open cluster | has age varies widely | ![has source: Ferris, T. 1988 Coming of Age in the Milky Way, Morrow, 2001-09-27 09:30:55.0 has source: Ferris, T. 1988 Coming of Age in the Milky Way, Morrow, 2001-09-27 09:30:55.0](facet.gif) |
is a part of disk | ![has source: Ferris, T. 1988 Coming of Age in the Milky Way, Morrow, 2001-09-27 09:30:55.0 has source: Ferris, T. 1988 Coming of Age in the Milky Way, Morrow, 2001-09-27 09:30:55.0](facet.gif) |
has catalog open cluster catalog | ![2001-09-27 09:30:55.0 2001-09-27 09:30:55.0](facet.gif) |
has definition A small, loose cluster of stars that typically contains several hundred members. The best examples are the Hyades and the Pleiades, both in the constellation Taurus. Open clusters line the Galactic plane, in contrast with globular clusters, which are members of the Galaxy's halo or thick disk. | ![has source: Croswell, K. 1995 The Alchemy of the Heavens, Anchor Books, 2001-09-27 09:30:55.0 has source: Croswell, K. 1995 The Alchemy of the Heavens, Anchor Books, 2001-09-27 09:30:55.0](facet.gif) |
has definition A comparatively loose grouping (mass range 102-103 M)sun of Population I stars, strongly concentrated in the spiral arms or the disk of the Galaxy (in fact, open clusters give a good indication of where the spiral arms are). Unlike associations, open clusters are dynamically stable. Depending on their age, stars in open clusters "peel off" from the main sequence at different points (the higher the turnoff point, the younger the cluster). (Sometimes called Galactic cluster; NGC 188 is the oldest known open cluster.) | ![has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:30:55.0 has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:30:55.0](facet.gif) |
is a kind of star cluster | ![2001-09-27 09:30:55.0 2001-09-27 09:30:55.0](facet.gif) |
collection of stars | has number of stars | ![2001-09-27 09:30:53.0 2001-09-27 09:30:53.0](facet.gif) |
celestial body | has spectra | ![2001-09-27 09:30:09.0 2001-09-27 09:30:09.0](facet.gif) |
physical object | has location or center of gravity | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has angular momentum | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has mass | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has velocity | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has momentum | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has temperature | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has volume | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has extent | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has material | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |