Supernova
MSH 17-39 (SNR G357.7-0.1)
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. The distance is estimated from the radio surface-brightness–diameter (Σ–D) relation and may be off by a factor of two.
| Type | Supernova |
|---|---|
| Constellation | Scorpius |
| Distance | 4,630 pc (15.1 thousand ly) · estimated |
| Diameter | 21.5 ly |
| Radio flux (1 GHz) | 37 Jy |
| Source | Green's SNR Catalogue |
| Right ascension (J2000) | 17h 40m 29.0s |
| Declination (J2000) | −30° 58′ 00″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 59° N. South of latitude 59° S it never sets. It stands highest at midnight in June, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 15 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 268 million years.