Polar Ring Galaxy in Pisces

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NGC660 is a moderate-sized polar ring galaxy, about 45 million light years distant. The ring outside the main part of the galaxy is about 50,000 light years across (less than half the diameter of our Milky Way galaxy).

The first polar ring galaxy was not discovered until 1978; it is theorized that these strange objects are the result of a collision between two galaxies, with the larger capturing the smaller and being re-formed by the gravitation forces.

There is a high level of star-formation taking place in the ring, an expected result of gravitational interaction between galaxies.

As usual, there are a lot of background galaxies in this photo, headlined by IC148 (in the lower left corner of this photo), a small irregular galaxy perhaps 35 million light years distant. The entire field of the photo is about the same width as a full moon.


Technical Information:

L(HaR)GB: 480:360:180:180:240 (a total of 24 hours of exposures); luminance layer consists of blend of 32 fifteen-minute images using a luminance filter; R channel is a blend of the Ha data (18 twenty-minute images) and 15 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, deconvolution, gradient removal, HDR Multiscale Transform for noise reduction and sharpening, and blending the Ha data into the red channel and the luminance layer) done in Pixinsight; some finish work (Neat Image noise reduction, 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 October of 2021. Image posted November 28, 2021.

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

Seeing: Generally poor, and lots of nights were marred by smoke from nearby wild fires

CCD Chip temperature: -25C

Copyright 2021 Mark de Regt

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