Low Mass Stars: Crash Course Astronomy #29

Uploaded by admin on December 7, 2015 at 12:26 pm

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.

Crash Course Astronomy posters now available at DFTBA: http://store.dftba.com/products/crashcourse-astronomy-poster

Table of Contents
Low Mass Stars Live a Long Time 0:57
Larger Stars (Like Our Sun) Live Shorter Lives 3:10
Fueled By Fusion 3:58
How They Turn Into Red Giants 5:45

PBS Digital Studios: http://youtube.com/pbsdigitalstudios

Follow Phil on Twitter: https://twitter.com/badastronomer

Want to find Crash Course elsewhere on the internet?
Facebook - http://www.facebook.com/YouTubeCrashCourse
Twitter - http://www.twitter.com/TheCrashCourse
Tumblr - http://thecrashcourse.tumblr.com
Support CrashCourse on Patreon: http://www.patreon.com/crashcourse

PHOTOS/VIDEOS
Stars http://skycenter.arizona.edu/sites/skycenter.arizona.edu/files/n6522_32in.jpg [credit: Adam Block/Mount Lemmon SkyCenter/University of Arizona]
The Sizes of Stars http://www.eso.org/public/usa/images/eso1030c/ [credit: ESO/M. Kornmesser]
Fusion in the Sun https://commons.wikimedia.org/wiki/File:FusionintheSun.svg [credit: Borb, Wikimedia Commons]
Mega Flares http://scitechdaily.com/images/Swift-Mission-Observes-Mega-Flares-from-a-Mini-Star.jpg [credit: NASA’s Goddard Space Flight Center/S. Wiessinger]
Proxima Centauri https://www.spacetelescope.org/images/potw1343a/ [credit: ESA/Hubble & NASA]
Physics in the Core http://solarscience.msfc.nasa.gov/images/cutaway.jpg [credit: NASA / Marshall Space Flight Center]
Three Years of SDO Images http://svs.gsfc.nasa.gov/cgi-bin/details.cgi?aid=11255 [credit: NASA's Goddard Space Flight Center/SDO]
Sun & Red Giants http://kepler.nasa.gov/files/mws/kasc3.jpg [credit: NASA]
Sun as Red Giant https://commons.wikimedia.org/wiki/File:Sun_red_giant.svg [credit:Oona Räisänen, Wikimedia Commons]
Gone with the Wind https://www.eso.org/public/usa/images/wr124/ [credit: ESO]
Expanding & cooling https://www.cfa.harvard.edu/sites/www.cfa.harvard.edu/files/images/pr/2009-23/1/base.jpg [credit: ESO/L. Calçada]
Looking down a barrel of gas at a doomed star http://hubblesite.org/newscenter/archive/releases/1999/01/image/a/ [credit: The Hubble Heritage Team (AURA/STScI/NASA)]
Expanding star orbit http://www.nasa.gov/centers/goddard/images/content/415775main_earthlike-exoplanet-full.jpg [credit: SO/L. Calçada]
Red Giant Earth https://commons.wikimedia.org/wiki/File:Red_Giant_Earth.jpg [credit: Fsgregs, Wikimedia Commons]
Crab Nebula https://en.wikipedia.org/wiki/Crab_Nebula#/media/File:Crab_Nebula.jpg [credit: NASA, ESA, J. Hester and A. Loll (Arizona State University)]

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.

Crash Course Astronomy posters now available at DFTBA: http://store.dftba.com/products/crashcourse-astronomy-poster

—

Table of Contents
Low Mass Stars Live a Long Time 0:57
Larger Stars (Like Our Sun) Live Shorter Lives 3:10
Fueled By Fusion 3:58
How They Turn Into Red Giants 5:45

—

PBS Digital Studios: http://youtube.com/pbsdigitalstudios

Follow Phil on Twitter: https://twitter.com/badastronomer

Want to find Crash Course elsewhere on the internet?
Facebook – http://www.facebook.com/YouTubeCrashCourse
Twitter – http://www.twitter.com/TheCrashCourse
Tumblr – http://thecrashcourse.tumblr.com
Support CrashCourse on Patreon: http://www.patreon.com/crashcourse

