Barred Spiral Galaxy in Pegasus



NGC7479: NGC 7479 is a magnitude 11.45 barred spiral galaxy, showing extensive spiral arms with newly formed stars and glowing clouds of gas. The galaxy is estimated to be about 100 million light-years from Earth and about the size of our own Milky Way Galaxy, approximately 100,000 light-years across. A long bar-shaped structure and spiral arms that are not symmetrical are visible in its central region. These unusual features are thought to be evidence that NGC 7479 is cannibalizing another galaxy in a merger that began perhaps 5 million years ago.


Technical Information:

LRGB: 225:30:30:54; L was 15 fifteen minute images; R and G consisted of 10 minute individual images; B consisted of 18 minute individual images. Luminance images unbinned; all others binned 2x2.

Equipment: 10" LX200 at f/12, and an SBIG ST-8XE camera/CFW-8 color filter wheel, guided with an SBIG AO-7, guiding at 7 Hz in Lum, 1-3 Hz in RGB.

Image Acquisition/Camera Control: CCDSoft V5.

Processing: All data calibrated (darks and dawn flats/flat darks) and registered in CCDSoft. Luminance layer average combined in Sigma; RGB average combined in CCDSoft. Luminance layer had one iteration of Richardson-Lucy applied in CCDSharp; color combine, curves, levels, unsharp mask, median filter and gaussian blurs applied in Photoshop.

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

Date: All images taken during the nights of 8/29/03, 8/31/03 and 9/1/03.

CCD Temperature: Luminance, -20C; RGB -25C

Moon Phase: First couple of days of cycle; no moon while imaging.

Pixel Scale: .61 arcseconds per pixel

Seeing: 2.6 arcsecond FWHM on single calibrated images.

Copyright 2003 Mark de Regt