Nebula
W 31
H II region
A cloud of ionised hydrogen (H II region): a stellar nursery glowing in the ultraviolet light of the young, hot O and B stars inside it. The distance follows from the gas’s radial velocity and the Galaxy’s rotation curve (kinematic method).
| Type | Nebula |
|---|---|
| Constellation | Sagittarius |
| Distance | 14,200 pc (46.3 thousand ly) · estimated |
| Diameter | 94.6 ly |
| WISE name | G010.160-00.350 |
| Catalogue status | Known H II region |
| Source | WISE H II Catalog v3.0 |
| Right ascension (J2000) | 18h 09m 23.9s |
| Declination (J2000) | −20° 19′ 12″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 70° N. South of latitude 70° 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 46 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 822 million years.