Star Clusters
| Comet 17/P Holmes |
| M 39, Open Cluster in Cygnus |
| M103, Open Cluster in Cassiopeia |
| M34, Open Cluster in Perseus |
| The Double Cluster (NGC 884 and NGC 869) |
Comets
Star clusters come in two general types: open clusters and globular clusters. The open variety is quite
common and consists of groups of stars traveling through space in a similar direction and speed. The
members are thought to have formed at a similar time in the distant past. Typically, an open cluster will be
made up of a 100 or so members. Many were catalogued in the 17th and 18th century as early
astronomers looked at areas of the night sky that looked "fuzzy" with the naked eye. These make nice
binocular targets.
Although the open clusters appear to be a scattering of stars that is more dense than the background,
globular clusters look like a compact ball of stars. In some cases the globular is made up of millions of
stars. Can you imagine the night sky if our sun was part of a globular? The origin of globular clusters is
still uncertain, but they tend to orbit our galaxy (the Milky Way) and are thought to be some of the oldest
groups of stars known. It is estimated that our galaxy has about 150 globular clusters.
Click on the image of interest to see a larger version.
common and consists of groups of stars traveling through space in a similar direction and speed. The
members are thought to have formed at a similar time in the distant past. Typically, an open cluster will be
made up of a 100 or so members. Many were catalogued in the 17th and 18th century as early
astronomers looked at areas of the night sky that looked "fuzzy" with the naked eye. These make nice
binocular targets.
Although the open clusters appear to be a scattering of stars that is more dense than the background,
globular clusters look like a compact ball of stars. In some cases the globular is made up of millions of
stars. Can you imagine the night sky if our sun was part of a globular? The origin of globular clusters is
still uncertain, but they tend to orbit our galaxy (the Milky Way) and are thought to be some of the oldest
groups of stars known. It is estimated that our galaxy has about 150 globular clusters.
Click on the image of interest to see a larger version.
| Omega Centauri |