SUNSET: 
0
Photographer:
KuriousGeorge
Location of Photo:
Julian, CA
Date/Time of photo:
December 6, 2023
Equipment:
Planewave CDK24
Description:
Here's another example of "the calm before the storm". As soon as I saw the PHD tracking line nearly flat, I knew this was going to be a good night. (-: Here the 59 5-minute luminance subs have FWHM between 1.37" and 2.43" with a 1.9" average. I rarely see FWHM average less than 2". Unfortunately the calm ended the next two days with wind gusts up to 40 mph and FWHM > 4". )-: RGB is from my September 2018 capture under 21.5 SQM skies. Color uses the latest PI Spectrophotometric Color Calibration. "NGC 891 (also known as Caldwell 23, the Silver Sliver Galaxy, and the Outer Limits Galaxy) is an edge-on unbarred spiral galaxy about 30 million light-years away in the constellation Andromeda. It was discovered by William Herschel on October 6, 1784. The galaxy is a member of the NGC 1023 group of galaxies in the Local Supercluster. It has an H II nucleus. NGC 891 looks as the Milky Way would look like when viewed edge-on. Some astronomers have even noted how similar to NGC 891 our galaxy looks as seen from the Southern Hemisphere and, in fact, both galaxies are considered very similar in terms of luminosity and size. Studies of the dynamics of its molecular hydrogen have also proven the likely presence of a central bar. Despite this, its dusty disk show unusual filamentary patterns. These patterns are extending into the halo of the galaxy, away from its galactic disk. Scientists presume that supernova explosions caused this interstellar dust to be thrown out of the galactic disk toward the halo. It may also be possible that the light pressure from surrounding stars causes this phenomenon."
