The constellation Sagittarius is at the heart of our Milky Way Galaxy and is full of wonderful deep space gems. At the top of the list is the great Lagoon Nebula due to its brightness and size. Right above it is another wonderful target: the Trifid Nebula, a very unusual target.
The Trifid Nebula, or M20, is not as bright or large as the Lagoon Nebula. Binoculars or a telescope will likely be needed to spot it. But what it lacks in brightness, it makes for with an unusual, remarkable structure. Its name comes from the fact that it consists of three types of nebulas:
* Reflection nebula -- above, blue, reflects the light of hot blue stars within.
* Emission nebula -- below, red, glows due to the high energy given off by stars within.
* Dark nebula -- stretches across the emission nebula, dark since it is thick and blocks light.
From a dark site on a moonless night, look first for the brightest stars and then try to spot the nebulosity. To really 'see' the colors requires astrophotography since our eyes are not good at seeing colors when the light is dim.
Viewing Trifid Nebula/M20
Level
Moderate
Rating
Best Viewing
June to October
Find
Start by finding the teapot asterism in the constellation of Sagittarius. Then use the two stars that form the spout including bright Kaus Media to form a triangle with the Lagoon Nebula as the third point. Then look up (north) 1 degree (a finger-width). We recommend you use binoculars first.
Binoculars will reveal bright stars and possibly some nebulosity.
For the best views, use a telescope. Begin with low power to center it. Then switch to higher power to see the bright stars and possible nebulosity. The larger the telescope, the better. Take time to enjoy the view! Try drawing it.
