These bodies are classified under a scheme developed by Robert Trumpler.
One commonly used method for determining the age of these bodies relies on measuring the abundance of lithium and beryllium within them. By comparing photographic plates of one of these bodies taken at different times, Adriaan van Maanen was able to measure proper motion within that body. These bodies are classified under a scheme developed by Robert Trumpler. One alternate name for these bodies is due to the fact that they are often located in or near (*) galactic planes. These bodies are not found in elliptical galaxies, since there is very little star formation there. Examples of these objects include the Praesepe, the Hyades, and the Pleiades. For 10 points, name these low-density groups of relatively young stars.
One commonly used method for determining the age of these bodies relies on measuring the abundance of lithium and beryllium within them.
open clusters [or galactic clusters; prompt on star clusters; prompt on clusters]