Messier 51 (NGC 5194), the Whirlpool Galaxy, is a face-on spiral galaxy located approximately 23 million light-yeas away in the constellation Canes Venatici and is one of the most well-known galaxies in the night sky. This galaxy has an apparent magnitude of 8.4 and has a radius of approximately 43,000 light-years. Its mass is estimated to be 160 billion times that of our Sun. M51 was discovered by Charles Messier on October 13, 1773 and its companion galaxy, NGC 5195, was discovered in 1781 by Pierre Mechain.
Telescope: Celestron 8” EdgeHD @ f/10
Accessories: Dew control by Dew Buster
Mount: Takahashi EM-200 Temma2
Camera: QSI583wsg CCD @ -10.0C
Guiding: Starlight Xpress Lodestar via PHD
Filters: Astrodon Tru-balance E-Series Generation II LRGB; Astrodon 5nm Ha
Exposure: 41 x 6min.(L); 9 x 20min.(Ha); 10 x 6min.(R); 10 x 6min.(G); 10 x 6min.(B); all frames binned 2x2
Acquisition: ImagesPlus Camera Control v4.3
Processing: Calibration, DDP in ImagesPlus 4.5b; Registration in RegiStar
Post-processing: ImagesPlus 4.5b; Adobe Photoshop CS5; Gradient Xterminator, Noise Ninja
Date(s): April 1, 2, 6 & 9, 2012
SQM reading (begin - end): N1:18.63 - 19.11; N2:17.38 - clouds; N3:?; N4:?
Temperature (begin - end): N1:70.7ºF - 63.7ºF; N2:74.7ºF - 67.1ºF; N3:54.9ºF - 42.8ºF; N4:67.0ºF - 55.0ºF
Capture conditions: N1 - transparency: Avg 3/5; seeing: Avg 3/5; N2 - transparency: Avg 3/5; seeing: Good 4/5; N3 - transparency: Above avg 4/5; seeing: Avg 3/5; N4 - transparency: Avg 3/5; seeing: Avg 3/5
Location: Hendersonville, TN, USA