Getting plate-solving status, please wait...
M101, Pinwheel Galaxy, 5 Jun 2014, David Dearden

M101, Pinwheel Galaxy, 5 Jun 2014

Equipment

Loading...

Acquisition details

Loading...

Description

20.9 ± 1.8 million LY

Light wind gusts again. Had some trouble getting the mount to settle down and track after doing the goto. This may be because I started with the scope on the east side of the meridian; I almost always start with it on the west. I'm using the "lowpass" DEC guiding algorithm again. Guiding looks like it might be quite good if the wind would settle down. Hopefully what I'm seeing now is the evening canyon breeze and it will diminish as the night progresses. After 8 or so subframes, I noticed the connection through the USB-Serial port to the PicGoto had dropped. I've never seen that happen before without also losing the cameras (because of a loose USB connection), so I got to see what it looks like when you are not guiding at all. It looks pretty bad with my mount! Chiller running at 2.5 A, 6 °C on the CCD; it dropped to -2 °C by morning and I had ice all over the outside of the camera. All in all, despite the wind gusts I was able to keep most of my subframes. This is significantly better than last year's image, so I'm satisfied, although I'd always love for the image to be sharper.

From the shape of this galaxy and the streams of stars (particularly along the bottom of the image) I’d guess this guy has undergone at least one collision with another galaxy of significant mass.

In the revision, I applied CS6 Levels to darken out some of the anomalous color haze.

Date: 5 Jun 2014

Subject: M101, Pinwheel Galaxy

Scope: AT8IN + HPS Coma Corrector

Filter: None

Mount: CG-5 (Synta motors, PicGoto Simplificado)

Guiding: 9x50 Finder/Guider + DSI Ic + PHD 2.2.2 (Win 7 ASCOM)

Camera: DSI IIc chiller at 2.50 A, 6 to -2.0 °C

Acquisition: Nebulosity 3.2.0, no dither

Exposure: 60x300 s

Stacking: Neb 3, bad pixel map, bias included, normalize first, trans+rot align, 1.5 SD stack.

Processing: StarTools 1.3.5.279 Crop; Wipe:Color & brightness 76%; Develop 90.05%; HDR:Reveal core (for one layer); HDR Optimize soft (for another layer); Color:Scientific, 300% sat.; Deconvolute auto mask 2.5 pix; Track RNC 40.69%; Magic:Shrink 1 pix. CS6 Astronomy Tools layer the “core reveal” layer at 50% transparency on top of the “optimize soft” layer; Healing brush; increase star color; Deep space noise reduction; Less crunchy more fuzzy; Make stars smaller; Astro Frame.

Comments

Revisions

  • M101, Pinwheel Galaxy, 5 Jun 2014, David Dearden
    Original
  • Final
    M101, Pinwheel Galaxy, 5 Jun 2014, David Dearden
    B

Histogram

M101, Pinwheel Galaxy, 5 Jun 2014, David Dearden