Arp 271 - Interacting Galaxies: NGC 5426 & NGC 5427
Date: June 16, 2020
Cosgrove’s Cosmos Catalog ➤#0034
Arp 271 - two gravitationally interacting galaxies - NGC 5426 & NGC 5427 (click to enlarge)
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About the Target
Arp 271 consists of two distant spiral galaxies, NGC 5426 & NGC 5427) that are interacting and gravitationally linked. The galaxies are located a whopping 130 Million light-years from earth, in the cancellation of Viro. Both galaxies are of a similar size and have been interacting for millions of years, and they will continue to for millions more. It is not known whether they will collide or not. But we do know that the mutual gravitational attraction has created "bridges" of stars, gas, and dust between them.
The Arp designation refers to "The Atlas of Peculiar Galaxies," a catalog of peculiar galaxies produced by Halton Arp in 1966.
More can be learned about this catalog HERE.
The Annotated Image
Annotated version of Arp 271 - created with Pixinsight ImageSolve and AnnotateImage scripts.
The Location in the Sky
IAU/Sky & Telescope Constellation Map for Virgo - Arp 271 is indicated with the yellow arrow.
About the Project
This is a small and faint object and not the best for my telescope, which is optimized for larger-scale targets, but I wanted to try something that was a challenge.
Another thing that made this difficult was the fact that it is located fairly low in the southern sky and is already at the meridian (the highest point it will reach in the night sky) when twilight ends. That gives me about an hour for exposure before it is cut off by the trees on the west side of my driveway.
The results after one night of capture were disappointing. Way too much noise and too little signal. Because it was low in the southern sky also means that I am looking obliquely through as much of the atmosphere that I can - which also hurts results. So I captured two nights of data (this is first for me) and then stacked the results to get this. I still had signal-to-noise issues, so I tried applying the Topaz Noise AI tool to it, using its special dark scene mode and it did an amazing job cleaning things up.
So - not the best image, but an interesting challenge.
More Information
Wikipedia Entry: Arp 271
This image was taken with the EFOSC instrument, attached to the 3.58-meter New Technology Telescope at ESO's La Silla Observatory in Chile.
Capture Details
Lights Frames
Taken on the nights of 6-11-20 and 6-15-20
54 x 120 seconds, bin 1x1 @ -15C, Gain UNity
Total of 1.8 hours
Cal Frames
35 Darks
45 flats,
45 bias frames
Capture Hardware
Scope: Astrophysics 130mm Starfire F/8.35 APO refractor
Guide Scope: Televue 76mm Doublet
Camera: ZWO AS2600mm-pro with ZWO 7x36 Filter wheel with ZWO LRGB filter set,
and Astronomiks 6nm Narrowband filter set
Guide Camera: ZWO ASI290Mini
Focus Motor: Pegasus Astro Focus Cube 2
Mount: Ioptron CEM60
Polar Alignment: Polemaster camera
Software
Capture Software: PHD2 Guider, Sequence Generator Pro controller
Image Processing: Deepsky Stacker, Pixinsight, Photoshop, Topz AI Denoise - assisted by Coffee, extensive processing indecision and second-guessing, editor regret, and much swearing…..
During August and September I was out shooting every clear night. I had learned a lot of things but I was also noticing several issues that were causing me problems as I did more imaging. I decided to do something to address those issues….