The NGC 70 Compact Galaxy Group is a compact group of galaxies (the eight NGC objects packed near the center of the image--but caveat whather NGC 68 is really part of the group, as discussed below), visually located in the constellation Andromeda. It is about 300 million light years from us. The many galaxies in the image (essentially, all the objects not obviously stars, either because they're elongated, or too fuzzy) not quite close to the center group are just other galaxies captured by my camera, and are not part of the group; there are a lot of galaxies in this universe!

For ease of reference, I have included a version of the image with many (but certainly not all) of the galaxies labeled; click on the image to toggle between the two versions.

NGC 68 has a different red shift than the others in the compact group at the center of the image, and isn't misshapen by gravitational forces among the galaxies; so it is thought that that galaxy likely is not part of the group, but merely in our line of sight.

This galaxy group bears a strong resemblance to the more-famousStephan's Quintet.

The entire field of the photo is about the same width as a full moon.

Technical Information:

LRGB: 525:150:180:240 (a total of over 18 hours of exposures); the luminance layer consists of blend of 31 fifteen-minute images using a luminance filter and 20 Three-minute images using a luminance filter; the R channel consists of 10 fifteen-minute images taken through a red filter; G consists of 12 fifteen-minute images taken through a green filter, while B is the combination of 12 twenty-minute images taken through a blue filter.

Equipment: RC Optical Systems 14.5 inch Ritchey-Chrétien carbon fiber truss telescope, with ion-milled optics and RCOS field flattener, at about f/9, and an SBIG STX-16803 with internal filter wheel (SBIG filter set), guided by an SBIG AO-X/STX Guider, all riding on a Bisque Paramount ME German Equatorial Mount.

Image Acquisition/Camera Control: Maxim DL, controlled with ACP Expert/Scheduler, working in concert with TheSky X.

Processing: All images calibrated (darks, bias and sky flats), aligned, and combined in Pixinsight. Color combine in Pixinsight. Some finish work (background neutralization, color calibration, Noise XTerminator and Blur XTerminator) done in Pixinsight; some finish work (LRGB combination, contrast and saturation adjustment) was done in Photoshop CC.

Location: Data acquired remotely from Sierra Remote Observatories, Auberry, California, USA.

Date: Images taken on many nights during November and December of 2023. Image posted June 14, 2024.

Date: Image scale of full-resolution image: 0.56 arcseconds per pixel.

Seeing: Generally very good, with individual luminance images having FWHM varying from 1.8 to 2.6 arcseconds.

CCD Chip temperature: -25C

Copyright 2023, 2024 Mark de Regt

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