H-NGC4490 — Cocoon Galaxy
Galaxy in Canes Venatici
About
The Cocoon Galaxy, a barred spiral in Canes Venatici about 25 million light-years away, locked in an encounter with the small NGC 4485 (together Arp 269). It has a double nucleus and a stellar stream about 25,000 light-years long joining the pair. It is in the Herschel 400.
Imaging tips
- Only about 6×3′, so it is too small to frame: use a long focal length and a fine pixel scale.
- Its partner NGC 4485 is magnitude 11.9, and the two are catalogued together as Arp 269.
- One imager collected 6.7 hours with a 152 mm refractor: 45 × 300 s luminance, then 13, 12 and 11 × 300 s in red, green and blue.
- Another imager shot only luminance, 13 × 10 minutes (2 hours), from a Bortle 9 sky with a 1085 mm focal length.
- Best around March and April; it peaks near 82° altitude from 50°N.
Facts
- Size
- 6′ × 3′
- Magnitude
- 9.8
- Coordinates
- RA 12h 30.6m, Dec +41° 38′
- Framing, APS-C
- longer than 4000 mm
- Framing, full frame
- longer than 4000 mm
- Best months
- Mar, Apr
- Peak altitude
- 82° from 50°N, 83° from 35°N