by Craig and Tammy Temple
M94 (NGC4736) is a colorful magnitude 8.99 spiral galaxy in the constellation Canes Venatici. What makes this galaxy interesting, is the presence of 2 ring structures. The inner ring appears to be an active star-forming region, while the outer may be an accretion disk. It was discovered in 1781 by Pierre Méchain and cataloged by Charles Messier only 2 days later.
Telescope: Celestron C8 Schmidt-Cassegrain
Accessories: Celestron f/6.3 reducer/corrector; Dew control by Dew Buster®
Mount: Orion Atlas EQ-G controlled by EQMOD
Guiding: Orion StarShoot AutoGuider on William Optics ZS66
Camera: Canon Digital Rebel T1i, Hap Griffin Baader modified
Filters: Astronomik CLS-CCD EOS Clip
Exposure: 101 x 180sec @ ISO 1600 (5hr. 3min.); 31 x 120sec @ ISO 400 (1hr. 2min.) for the core
Acquisition: ImagesPlus 3.82 Camera Control
Processing: ImagesPlus 3.80a – Calibrated, registered, averaged, DDP
Post-processing: Adobe Photoshop CS4; Gradient XTerminator; Noise Ninja
Date(s): March 18 & 23, 2010
Temperature(s): N1:58ºF (dropped to 54ºF); N2:59ºF (dropped to 50ºF)
SQM reading (begin - end): N1:n/a; N2:18.21 - 18.90
Moon data: n/a