Focal Pointe Observatory
Astrophotography by Bob Franke

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NGC 520

 

Click the image for a 70% size wide field view. (2700 x 1800 - 2.40 MB)

Instrument

12.5" RCOS @ ~ f/9 (2880 mm fl) at 0.64 arcsec/pixel. Shown at  0.91 arcsec/pixel.

Mount

Paramount ME

Camera

SBIG STL-11000 w/ FW8 filter wheel & AstroDon Gen-2 LRGB filters.

Acquisition Data

12/2/2016 to 12/29/2016 Chino Valley, AZ. with CCD Commander & CCDSoft.  AOL guided

Exposure

Lum

 450 min (15 x 30 min. each) Bin 1x1

RGB

 540 min (12 x 15 min. each) Bin 2x2

Software & Processing Notes

 

  • CCDSoft, CCDStack, PixInsight, Photoshop CS6.

  • eXcalibrator v6.2 for (g:r),(b:r) color balancing, using 45 stars from the SDSS-DR12 database.

  • CCDBand-Aid to repair KAI-11000M vertical bars.

  • CCDStack to calibrate all sub exposures and Maximum Entropy deconvolution of the galaxy core.

  • PixInsight processing includes CosmeticCorrection, data  rejection, mean combine all the sub-exposures, create the LRGB image, gradient removal and non-linear stretching with HistogramTransformation.

  • PhotoShop for additional background neutralization and background smoothing.

  • Noiseware 5, a PhotoShop plug-in.

Comment

 

North is to the left.

NGC 520 is a pair of colliding spiral galaxies about 88 million light-years away in the constellation Pisces. William Herschel discovered the pair on December 13, 1784. The two galaxies began to emerge about 300 million years ago. Spectral analysis shows two separate velocity systems with two nuclei and two small tales.

 

To the right is the dwarf galaxy UGC 957, at a distance of 82 million light years. The above image shows a large faint tidal tail extended northward and curving boards UGC 957. Some simulations suggest that UGC 957 was a satellite of one of the original two colliding galaxies that make up NGC 520.

 

Additionally, the image has at least 3000 visible background galaxies and nine visible quasars.