Planetary nebula
A 39
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 | Hercules |
| Distance | 1,350 pc (4.4 thousand ly) · estimated |
| Diameter | 3.7 ly |
| Central star | V 15.7 · sd O |
| Expansion speed | 32 km/s |
| PN G name | PN G047.0+42.4 |
| Source | Strasbourg–ESO PN Catalogue |
| Right ascension (J2000) | 16h 27m 33.4s |
| Declination (J2000) | +27° 54′ 35″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 62° S. North of latitude 62° N 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 4,403 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 78 million years.