Star Clusters and Stellar Evolution

Star clusters are elegant and pretty things to see in a telescope, but that's not the whole story. We know that stars must change as they run out of hydrogen to burn in their cores, and those deep changes in the core of stars have observable consequences. So, we use HR Diagrams to map the changes and enormous computer simulations to test the physics. This is part of my complete intro Astronomy class that I taught at Willam Paterson University and CUNY Hunter.
en.wikipedia.org/wiki/Hertzsp...
Hertzsprung-Russell diagram
en.wikipedia.org/wiki/Hyades_...)
Hyades Star Cluster
en.wikipedia.org/wiki/Open_cl...
Open Clusters
en.wikipedia.org/wiki/Globula...
Globular Clusters
www.noao.edu/kpvc/Prog/cluste...
NOAO image gallery
archive.stsci.edu/cgi-bin/dss_...
The STScI Digitized Sky Survey
apod.nasa.gov/apod/ap070809.html
M67 on APOD
hubblesite.org/image/837/news_...
M80 Hubble Space Telescope
hla.stsci.edu/hla_edu.html
My lab on the Hubble Legacy Archive Educational Materials
en.wikipedia.org/wiki/Stellar...
Stellar Evolution
en.wikipedia.org/wiki/Main_se...
Main Sequence Lifetime
en.wikipedia.org/wiki/Turnoff...
Main Sequence Turn-off
www.astrophysicsspectator.org/...
The Hertzsprung-Russell Diagrams of Star Clusters
0:00 Introduction
0:44 The Hyades Star Cluster
3:55 The Two Types of Clusters
4:59 Open Clusters
5:40 Messier 11 in context...
6:46 The Wild Duck Cluster: Messier 11
7:57 The Pleiades; M45: The Seven Sisters
8:25 The Perseus Double Cluster
9:05 Messier 67
11:19 Messier 41
14:35 Globular Cluster Messier 55
15:24 NGC 2808
16:08 Messier 92
16:34 Globular Cluster Messier 13
17:39 Messier 80
19:13 NGC 5139: Omega Centauri
20:38 Stars in space versus stars in the HR diagram
21:09 M55 Color-Magnitude Diagram
22:27 The Main Sequence, Revisited
23:21 Stars Live their Lives out...
24:20 Progressive Evolution
25:14 HR Diagram of the Pleiades
26:04 M67 HR Diagram
27:38 HR diagram for the globular cluster 47 Tucanae NGC 104 is about
28:21 H-R Diagrams of a Model Star Cluster
31:25 HR Diagram for Globular Clusters
31:35 Main Sequence Turn-off
32:24 Conclusions
33:31 Observing Stellar Evolution in Star Clusters
33:51 REVIEW QUESTIONS

[@JasonKendallAstronomer]

Please see the remastered version of this video here: ruclips.net/p/PLyu4Fovbph6cytm2oy4ctBOLMpNlakQp3

[@raybo780]

I’ve been binge watching your vids for a couple weeks straight, thanks for these!

[@JasonKendallAstronomer]

Thanks please share them around on social media

[@luisjosemorales980]

these videos are gems!!!!, you should have millions of views on your vids

[@herladyweaver862]

Classmates: I see you. Follow The Weaver, and trust her voice.

[@roblee4297]

I'm thinking about the current age of the universe, being 13 billion years old. Wasn't it said in the past when we could only see 10 billion light years then the universe was 10 billion years old? Some time before that it was 8? I'm thinking could there be a good deal more objects much further out there that's yet to be found and thus keeps the age of the universe very much in question? ✨

[@JasonKendallAstronomer]

The age of the Universe is really not at all in question at this point. The science is well-settled in this regard. But, actually mapping the entire visible universe is likely not possible.