NGC 4490 and smaller neighbouring NGC 4485 are interacting galaxies, around 25 million lightyears distant. NGC 4490 is a barred spiral around 50,000 lightyears across, while the smaller galaxy is irregular and 20,000 lightyears in diameter.
It is thought that they collided around 400 million years ago, leading to increased star formation, with many of the new stars in the tidal tail connecting them – just visible in this image. There is a large halo of atomic hydrogen surrounding them, around nine times larger than the space occupied by the galaxies themselves.
This image is the result of 5h of data capture, over 3 evenings in April 2021.
ZWO ASI071MC Pro colour camera, through a Teleskop-Service 8-inch Ritchey-Chretien reflector, using an Astronomik UV/IR filter.
Date: 16/04/2021
Location: Horsham, West Sussex
Photographer: Graham Wilcock
