Nebula
RCW 99
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 | Norma |
| Distance | 3,000 pc (9.8 thousand ly) · estimated |
| Diameter | 9.5 ly |
| WISE name | G328.572-00.527 |
| Catalogue status | Known H II region |
| Source | WISE H II Catalog v3.0 |
| Right ascension (J2000) | 15h 59m 36.6s |
| Declination (J2000) | −53° 45′ 21″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 36° N. South of latitude 36° S it never sets. It stands highest at midnight in May, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 9,785 years ago. At that time the first farming villages were being founded; there was no writing yet. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 174 million years.