Star clusters are just some of the non-galaxy objects to be found in the SDSS survey. Identifying them visually can be a problem as one cluster, especially a Globular Cluster, looks much like another! NED often helps but not always. Because most of them do not have their own ObjID one of many nearby ObjIDs has to be used for identification which is why searching the forum does not always produce a result. So to help out with the identification I have catalogued them in two lists. If you find one ? now you?ll know which one it is! This is the open clusters index. You'll find the globular clusters index
here.
Open clusters are physically related groups of stars held together by mutual gravitational attraction. They are all roughly the same distance from us in the same region of space and are thought to have originated from the same cosmic dust cloud. They reside in the spiral arms of the Milky Way and there are estimated to be between 50,000 to 100,000 of them. They are looser collections of stars than Globulars containing anything from 5 to 500 stars. Because of their apparent size many are best viewed through binoculars.
OPEN CLUSTERS
