Planetary nebula
H 2-18
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 | Sagittarius |
| Distance | 5,820 pc (19.0 thousand ly) · estimated |
| Diameter | 0.3 ly |
| PN G name | PN G006.3+04.4 |
| Source | Strasbourg–ESO PN Catalogue |
| Right ascension (J2000) | 17h 43m 28.8s |
| Declination (J2000) | −21° 09′ 53″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 69° N. South of latitude 69° S it never sets. It stands highest at midnight in June, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 19 thousand years ago. At that time Homo sapiens was spreading out of Africa; there was no farming yet. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 337 million years.