Planetary nebula
Sa 2- 21
Planetary nebula
A shell of gas thrown off by a dying Sun-like star, glowing in the ultraviolet light of the hot core at its centre. Within a few tens of thousands of years it will disperse and fade from view. The distance is a statistical estimate, uncertain by 30–50 %.
| Type | Planetary nebula |
|---|---|
| Constellation | Puppis |
| Distance | 3,340 pc (10.9 thousand ly) · estimated |
| Diameter | 2.1 ly |
| PN G name | PN G238.9+07.3 |
| Source | Strasbourg–ESO PN Catalogue |
| Right ascension (J2000) | 8h 08m 44.0s |
| Declination (J2000) | −19° 13′ 50″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 71° N. South of latitude 71° S it never sets. It stands highest at midnight in January, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 11 thousand years ago. At that time the first farming villages were being founded; there was no writing yet. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 193 million years.