M8, the Lagoon Nebula, M20, the Trifid Nebula
and the open cluster, M21
and the open cluster, M21
Messier 8, the Lagoon Nebula, is one of the brightest star forming areas of the sky. It is the red
emission nebula on the left side of this image. M8 is a rather large nebula being about 3 x 1 times
the size of the full moon as seen from Earth. The nebula contains a number of Bok globules - dark,
collapsing clouds of protostellar material. Several can be seen in this image. These globules are
thought to be active star forming areas. The distance from Earth of M8 is a bit uncertain with
estimates being from about 4000 to 6000 light years. M8 is situated in a very conspicuous star field
of the constellation Sagittarius, which is located in the direction of the center of the Milky Way. Also
in this area, and shown in this image, are the nebula M20 and the open cluster M21.
M20, the Trifid Nebula is the nebula on the right in this image. It is both a reflection nubula (blue)
and emission nebula (red). This nebula is famous for its three-lobed appearance which is actually
due to a dark nebula, Bernard 85, which outlines the three lobes. The distance of M20 from Earth is
also uncertain. Estimates range from 2000 to 9000 light years.
M21 is a relatively young cluster of tightly packed stars is seen on the right edge of the image. It is
located about 2000 to 4000 light years from Earth. A few blue giant stars have been identified in the
cluster, but Messier 21 is composed mainly of small dim stars. With a magnitude of 6.5, M21 is not
visible to the naked eye; however, with the smallest binoculars it can be easily spotted on a dark
night.
This image was taken with a modified Canon XSi and a Takahashi 106ED refractor telescope. A total
of 22 x 4 minute exposures were combined to create the image.
emission nebula on the left side of this image. M8 is a rather large nebula being about 3 x 1 times
the size of the full moon as seen from Earth. The nebula contains a number of Bok globules - dark,
collapsing clouds of protostellar material. Several can be seen in this image. These globules are
thought to be active star forming areas. The distance from Earth of M8 is a bit uncertain with
estimates being from about 4000 to 6000 light years. M8 is situated in a very conspicuous star field
of the constellation Sagittarius, which is located in the direction of the center of the Milky Way. Also
in this area, and shown in this image, are the nebula M20 and the open cluster M21.
M20, the Trifid Nebula is the nebula on the right in this image. It is both a reflection nubula (blue)
and emission nebula (red). This nebula is famous for its three-lobed appearance which is actually
due to a dark nebula, Bernard 85, which outlines the three lobes. The distance of M20 from Earth is
also uncertain. Estimates range from 2000 to 9000 light years.
M21 is a relatively young cluster of tightly packed stars is seen on the right edge of the image. It is
located about 2000 to 4000 light years from Earth. A few blue giant stars have been identified in the
cluster, but Messier 21 is composed mainly of small dim stars. With a magnitude of 6.5, M21 is not
visible to the naked eye; however, with the smallest binoculars it can be easily spotted on a dark
night.
This image was taken with a modified Canon XSi and a Takahashi 106ED refractor telescope. A total
of 22 x 4 minute exposures were combined to create the image.
| M8, the Lagoon Nebula (left), M20, the Trifid Nebula (lower right) and the open cluster M21 (center, far right); click on the image for larger version and then click again for full-size |
Below is a wide field image of the area around M8/M20/M21. It was taken with a modified Canon
XSi equipped with a Canon 85mm lens at about f/3. The total exposure was 45 minutes (3 min x
15). The mount was an Astrotrac. Click the images for full size. In addition to the objects
labeled, there are a lot of globular clusters in this area, but at this scale they are hard to identify.
Thanks to my friend Fred Pilcher for helping with the identifications.
XSi equipped with a Canon 85mm lens at about f/3. The total exposure was 45 minutes (3 min x
15). The mount was an Astrotrac. Click the images for full size. In addition to the objects
labeled, there are a lot of globular clusters in this area, but at this scale they are hard to identify.
Thanks to my friend Fred Pilcher for helping with the identifications.
