Planetary nebula
K 3-90
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 | 5,760 pc (18.8 thousand ly) · estimated |
| Diameter | 0.8 ly |
| Expansion speed | 15 km/s |
| PN G name | PN G126.3+02.9 |
| Source | Strasbourg–ESO PN Catalogue |
| Right ascension (J2000) | 1h 24m 58.9s |
| Declination (J2000) | +65° 38′ 37″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 24° S. North of latitude 24° 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 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 333 million years.