M20 and M21 – Trifid Nebula and Open Cluster

M20 – The Trifid Nebula found in the constellation Sagittarius is another H II region, but it’s a whole lot of things rolled into one nebula. Within the nebula is an open cluster of stars, the red portion of the nebula is the emission nebula, the reflection nebula is the blue portion, and there is even a dark nebula forming what looks like gaps in the red nebulosity. This nebula, like all other nebula, is a stellar nursery, and lies 8 light-years away from the bright star in the center of the nebula.

M20 and M21 Location

‘X’ Marks the spot of M20 and M21

The word Trifid means ‘divided into three lobes,’ the dark nebula running through the red emission nebula forms the three lobes.

The open cluster, M21 just north of the Trifid Nebula at low magnification should be in the same view (depending on your telescope or camera). M21 is a cluster of relatively young stars, astronomically speaking, at only 4.6 million years old. Not visible to the unaided eye, but easily visible with a small telescope or a pair of binoculars. This cluster is relatively dim, and lies roughly at a distance of 4.25 thousand light-years from Earth.

My Observation: This nebula is a little over 1° north of the Lagoon Nebula and the cluster of stars within the red emission part shine brightly. The only part of the nebula that is visible from my location is the emission nebula and the dark nebula cutting through it. It’s very faint and you need to use your averted vision to see any detail. Laying low on the horizon also makes this a difficult object to get much detail from, but is a wonderful treat to the eyes when you see it.

M20 and M21 - Trifid Nebula and Open Cluster. 6-14-12

M20 and M21 – Trifid Nebula and Open Cluster. 6-14-12

M20 & M21 – The Trifid Nebula and Open Cluster. This is a re-edit of the same data previously collected.

This is a composite of 38 images at 30 seconds a piece stacked with 41 dark frames. Stacked in Deep Sky Stacker and post processing done in Photoshop.

3 thoughts on “M20 and M21 – Trifid Nebula and Open Cluster

  1. Pingback: Visiting Some Old Objects | Adirondack Astronomy

  2. Wow, the star cluster in M21, as if some body wrote with stars the Sanskrit symbol OM,……….generally used to address, the Creater in Vedas ,……who knows may be the ancients saw it there first. ,!!

    • Thanks you. It does sort of resemble that symbol. Thanks for stopping by, and hope you check back for more in the future.

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