Chapter 13 Star Clusters Stars almost always form
- Slides: 15
Chapter 13: Star Clusters Stars (almost) always form in clusters globular cluster Open cluster • • The stars all formed at the same time They are all at the same distance They formed from the same material Only difference is their masses!
h & Chi Persei – Double Cluster in Perseus
Messier 35 and NGC 2158 – “open clusters” of different ages
Pleiades Open clusters: 1. Contain < ~ 1000 stars 2. Loosely gravitationally bound together 3. Younger than globular (some still contain O and B stars) 4. More enriched in heavy elements (“Population I” stars)
Messier 50 – An “open cluster” of stars
Open clusters that have become gravitationally unbound are stellar associations. If they continue to have similar proper motion, this is a moving group. Ursa Major moving group
globular clusters: 1. Contains ~1000 -106 stars 2. Extremely old: billions of years 3. Population II (low in heavy elements)
Globular cluster M 2 “He who cannot see gravity at work here has no soul. ” - Richard Feynman
HD Diagram for star clusters: only difference is mass
Isochrones: Lines of ‘constant age’ for stars of different masses
M. S. LIFETIME for STAR at TURNOFF = AGE of CLUSTER
Star cluster website
Star clusters are useful to: 1. Verify stellar evolution models 2. Determine distances to nearby galaxies 3. Determine chemical composition of universe in the very distant past
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- Do
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- Between the stars chapter 26
- Why were annemarie ellen and kirsti stopped by the soldiers
- Chapter 19 section 2 the life cycle of stars answer key
- The stars and i chapter 21
- The stars and i chapter 19
- Present continuous interrogative