Sh2-216
Planetary Nebula in Perseus
About
A very old planetary nebula in Perseus, about 420 light-years away and the closest one known. It is roughly 600,000 years old and about 100′ across, over three times the Moon's width. Its eastern edge is brighter where the gas meets the interstellar medium as the nebula moves.
Imaging tips
- At 240–400 mm on APS-C (370–620 mm full frame) it fits, and a relatively wide-field scope is what one write-up recommends.
- Narrowband is the way in: one imager shot Hα, OIII and SII, and even 17 hours with a 300 mm f/2.8 lens left it among the faintest targets he had shot.
- One imager logged 55 hours in 3 nm Hα, OIII and SII and still called it extremely faint; its Hα was much dimmer on one side, per another.
- Best in November and December; it peaks near 87° altitude from 50°N.
Facts
- Size
- 100′
- Magnitude
- —
- Coordinates
- RA 4h 43.4m, Dec +46° 42′
- Framing, APS-C
- 240–400 mm
- Framing, full frame
- 370–620 mm
- Best months
- Nov, Dec
- Peak altitude
- 87° from 50°N, 78° from 35°N