Type Determination for SNe 2005dh and 2005di
ATel #581; A. Gal-Yam, D. Sand and D. Leonard (Caltech)
on 16 Aug 2005; 21:50 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Avishay Gal-Yam (firstname.lastname@example.org)
Subjects: Optical, Supernovae
A. Gal-Yam, D. Sand and D. Leonard report for the CCCP: We have observed SN 2005dh (Moore &Li ; IAUC # 8583 ) and SN 2005di (Pugh & Li; CBET #198) with the DBSP spectrograph mounted on the Hale 200" telescope at Palomar Observatory on 2005 August 14 UT. Reductions of the red-side spectra confirm that SN 2005dh is indeed of type Ia, with Si II (rest 635.5 nm) absorption indicating an expansion velocity v~16,000 km/s. If the object is indeed near maximum light, as reported by Salvo et al. (CBET #199), then this velocity is unusually high. The spectrum of SN 2005di is quite similar, also indicating this is a young SN Ia, with an expansion velocity of v~13,000 km/s, correcting for the galaxy redshift of z=0.025 (measured from narrow Balmer lines in the galaxy spectrum, and consistent with the cataloged value in NED).