I wanted to have at least 3 hours of M101 and had hoped for 5 hours but ended up with 3.5 hours. If it wasn’t for Dan’s help, it would have probably been worse. For some reason, the Lodestar was no longer par-focal. It took us about 90 minutes to figure a combination of extensions and adapters that worked. Despite some artefacts on the guiding image (probably due to some defects in the prism) guiding was perfect. I sticked with 10 mn exposures for the whole night considering there shouldn’t be any over-exposed area with this target.
Processing was pretty challenging because of some problems during calibration and the fact I think my subs were colder than my darks by about 3-4 C. I need to shoot more 10mn darks in the 8-10C temperature range.
Update (2012/06/02): If you look closely to the right hand side of the galaxy core you will spot the remnant from last year’s supernova in M101. It’s actually stands out from the rest of the image pretty well with a very distinct/unique blue cyan tone. Pretty cool :)
- Date: May 19th 2012
- Camera: Canon 500D Baader Modified and CP30T-EOS Cooled (Sensor maintained at 10 C – Exif temperature: 10 C)
- ISO: 1600
- Exposures: ~ 3.5 hours of integration time (600 s subs)
- Mount: Losmandy G11 Gemini 2
- Imaging Telescope: AT8RC w/ AP-CCDT67 @ .68x
- Guiding: OAG9 w/ SX Lodestar
- Calibration: Darks, Flats, Bias
- Stacking: DSS (Sigma/Kappa)
- Final blending/processing: PixInsight 1.7 and Adobe Photoshop CS5