Supernova
Cygnus Loop (SNR G74.0-8.5)
Supernova remnant
The shock wave of a supernova expanding at thousands of kilometres per second: it sweeps up and heats the interstellar gas and shines in radio waves.
| Type | Supernova |
|---|---|
| Constellation | Cygnus |
| Distance | 735 pc (2.4 thousand ly) |
| Diameter | 133.7 ly |
| Type | Shell type |
| Radio flux (1 GHz) | 210 Jy |
| Source | Green's SNR Catalogue |
| Right ascension (J2000) | 20h 51m 00.0s |
| Declination (J2000) | +30° 40′ 00″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 59° S. North of latitude 59° N it never sets. It stands highest at midnight in August, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around 372 BC. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 43 million years.