Planetary nebula
NGC 6818
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.
| Type | Planetary nebula |
|---|---|
| Constellation | Sagittarius |
| Distance | 2,200 pc (7.2 thousand ly) |
| Diameter | 0.7 ly |
| Central star | WNb ? |
| Expansion speed | 28 km/s |
| PN G name | PN G025.8-17.9 |
| Source | Strasbourg–ESO PN Catalogue |
| Right ascension (J2000) | 19h 43m 58.0s |
| Declination (J2000) | −14° 09′ 07″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 76° N. South of latitude 76° S it never sets. It stands highest at midnight in July, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 7,176 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 127 million years.