2005IAUC.8610....3M

M. Modjaz, R. Kirshner, and P. Challis, Harvard-Smithsonian Center for Astrophysics, report that a spectrogram (range 350-740 nm) of SN 2005eq (cf. IAUC 8608), obtained by M. Calkins on Oct. 2.05 UT with the Mt. Hopkins 1.5-m telescope (+ FAST), shows it to be a peculiar type-Ia supernova with a spectral-feature age (Riess et al. 1997, A.J. 114, 722) of about 3 (± 2) days before maximum light. The spectrum exhibits a blue continuum and a shallow Si II (rest 635.5 nm) absorption, as well as strong Fe III features observed at 500 and 431 nm. The spectrum is similar to those of SN 1998es (IAUC 7054) and SN 1999dq (IAUC 7250) at 3 days before maximum; this might imply that SN 2005eq will have a slow declining lightcurve. Adopting the NED recession velocity of 8687 km/s for the host galaxy (from the Sloan Digital Sky Survey 2003), the supernova expansion velocity derived from the Ca II H+K absorption (rest 394.5 nm) is about 19900 km/s – and from the Si II absorption (rest 635.5 nm) is about 8500 km/s.