Waid Observatory

Object: NGC 4490/85 - ARP 269

Date: May 21-22-23, 2023   -    Location: Davis Mountains west of Fort Davis, TX
Telescope: 10 inch RC    -    Mount: Paramount MX   -  Camera: Apogee Alta F8300M
Exposure: Lum. = 34 x 5 min., Bin 1x1 - Red, Green, Blue, Ha = 24x5 min. each, Bin 2x2

Click on the image to view at higher resolution.


NGC 4490/85 - ARP 269

NGC 4490, commonly known as the Cocoon Galaxy[1], lies in the constellation Canes Venatici at a distance of approximatel 25 million light years[1].  It is interacting gravitationally with a smaller companion galaxy cataloged NGC 4485[1].  This pair is included in the ARP catalog of peculiar galaxies as ARP 269[1,2].  These galaxies are known for being one of the closest interacting galactic systems[2] to the Milky Way.  The interaction with NGC 4485 has produced a high star formation rate in NGC 4490[1,2].  The Spitzer Space Telescope has detected a double neucleus in NGC 4490[2].  One neucleus is visible in the optical and one only visible at infrared and radio wavelengths[2].  Both galaxies are connected with a stream of material about 25,000 light years in length[3}.  NGC 4485 has already made its closest approach and is now moveing away from NGC 4490[3].

1Wikipedia: https://en.wikipedia.org/wiki/NGC_4490
2A. Lawrence, et al.: https://arxiv.org/pdf/2001.05601.pdf
3ESA/Hubble: https://esahubble.org/images/heic1910b/

Copyright Donald P. Waid