Celestial hemisphere:  Northern  ·  Constellation: Canes Venatici (CVn)  ·  Contains:  NGC 4485  ·  NGC 4490
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NGC 4490 Cocoon Galaxy #1, Molly Wakeling
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NGC 4490 Cocoon Galaxy #1

Getting plate-solving status, please wait...
NGC 4490 Cocoon Galaxy #1, Molly Wakeling
Powered byPixInsight

NGC 4490 Cocoon Galaxy #1

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Description

The Cocoon Galaxy!

Come to find out, imaging from a rather light-polluted area is hard. Who knew! I keep thinking that my image processing skills are decreasing, but then I have to remember that my data are not that great!

This image is my current title-holder for my Longest Exposure, at a total of 24.5 hours! I took it over the course of two months in February and March. Exciting!

The Cocoon Galaxy, or NGC 4490 by its New General Catalog number, is a barred spiral galaxy 25 million lightyears behind the galaxy-rich constellation Canes Venatici. During the spring, the night-side of the Earth is facing out and away from the main disk of the galaxy, allowing us to see a vast abundance of other galaxies. The little teardrop coming off its left side in this frame is NGC 4485, which is interacting with 4490, causing a rapid burst of star formation -- hence all of the pockets of red-glowing hydrogen gas.

A paper just published in February issue of the Astrophysical Journal reveals that the Cocoon Galaxy actually has a rare double-core structure. One core is visible in optical light, but the other is obscured by so much dust and gas that it's only visible at radio and infrared wavelengths. It is likely a result of a relatively recent galaxy merger, although a double-nucleus is very rare for galaxies on the smaller side, like this one.

Details:

Ha & L with ZWO ASI1600MM Pro

RGB with ZWO ASI294MC Pro

Subframes: Ha: 20x300s, 22x600s (Total: 5h20m)

RGB: 52x600s (Total: 8h40m)

L: 29x300s, 48x600s (Total: 10h25m)

Total: 24h25m

Gain/ISO: Ha, L: 139

RGB: 120

Acquisition method: Sequence Generator Pro

Stacking program: PixInsight 1.8.8-5

Post-Processing program: PixInsight 1.8.8-5

Darks: L/Ha, -20C, 300s: 117

L/Ha, -20C, 600s: 87

Ha, -25C, 300s: 20

RGB: 79

Biases: 0

Flats: 50 each

Temperature: -20C

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NGC 4490 Cocoon Galaxy #1, Molly Wakeling