—

PHOTOS/VIDEOS
Stars http://skycenter.arizona.edu/sites/skycenter.arizona.edu/files/n6522_32in.jpg [credit: Adam Block/Mount Lemmon SkyCenter/University of Arizona]
The Sizes of Stars http://www.eso.org/public/usa/images/eso1030c/ [credit: ESO/M. Kornmesser]
Fusion in the Sun https://commons.wikimedia.org/wiki/File:FusionintheSun.svg [credit: Borb, Wikimedia Commons]
Mega Flares http://scitechdaily.com/images/Swift-Mission-Observes-Mega-Flares-from-a-Mini-Star.jpg [credit: NASA’s Goddard Space Flight Center/S. Wiessinger]
Proxima Centauri https://www.spacetelescope.org/images/potw1343a/ [credit: ESA/Hubble & NASA]
Physics in the Core http://solarscience.msfc.nasa.gov/images/cutaway.jpg [credit: NASA / Marshall Space Flight Center]
Three Years of SDO Images http://svs.gsfc.nasa.gov/cgi-bin/details.cgi?aid=11255 [credit: NASA’s Goddard Space Flight Center/SDO]
Sun & Red Giants http://kepler.nasa.gov/files/mws/kasc3.jpg [credit: NASA]
Sun as Red Giant https://commons.wikimedia.org/wiki/File:Sun_red_giant.svg [credit:Oona Räisänen, Wikimedia Commons]
Gone with the Wind https://www.eso.org/public/usa/images/wr124/ [credit: ESO]
Expanding & cooling https://www.cfa.harvard.edu/sites/www.cfa.harvard.edu/files/images/pr/2009-23/1/base.jpg [credit: ESO/L. Calçada]
Looking down a barrel of gas at a doomed star http://hubblesite.org/newscenter/archive/releases/1999/01/image/a/ [credit: The Hubble Heritage Team (AURA/STScI/NASA)]
Expanding star orbit http://www.nasa.gov/centers/goddard/images/content/415775main_earthlike-exoplanet-full.jpg [credit: SO/L. Calçada]
Red Giant Earth https://commons.wikimedia.org/wiki/File:Red_Giant_Earth.jpg [credit: Fsgregs, Wikimedia Commons]
Crab Nebula https://en.wikipedia.org/wiki/Crab_Nebula#/media/File:Crab_Nebula.jpg [credit: NASA, ESA, J. Hester and A. Loll (Arizona State University)]

Comments

Eric Loesch says:

December 7, 2015 at 12:44 pm

Emo Phil was amazing.

Nicklas Hansson says:

December 7, 2015 at 12:54 pm

Is this guy by any change related to Adam Savage?

The similarities in both apperance and the way they talk is striking.

Adriano Kury says:

December 7, 2015 at 1:11 pm

Excellent video!

GokaiTitan says:

December 7, 2015 at 1:27 pm

This series are really helping me with my Astronomy class 🙂 Thank you so much everyone at CrashCourse!

Blue says:

December 7, 2015 at 1:51 pm

Thank you for that Interstellar quote Phil :D

Andrea Ramirez says:

December 7, 2015 at 2:03 pm

Life-saver

Colin Warn says:

December 7, 2015 at 2:29 pm

6:50 "At some point the core will contract…"

Why?

accordeonist says:

December 7, 2015 at 2:36 pm

oh gawd. So depressing.

joesette spinner says:

December 7, 2015 at 2:54 pm

watching YOUTUBE in science class crash course is great

Penny Lane says:

December 7, 2015 at 2:56 pm

Wait, if the Sun got 40% hotter just by the core getting denser, that means about a third of its luminosity doesn't come from fusion but just from the Sun passively collapsing in on itself? That's mind-boggling. I mean, that's the same heat source Brown Dwarfs use and you don't see them boiling Earth's oceans in a billion years. They just slowly cool and die.