Huser Astro Gallery - Star Clusters

Click on photos to enlarge. 

M13, NGC6205, or the “Great Globular Star Cluster” in Her, is the finest cluster. Thousands points of lights can be seen if a scope larger than 10” is used, but only a faint and hazy speck of light with the unaided eye on a very dark night. More than 25,000 stars brighter than mag 20 have been counted in M13. Its distance is 25,000 l-y. The impression that the stars are “packed” in the cluster’s center is false. The density is still not more than 1 star per cubic l-y, which is rather dense but not ‘packed’. Still if Earth would be in the center, we would see thousands of stars brighter than Venus, a few even as bright as the Moon! Since no dark nights there, astronomy would not be possible. M13 is one of the older “globs”, about 10 billion years.

 M14, NGC6218 in Oph, is another old cluster of stars. Its only notoriety is that it had a rare SuperNova in 1938, which was not detected until 1967 when old photographic plates were re-examined. Only two SuperNovae in ‘globs’ are on record.

M22, NGC6656, in Sgr, is one of the six finest globular clusters and also very near us at 10,000 l-y.

 M24, NGC6603, also in Sgr, is the bright one between the Lagoon and Swan nebulae in a bright portion of the Milky Way. It is rectangular and subtends 1 x 2 degrees; hence only a small portion is in the picture, 1/3 x ½ degree. This one will be revisited soon for a longer exposure.

 M47, NGC2422 in Pup, is a bright but sparse group, only 2,000 l-y from Earth. The bright star just right of center is the brilliant double, Sigma-1121; stars of mag 7 and 7.5 only 7” apart, which by the way is a separation of 4,000 AU (100 radii of Pluto’s orbit). The double is not resolved in the picture, too bright. 2/3rd on the line from this double to the top RH corner is a 7.8 mag K-type giant, a really orange one. We like to take color exposures of this one soon

IC4715 in Sgr is located in the NE corner of the large M24 and shows some nebulosity

IC1283 in Sgr is located ½ degree SE of M24 and shows clearly some interesting nebulosities

 NGC6559 in Sgr and located 10’ E of M8, the Lagoon Neb. It has a nice nebulosity in IR with a string of stars. A color image of 6559 is on my agenda!