NGC 4490, also known as the Cocoon Galaxy, is a barred spiral galaxy in the constellation Canes Venatici. It is approximately 25 million light years from Earth. It interacts with its smaller companion NGC 4485 and as a result is a starburst galaxy. NGC 4490 and NGC 4485 are collectively known in the Atlas of Peculiar Galaxies as Arp 269.
It was discovered by William Herschel in 1788.

TARGET
Nomenclature: Arp 269, The Cocoon Galaxy, NGC 4490, NGC 4485
Right Ascension: 12:30:35.0
Declination: +41:39:06.00
Discovery: William Herschel in 1788

EQUIPMENT USED
APM TMB LZOS 152 refractor
10Micron GM2000 HPS mount
QSI6120 CCD camera
Astrodon filters

IMAGE CAPTURE
Luminance: 45x300 bin 1x1
Red: 13x300 bin 1x1
Green: 12x300 bin 1x1
Blue: 11x300 bin 1x1
Total integration: 6.7 hours
Pixel scale: 0.558 arcsec/pixel
Field radius: 0.181 degrees
Capture dates: 17-19 May 2021
Capture location:  Fregenal de la Sierra, Spain

IMAGE PROCESSING
Pre-processing: CCDStack2
Post-processing: Photoshop CS2