Celestial hemisphere:  Northern  ·  Constellation: Canes Venatici (CVn)  ·  Contains:  M 94  ·  NGC 4736
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M94, Croc's Eye Galaxy, 11 May 2013, David Dearden
M94, Croc's Eye Galaxy, 11 May 2013
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M94, Croc's Eye Galaxy, 11 May 2013

Equipment

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Acquisition details

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Description

The Croc's Eye Galaxy is easy to find because it is close to Cor Caroli, which can be used to line up the Telrad. From there, I recognized asterisms in the finder and walked my way up to the galaxy. Once I was there, it is bright enough to easily see in the finder at 1.5 s and in the imager at 1 s. Chiller running at 6.8 V 1.7 A, 7.5 °C. Some light wind gusts tonight and a few scattered clouds, but otherwise the night looks good. The wind caused a lot of subs to be thrown out, but this is still a better image than I got last year. Last year's attempt was a year to the day ago.

In the B revision, I deliberately blurred the stars in processing because I was trying to blur out noise and preserve the outer halo of the galaxy. It didn’t really work, but I like this look for the galaxy a bit better.

In the C revision, I’ve used layer masking a lot to sharpen the core and show a little of the outer halo without introducing a lot of the noise that is really there, so I kept the sharp stars and the sharp core both this way.

Date: 11 May 2013

Subject: M94, The Croc’s Eye Galaxy

Scope: AT8IN + HPS Coma Corrector

Filter: None

Mount: CG-5 (Synta motors)

Guiding: 9x50 Finder/Guider + DSI Ic + PHD 1.14.2

Camera: DSI IIc (chiller at ~1.7 A, T = 7.5 °C)

Acquisition: Nebulosity 3.1.5, no dither

Exposure: 19x300 s

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

Processing: StarTools 1.3 Crop; Wipe:Color & Brightness; Develop 92.47%; HDR:Equalize; Sharpen; Deconvolute: 3.0 pix; Track; Color:Bottom 2.0, Top Full, Sat 645%; Repair:Redistribute core average, Magic:Shrink 1; Magic:Tighten 1 (large stars only); Denoise; Life:Moderate. CS6+Astronomy Tools deep space noise reduction; increase star color; layer mask levels; 2 levels of layer mask unsharp mask on dust lanes; less crunchy more fuzzy; AstroFrame.

Comments

Revisions

  • M94, Croc's Eye Galaxy, 11 May 2013, David Dearden
    Original
  • M94, Croc's Eye Galaxy, 11 May 2013, David Dearden
    B
  • Final
    M94, Croc's Eye Galaxy, 11 May 2013, David Dearden
    C

Sky plot

Sky plot

Histogram

M94, Croc's Eye Galaxy, 11 May 2013, David Dearden