Spiral Galaxy in Andromeda



NGC891: This is an 11th magnitude spiral galaxy in Andromeda, presenting to us edge-on. The prominent dust lanes seem to bisect the disc, as well as sending fine "fingers" out from the center. It is thought by some to be a barred spiral galaxy. It is estimated to be approximately 20 million light years from earth, and approximately 120,000 light years in diameter


Technical Information:

LRGB: 200:90:60:144 (Luminance imagess all ten minute images, unbinned; R & G were 10 minute images, binned 2x2; B were 16 minute images, binned 2x2).

Equipment: 10" LX200 at f/12 and SBIG ST-8E camera/CFW-8 color filter wheel, guided with an SBIG A0-7, guiding at 11 Hz in Lum, 1.9-4 Hz in the color images.

Image Acquisition/Camera Control: CCDSoft V5.

Processing: All images calibrated (darks and dawn (fog) flats) and registered in AIP4WIN. All layers average combined in Ray Gralak's Sigma Reject package. Color combine, adjustment of curves and levels, unsharp mask and gaussian blurs performed in Photoshop 6.

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

Date: Luminance images taken during the night of October 11, 2002. R, G and B taken during the nights of 10/12/02 and 10/13/02.

CCD Temperature: Luminance layer: -30C; R, G and B: -28C

Moon Phase: Days 5, 6 and 7 (last three days of the first quarter moon).

Seeing: 2 Arcsecond FWHM

Copyright 2002 Mark de Regt