Low Mass Stars: Crash Course Astronomy #29

Today we are talking about the life -- and death -- of stars. Low-mass stars live a long time, fusing all their hydrogen into helium over a trillion years. More massive stars like the Sun live shorter lives. They fuse hydrogen into helium, and eventually helium into carbon (and also some oxygen and neon). When this happens they expand, get brighter, and cool off, becoming red giants. They lose most of their mass, exposing their cores, and then cool off over many billions of years.

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Chapters:
Introduction: Low Mass Stars 00:00
Hydrogen Fusion 1:21
Life Cycle of Low Mass Stars 2:22
Larger Stars (Like Our Sun) Live Shorter Lives 3:10
Fueled By Fusion 3:58
Red Giants 5:45
White Dwarfs 8:08
The Fate of the Earth 8:59
Review 11:07
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Want to find Crash Course elsewhere on the internet?

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PHOTOS/VIDEOS

[SynSauce]

Please don't ever change the general idea of your intro tune. As soon as I hear it my mind goes into learning mode like I'm pavlov's dog. Keep up the great work!

[TSMSQ]

My mind gets blown every single episode. WOW.

[jaimie]

I'd just like to thank you, and say that my daughter took an astronomy class in college, and she's learning much more from this series than she ever did in class. I can attest to this, since I audited several lessons. They were using a textbook from 2004 (and this was two years ago), and the teacher had absolutely no idea what she was doing. I felt kind of bad for her. I would have felt worse if I hadn't been paying so much money for it. 

I'm learning a great deal as well. I've always been interested in astronomy, astrophysics, and cosmology. I was too sick to attend college long enough to get to any of what I actually wanted to learn. It's always been a huge regret. So thanks for giving me the chance to learn more now. It means a lot to me.

[peteplaysmusic]

I think this is my favorite Crash Course series, I love every episode :)

[ptxaholic]

Phil, you're my hero. Thanks for not beating around the bush and telling us our impending doom. 💕

[AlmostEthical]

Phil, that was my favourite so far. I'm writing sci fi (with real science) and your sessions are super helpful and reliable. I've always felt that stars were underrated. The planets, being about 0.14% the solar system's mass, are just the largest chunks of the Sun's debris field, lying well within its extended atmosphere.

[jaybestemployee]

Besides well written content, Phil is really a great host, who speaks at optimum pace and tone for comfortable listening. He also makes appropriate jokes once in a while which is unlike other hosts of crash course who just happened to let jokes overrun their show and confuse the audience. Great job, Phil, keep it up!

[tylerkeller]

The fact humans are capable of comprehending this, is just as remarkable as the way the universe works. Incredible.

[herpsenderpsen]

it's amazing to think that the smallest stars live the longest

[barbaraleaweaver-mercado]

Thank you for this series. Because of it, I checked out a book from the library on astronomy, went to an observatory, and saw Saturn and two of its moons. Never too old to learn.

[renae]

"stars in the sky look prettyyy"
thanks phil

[fazergazer]

High mass star:
Does this planetary nebula make me look fat?

[NickGreyden]

So there was this new guy I never heard of coming over to do crash course about one of my favorite subjects. I was prepared to be disappointed. I love being proven wrong. This is by far my favorite crash course series and I desperately hope there is much much more coming.

[ssam]

Every episode my mind is blown. Please make episode on
1. Pluto and dwarf planets
2. Faux moons of earth
3. Ring system around planets/asteroids
5. Black holes
6. Proxima and alpha centauries and planets around them

[Desmolas]

This episode was fantastic. I've watched a thousand 1hr long TV documentaries that just show lots of pretty CG graphics and dont really explain the lifecycle of a star all too well. But this episode was perfect and i actually learned ALOT that i hope will stick =D

[CybranM]

Crash Course Astronomy is so freaking fun to watch

[MehediHasan-dlle]

Phil: Nothing lasts forever.
My broke economic situation: Hold my bear.

[audracox]

Literally so more helpful than my professors lectures. Watching these is the only reason why I'm not utterly drowning in AST 105 rn. Thank you!!!

[NickSibicky]

I'm so proud to be backing content like this on Nice job guys, keep it up!

[Harley]

I absolutely love crash course astronomy. I love all crash course episodes, but astronomy is my favorite. Phil, you do an amazing job and you make the astronomy lessons very interesting, though it helps that astronomy is like the most interesting subject in the universe already!