 2004ef in UGC 12158
Abstract
G. Folatelli, Las Campanas Observatory, together with M. Hamuy and N. Morrell, on behalf of the Carnegie Supernova Project, report that two optical spectra (range 400-730 nm) of SN 2004ef (cf. IAUC 8399), taken by W. Krzeminski on Sept. 7.16 UT with the Las Campanas 2.5-m du Pont telescope (+ Modular Spectrograph) and by J. Maza and E. Treister on Sept. 8.18 with the 6.5-m Clay telescope (+ Boller & Chivens Spectrograph), reveal that this is a type-Ia supernova, supported by the presence of Si II at 635.5, 413.0, and 597.2 nm and by S II at 545.4 and 564.0 nm. Similar spectral features have been observed in spectra of the normal type-Ia supernovae 1994D and 1999ee at 10 days before maximum, which suggests an early phase for 2004ef. The minimum of the Si II 635.5-nm line yields high expansion velocities of 16200 and 14500 km/s on each night, respectively, assuming the NED host-galaxy recession velocity of 9290 km/s. An upper limit of 0.05 nm is given to the equivalent width of the interstellar Na I D line, indicating a low reddening by dust in the host galaxy.
- Publication:
-
International Astronomical Union Circular
- Pub Date:
- September 2004
- Bibcode:
- 2004IAUC.8403....2F