Planetary nebula
K 3-21
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 | Aquila |
| Distance | 10,200 pc (33.3 thousand ly) · estimated |
| Diameter | 1.2 ly |
| Central star | V 16.9 |
| PN G name | PN G047.1+04.1 |
| Source | Strasbourg–ESO PN Catalogue |
| Right ascension (J2000) | 19h 02m 40.3s |
| Declination (J2000) | +14° 28′ 52″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 76° S. North of latitude 76° N 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 33 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 590 million years.