Possible Dust Formation in SN 2006bc and the Detection of a New Optical Transient in NGC 2397

We present our analysis of SN 2006bc with Gemini/GMOS and HST optical imaging and spectroscopy from 200-695 days after explosion and Spitzer/IRAC imaging ranging from days 537 to 776. SN 2006bc was discovered in March 2006 in the star forming galaxy NGC 2397. It is surrounded by considerable nebulosity and differenced imaging of our HST and GMOS photometry reveal it to be a probable Type II-L with a minimum drop of nearly 3.5 magnitudes from peak luminosity to the beginning of the nebular phase. Analysis of its colors show it to be considerably redder than most normal SNe II likely due to substantial reddening within the host. We see evidence for dust formation in the SN ejecta in the form of a gradual blue-shifting of the H-alpha emission profiles due to condensing dust preferentially attenuation the redshifted emission. However, this new dust is not detected in Spitzer/IRAC data obtained on days 537, 679, and 776. We also report the discovery of a possible LBV in NGC 2397 that underwent an eruption sometime between 2006 October and 2007 February.