θ¹ Orionis C is the most massive star of the Trapezium, a hot blue giant whose ultraviolet light makes most of the Orion Nebula glow.
At a glance
| type | blue giant (class O) |
|---|---|
| distance from the Sun | 1,340 light-years (412 pc) |
| its light left it | 1,340 years ago |
| luminosity | 200,000 × the Sun |
| radius | 10.6 × the Sun |
| surface temperature | 39,000 K |
Read off the piece’s own catalogue, the same values it draws with.
About θ¹ Orionis C
At the heart of the Orion Nebula lies the Trapezium, a tight knot of young stars, and the brightest of them is θ¹ Orionis C. It is an O-type star, among the hottest and most massive known so close to the Sun, and it is itself a close binary.
Its ultraviolet radiation strips electrons from the hydrogen of the surrounding cloud, and the gas glows as the electrons are recaptured. Most of the nebula’s light can be traced to this one star. Its powerful wind has blown a cavity in the cloud facing us, which is why we can see into the nebula at all.
Hubble images show young stars nearby still wrapped in discs of gas and dust, the material of future planets, being eroded by its light.
What you see in the piece
Fly to the Orion Nebula and θ¹ Orionis C is the brightest of the four Trapezium stars, blue-white because it is extremely hot; the glowing gas around it is lit by its ultraviolet light.
Questions
What powers the Orion Nebula?
Mainly θ¹ Orionis C, the brightest star of the Trapezium, whose ultraviolet light makes the surrounding gas glow. It shines about 200,000 × the Sun.
How far away is the Trapezium?
The Trapezium stars are 1,340 light-years (412 pc) from the Sun, at the heart of the Orion Nebula.