xuše-ye setâre-yi (#)
Fr.: amas stellaire
1) A group of stars held together by the mutual
→ gravitational attraction of its members,
which are physically related through common origin. They are of two types:
→ open clusters and
→ globular clusters.
super star cluster (SSC)
Fr.: super amas stellaire
A group of hundreds to thousands of very young stars packed into an unbelievably small volume of a few parsecs in size. These objects represent the youngest stage of → massive star cluster evolution yet observed. The most massive and dense SSCs, with ages less than 106 years, may be proto globular clusters. SSCs are thought to dissolve within 10 million years and merge into the field star population.
tight star cluster
xuše-ye setâreyi-ye tang
Fr.: amas stellaire serré
A cluster of stars in which members are closely situated so that high resolution observations are required to distinguish them individually.
Ursa Major star cluster
xuše-ye Xers-e Bozorg (#)
Fr.: amas de la Grande Ourse
A moving star cluster containing over 100 stars that are scattered over an area of sky more than 1,000 minutes of arc in diameter. The five brightest stars of the → Big Dipper as well as → Sirius belong to this → dynamical stream.