Planetary nebula
A 82
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 | Cassiopeia |
| Distance | 1,690 pc (5.5 thousand ly) · estimated |
| Diameter | 2.5 ly |
| Central star | V 14.9 |
| Expansion speed | 25 km/s |
| PN G name | PN G114.0-04.6 |
| Source | Strasbourg–ESO PN Catalogue |
| Right ascension (J2000) | 23h 45m 47.5s |
| Declination (J2000) | +57° 04′ 01″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 33° S. North of latitude 33° N it never sets. It stands highest at midnight in September, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 5,512 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 98 million years.