Spiral Galaxy in Pisces



M74: This is a striking 10th magnitude galaxy in Pisces, approximately thirty million light years from Earth. It has a diameter of approximately 80,000 light years.


Technical Information:

LRGB: 490:120:120:90 (Luminance layer consists of data from 49 ten minute images, unbinned; R, G and B consist of ten-minute images, all binned 2x2).

Equipment: 12" RCX400 at f/8.5, and an SBIG ST-8XE camera/CFW-8 color filter wheel (Astrodon filter set), guided with an SBIG AO-7, guiding at 4 Hz for the luminance images, and 2Hz for color channels.

Image Acquisition/Camera Control: CCDSoft V5.

Processing: All images calibrated (darks and dawn flats) and registered in CCDSoft. Luminance layer average combined in Ray Gralak's Sigma Beta; color channels average combined in CCDSoft. One fast and fifteen slow (high frequency components only) iterations of Richardson-Lucy applied in AIP4WIN. Color combine, many careful adjustment of curves and levels, and selective Gaussian blurs and unsharp mask in Photoshop.

Location: My yard in Redmond, Washington, elevation 500'.

Date: Luminance images taken during the nights of 9/24, 9/26 and 9/27/2006; RGB images taken during the nights of 9/23, 9/24, 9/27 and 9/28/2006.

CCD Chip temperature: Some at -25C; others at -20C

Seeing: 2.4 arcsecond FWHM on typical calibrated image.

Transparency: Below average

Moon Phase: No moon during imaging

Copyright 2006 Mark de Regt

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