star clusters. pre clusters courtesy university of oregon
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Star ClustersStar Clusters
Pre clustersPre clusters
Courtesy University of Oregon
TypesTypes
AssociationsAssociations Ironically, a Ironically, a disdisassociating associating
open clusteropen cluster Big Dipper/Ursa MajorBig Dipper/Ursa Major
Open ClustersOpen Clusters ~1000 stars~1000 stars Found in the spiral arms of the Found in the spiral arms of the
galaxygalaxy Mostly young hot starsMostly young hot stars
Pop IPop I
Globular ClustersGlobular Clusters ~1 million stars~1 million stars Found in the galactic haloFound in the galactic halo Mostly old starsMostly old stars
Pop IIPop II
Double ClusterDouble Cluster
What stellar ages tell us:What stellar ages tell us:The Turnoff PointThe Turnoff Point
We can know We can know something about the something about the age of a cluster of age of a cluster of stars by looking at stars by looking at when the most when the most massive stars turnoff massive stars turnoff the MSthe MS
Two animations followTwo animations follow
9.210 )(10 sunM
Mt
Newly found clusters in NGC 6397 Newly found clusters in NGC 6397 (left) 1BLY; M15 (right)(left) 1BLY; M15 (right)
Beehive Open ClusterBeehive Open Cluster
M80, one of the densest of the 147 known globular M80, one of the densest of the 147 known globular star clusters in the Milky Way; 28,000 LYstar clusters in the Milky Way; 28,000 LY
IR image of the Arches ClusterIR image of the Arches Cluster
About 33 pc from the About 33 pc from the galactic nucleusgalactic nucleus
100 O class stars100 O class stars Globular or Open??Globular or Open??
Most densely packed Most densely packed cluster observedcluster observed
Separation ~ light Separation ~ light weeks weeks apartapart
Not these arches ->