Type Determination for SN 2005ac
ATel #408; The Nearby Supernova Factory: G. Aldering, B. C. Lee, S. Loken, P. Nugent, S. Perlmutter, J. Siegrist, R. Scalzo, R. C. Thomas, L. Wang (Lawrence Berkeley National Laboratory, Berkeley, CA), G. Adam, R. Bacon, C. Bonnaud, L. Capoani, D. Dubet, F. Henault, B. Lantz, J-P. Lemonnier, A. Pecontal, E. Pecontal (Centre de Recherche Astronomique de Lyon), N. Blanc, G. Boudoul, S. Bongard, A. Castera, Y. Copin, E. Gangler, L. Sauge, G. Smadja (Institut de Physique Nucleaire de Lyon), R. Kessler (Kavli Institute for Cosmological Physics, Chicago, IL), P. Antilogus, P. Astier, E. Barrelet, G. Garavini, S. Gilles, L-A. Guevara, D. Imbault, C. Juramy, R. Pain, R. Taillet, D. Vincent (Laboratoire de Physique Nucleaire et de Haute Energies de Paris), C. Baltay, D. Rabinowitz, A. Bauer (Yale)
on 10 Feb 2005; 20:22 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Peter Nugent (penugent@lbl.gov)
Subjects: Optical, Supernovae
A spectrum (range 330-990 nm) of SN 2005ac in SDSS J133955.93+005217.1 (Burket and Li, IAUC # 8478 ), obtained on Feb 10.65 UT with the SuperNova Integral Field Spectrograph on the University of Hawaii 2.2m telescope, reveals it to be a Type Ia supernova approximately one week past maximum light. The supernova is similar to SN 2001ay (Nugent et al., IAUC # 7612 ), with very strong Si II absorption features throughout the optical spectrum. Adopting the SDSS redshift of 0.070 for the host galaxy, the supernova expansion velocity is approximately 11,700 km/s for Si II (rest 635.5 nm).