Getting plate-solving status, please wait...

M100 & Vicinity, OSC (UHC-S), 12 May 2016

Technical card

Resolution: 790x607

Dates: May 12, 2016

Frames: 24x600"

Integration: 4.0 hours

Avg. Moon age: 6.20 days

Avg. Moon phase: 37.59% job: 1074429

Locations: Mapleton Lateral Observatory, Mapleton, Utah, United States


Another night of excellent conditions, and another chance to try the full automated, temperature-adjusted focusing routines, this time without the coma corrector (so everything should be a little easier, but I did have to establish the focus position for this combination). Meridian flip came pretty early and I don't yet know how to easily change the center of the field of view, so after flipping M100 was dead center and I had to manually reposition it where I wanted it. I'm still getting some drift that I think is flexure, but it wasn't as bad. Overall, I'm happy with the image, which I think is better than the one I got the last time I visited this field of view.

Date: 11-12 May 2016
Subject: M100
Scope: AT8IN
Filter: Baader Planetarium UHC-S
Mount: EQ-6 (EQMOD)+PEC
Guiding: Orion ST-80 + Antares 0.5x focal reducer + DSI Ic + PHD (Win 7 ASCOM)
Camera: DSI IIc, no chiller CCD 5 °C
Acquisition: Sequence Generator Pro with Nebulosity 4.0.4 ASCOM camera driver
Exposure: 24x600 s
Stacking: Neb 4, bad pixel map, bias included, 33 flats, match histograms, trans+rot align, Neb 4 40-60%tile stack.
Processing: StarTools 1.4.316: Crop; Wipe; Develop: 86.44%; HDR:Optimize; Color:Scientific, 200% saturation, red bias reduce 1.35; Deconvolute: 2.6 pix; Track: Smoothness 87%, 4.5 pix; Magic, shrink 1 pix. Photoshop CS6 + Astronomy Tools: Deep space noise reduction; Levels; Increase star color; layer masked unsharp mask to bring up contrast in dust lanes; Astroframe.



David Dearden


M100 & Vicinity, OSC (UHC-S), 12 May 2016, David Dearden