by Craig and Tammy Temple
M108 (NGC3556) is a magnitude 10.20 barred spiral galaxy in the constellation Ursa Major. From Earth, we are viewing this galaxy edge-on. It was discovered in 1781 by Pierre Méchain.
Telescope: Celestron C8 Schmidt-Cassegrain
Accessories: Celestron f/6.3 reducer/corrector; Dew control by DewBuster
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: 82 x 180sec @ ISO 800 (4hr. 6min.)
Acquisition: ImagesPlus 3.82 Camera Control
Processing: ImagesPlus 3.80a – Calibrated, registered, averaged, DDP
Post-processing: Adobe Photoshop CS4; Gradient XTerminator; Noise Ninja, Noel Carboni's Tools
Date(s): February 25, 2010
Temperature(s): 32ºF (dropped to 25ºF)
SQM reading (begin - end): 17.01 - 17.20
Moon data: Waxing gibbous, 90% illumination, 50º angular separation from target