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BVRI Photometry of SN 2011fe in M101


Michael W. Richmond

Physics Department, Rochester Institute of Technology, 84 Lomb Memorial Drive, Rochester, NY, 14623

Horace A. Smith

Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824

Received March 19, 2012; revised April 4, 2012; accepted April 11, 2012


We present BVRI photometry of Supernova 2011fe in M101, starting 2.9 days after the explosion and ending 179 days later. The light curves and color evolution show that SN 2011fe belongs to the “normal’’ subset of type Ia supernovae, with a decline parameter Delta m15(B) = 1.21 ± 0.03 mag. After correcting for the small amount of extinction in the line of sight, and adopting a distance modulus of (m – M) = 29.10 mag to M101, we derive absolute magnitudes MB = –19.21, MV = –19.19, MR = –19.18, and MI = –18.94. We compare the voluminous record of visual measurements of this event to our CCD photometry and find evidence for a systematic difference which depends on color.

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