θ¹ Orionis D is one of the four Trapezium stars at the centre of the Orion Nebula, a hot young star that helps light the surrounding gas.
At a glance
| type | blue star (class O) |
|---|---|
| distance from the Sun | 1,340 light-years (412 pc) |
| its light left it | 1,340 years ago |
| luminosity | 30,000 × the Sun |
| radius | 6 × the Sun |
| surface temperature | 32,000 K |
Read off the piece’s own catalogue, the same values it draws with.
About θ¹ Orionis D
θ¹ Orionis D is the easternmost of the four bright Trapezium stars, a hot, massive young star second in that group to θ¹ Orionis C. Its ultraviolet light adds to the glow of the nebula around it.
Massive stars like D live only briefly by the standard of the Sun. Those in the Trapezium are among the youngest massive stars close enough to examine in detail, and they show what the hot, blue stars of older clusters looked like when newly formed.
The nebula itself is the near side of a much larger molecular cloud, still forming stars behind the bright gas.
What you see in the piece
Fly to the Orion Nebula and θ¹ Orionis D is one of the four blue-white Trapezium stars; together they form the small figure that gives the group its name.
Questions
Why is it called the Trapezium?
Its four brightest stars, θ¹ Orionis A to D, form a small four-sided figure in a telescope.
How hot is θ¹ Orionis D?
Its surface is about 32,000 K, and it shines about 30,000 × the Sun.