C33 — Eastern Veil Nebula
Supernova Remnant in Cygnus
About
The eastern arc of a supernova remnant in Cygnus, brightest at NGC 6992 and fading south through NGC 6995. A star about 20 times the Sun's mass exploded roughly 10,000 to 20,000 years ago, about 2,400 light-years away; Hubble has since watched the shell grow.
Imaging tips
- The brightest stretch, NGC 6992, runs into NGC 6995, so the two can fill one frame as a pair of filaments.
- The whole Cygnus Loop spans about 3°, so a frame of roughly 132′ across at 400–670 mm on APS-C shows only part of it; wide refractors suit it.
- Narrowband Hα and OIII is the usual route: one gallery shows 1 hour of each per panel, and another image used over 4 hours in a bicolour palette.
- Single 5-minute subs show little before heavy processing, so a cooled camera and many subs help.
- Best around July and August, peaking near 72° from 50°N.
Facts
- Size
- 60′ × 8′
- Magnitude
- —
- Coordinates
- RA 20h 56.8m, Dec +31° 43′
- Framing, APS-C
- 400–670 mm
- Framing, full frame
- 620–1030 mm
- Best months
- Jul, Aug
- Peak altitude
- 72° from 50°N, 87° from 35°N