| Object type: | Emission (H II region) nebula |
|---|---|
| Distance from Earth: | 3,200 light years 1,000 parsecs |
| Distance across Nebula: | 12 light years 3.7 parsecs |
The Trifid Nebula is a cloud of interstellar gas illuminated by a relatively new star (age 7 million years). Three dark radial dust lanes divide the cloud, hence its name. The light being emitted from the hydrogen gas is predominantly the red H-alpha spectral line, making the nebula appear pink.
Pictured with the Trifid is a blue nebula surrounding star HD 164514. This star is not hot enough to excite the hydrogen gas like the star within the Trifid, so all we see is starlight reflected from dust particles and cold gas. These particles selectively scatter blue light, just as sunlight scattered in Earth's sky is blue.
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