Last week we covered multiple star systems, but what if we added thousands or even millions of stars to the mix? A star cluster. There are different kinds of clusters, though. Open clusters contain hundreds or thousands of stars held together by gravity. They’re young and evaporate over time, their stars let loose to roam space freely. Globular clusters, on the other hand, are larger, have hundreds of thousands of stars, and are more spherical. They’re very old, a significant fraction of the age of the Universe itself, and that means their stars have less heavy elements in them, are redder, and probably don’t have planets (though we’re not really sure).
Check out the Crash Course Astronomy solar system poster here: [ Ссылка ]
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Chapters:
Introduction: Star Clusters 00:00
Determining the Age of Star Clusters 2:04
Open Clusters Evaporate 3:23
The Pleiades Star Cluster 4:27
Globular Clusters 5:50
Review 9:25
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PHOTOS/VIDEOS
Magellanic gemstone in the southern sky [NGC 290] [ Ссылка ] [credit: European Space Agency & NASA]
Extreme star cluster bursts into life in new Hubble image [ Ссылка ] [credit: NASA, ESA and the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration]
View of a Sun-like star within an open cluster (artist’s impression) [ Ссылка ] [credit: NASA, ESA, and M. Kornmesser]
Motion of stars in Omega Centauri [ Ссылка ] [credit: NASA, ESA, J. Anderson and R. van der Marel (STScI)]
47 Tucanae: Probing Extreme Matter Through Observations of Neutron Stars [ Ссылка ] [credit: NASA/CXC/Michigan State/A.Steiner et al]
Hubble Refines Distance to Pleiades Star Cluster [ Ссылка ] [credit: NASA, ESA and AURA/Caltech]
M45 Pleiades [ Ссылка ] [credit: T.A. Rector (University of Alaska Anchorage), Richard Cool (University of Arizona) and WIYN]
From the Pleiades to the Hyades [ Ссылка ] [credit: Rogelio Bernal Andreo]
Messier 035 Atlas Image [ Ссылка ] [credit: Two Micron All Sky Survey (2MASS), a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation]
Globular cluster 47 Tucanae [ Ссылка ] [credit: NASA, ESA, and the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration]
The oldest cluster in its cloud [ Ссылка ] [credit: ESA/Hubble & NASA]
An unexpected population of young-looking stars [ Ссылка ] [credit: ESA/Hubble & NASA]
View of a globular cluster (artist’s impression) [ Ссылка ] [credit: NASA, ESA, and M. Kornmesser]
All that glitters [ Ссылка ] [credit: ESA/Hubble & NASA]
Ещё видео!