C12 — Fireworks Galaxy
Galaxy in Cygnus
About
NGC 6946, a spiral galaxy seen face-on on the Cygnus–Cepheus border, roughly 22–25 million light-years away. Around ten supernovae have been seen in it since 1917, far above the Milky Way's rate, which earned it the Fireworks nickname.
Imaging tips
- About 12′ across, so it needs 2,020–3,370 mm on APS-C to span a third to half of the frame; a shorter lens leaves it as a small island in a wide star field.
- Faint at 22.9 mag/arcsec² and dimmed further by dust in our own Milky Way, so plan many hours of broadband data; one imager spent about 10 hours in RGB, luminance and Hα.
- Hα blended into the colour image brings out the red star-forming regions among the blue arms.
- The open cluster NGC 6939 lies not far away, and imagers have combined the two in one wide-field composite.
- Best in July and August; it peaks near 80° altitude from 50°N.
Facts
- Size
- 12′ × 11′
- Magnitude
- 9.0
- Coordinates
- RA 20h 34.9m, Dec +60° 9′
- Framing, APS-C
- 2020–3370 mm
- Framing, full frame
- 3090–5160 mm
- Best months
- Jul, Aug
- Peak altitude
- 80° from 50°N, 65° from 35°N