M76 — Little Dumbbell
Planetary Nebula in Perseus
About
The Little Dumbbell, a bipolar planetary nebula in Perseus about 2,500 light-years away. Observers once thought it was two nebulae, hence its NGC 650 and NGC 651 numbers. We look at a ring of gas edge-on, which makes the central bar, and gas lobes extend from both ends.
Imaging tips
- Only about 3′ by 2′, so it is too small to frame: use a long focal length and a fine pixel scale. One imager calls its small size the main difficulty.
- Narrowband suits a planetary nebula: one 12-inch f/5 mono session logged 4 hours of Hα and 2.3 hours of OIII in 20-minute subs, plus a short SII set.
- A DSLR can reach it too: one pair of modified DSLRs at f/8 and 1,040 mm gave 80 minutes of 10-minute subs, one camera unfiltered for OIII and one behind a CLS filter.
- Best from September to November, and it passes nearly overhead from 50°N.
Facts
- Size
- 3′ × 2′
- Magnitude
- 10.1
- Coordinates
- RA 1h 42.3m, Dec +51° 35′
- Framing, APS-C
- longer than 4000 mm
- Framing, full frame
- longer than 4000 mm
- Best months
- Sep, Oct, Nov
- Peak altitude
- 88° from 50°N, 73° from 35°N