Planetary nebula
K 3-91
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 | Cassiopeia |
| Distance | 8,440 pc (27.5 thousand ly) · estimated |
| Diameter | 1.3 ly |
| Central star | V 20.5 |
| PN G name | PN G129.5+04.5 |
| Source | Strasbourg–ESO PN Catalogue |
| Right ascension (J2000) | 1h 58m 35.9s |
| Declination (J2000) | +66° 34′ 04″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 23° S. North of latitude 23° N it never sets. It stands highest at midnight in October, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 28 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 488 million years.