2005IAUC.8631....1P

F. Patat and D. Baade, European Southern Observatory (ESO); L. Wang, Lawrence Berkeley Laboratory; S. Taubenberger, Max-Planck- Institut fuer Astrophysik, Garching; and J. C. Wheeler, University of Texas, report on observations of SN 2005ke (cf. IAUC 8630, CBET 289) on Nov. 16.12 UT with ESO's Very Large Telescope (+ FORS1 in polarimetric mode). A fully reduced spectrum (range 340-855 nm, resolution 1.3 nm FWHM) shows 2005ke to be an underluminous type-Ia supernova before maximum, showing the characteristic 420-nm Ti II and 635-nm Si II lines. The spectral appearance is very similar to that of SN 1999by at 4 days before maximum light (Garnavich et al. 2004, Ap.J. 613, 1120). The expansion velocities deduced from the absorption minima of Si II, Ca II and O I are all around 11400 km/s – with the exception of Ca II H and K, from which a velocity of 13300 km/s is deduced. The synthetic colors derived from the spectrum are B-V = +0.33 and V-R = +0.24. A preliminary reduction of the spectropolarimetric data indicates a polarization degree of several percent in the Ca II infrared triplet. SN 2005ke was re- observed on Nov. 17.11 with the same instrumentation; the velocities have decreased by about 400 km/s, the color became slightly redder (B-V = +0.45), and the polarization degree reduced by a factor of two. An earlier inspection of preliminarily reduced data led to the incorrect classification this object as a type-Ib/c supernova (cf. CBET 291).