SN2011dh | Rod Pommier

Rod Pommier
Location of photo
Pommier Observatory, Portland, OR, USA
Date/Time of photo
2011-05-08 and 2011-06-15
Celestron Compustar C14 telescope with 0.75x focal reducer (f/8). SBIG STL 11000M CCD at -25C,self-guided. Baader Planetarium LRGB filters. Left image: LRGB exposures=184:70:70:70 minutes=7hours:O4minutes total exposure.Calibrated with bias, dark, and flat field frames Right image: Same supplemented with LRGB=44:44:44:40 minutes=2hour:52minutes additional exposure.
M51, the Whirlpool Galsxy, and NGC 5195 before and after supernova SN2001dh. The left image is a 7hour:4minute LRGB exposure taken the month before the supernova appeared. The right image was composed by adding additional exposure time of LRGB=44:44:44:40minutes after the supernova appeared.