Planetary nebula
He 2-138
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 | Triangulum Australe |
| Distance | 5,000 pc (16.3 thousand ly) · estimated |
| Diameter | 0.6 ly |
| Central star | V 10.9 · O(H) |
| Expansion speed | 11 km/s |
| PN G name | PN G320.1-09.6 |
| Source | Strasbourg–ESO PN Catalogue |
| Right ascension (J2000) | 15h 56m 01.3s |
| Declination (J2000) | −66° 09′ 11″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 24° N. South of latitude 24° S it never sets. It stands highest at midnight in May, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 16 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 289 million years.