Stars: Crash Course Astronomy #26

Today Phil’s explaining the stars and how they can be categorized using their spectra. Together with their distance, this provides a wealth of information about them including their luminosity, size, and temperature. The HR diagram plots stars’ luminosity versus temperature and most stars fall along the main sequence, where they live most of their lives.

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Chapters:
Introduction: Stars 00:00
Stellar Spectra 1:07
Star Classifications 3:03
Why Are There No Green Stars? 4:00
Luminosity Depends on Size and Temperature 5:27
The HR Diagram 6:33
Main Sequence Stars 7:27
Other Stars on the HR Diagram 8:17
Review 9:50
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PHOTOS/VIDEOS
Hawaii sunset photo [credit: Phil Plait]

[LewisK]

19 years old and I've finally learned the age old question, "Why is the sky blue?" this is amazing

[blackmesa]

The editor did a stellar job. He is definitely the star here. I just wish it wasn't so bright.

[willemvanechelpoel]

the diagram shows how stars die. so it's actually a dieagram?

[truboo]

The intro was so freaking creepy!
"Oh... I know who you are..."

[nicjasno]

I could watch Phil talk about astronomy all day long!

[Codiliabra]

I keep coming back to this video! I just adore stars.

[soundslave]

Annie Jump Cannon. Possibly the best name in history.

[ragnkja]

OBAFGKM: Only Bad Astronomers Forget Generally Known Mnemonics.

[alfredomarquez]

So she was named Annie Jump Cannon? Are we sure she wasn't also a superhero?

[TheMathMog]

These astronomy videos, are some of the videos on youtube I absolutely look the most forward to! I am getting quite a strong passion for physics and especially astronomy, and these are great to help improve and brush up some of my knowledge on the subjects! Keep it up!

[geniusmp]

Without a doubt, one of my favorite topics in astronomy. I can't wait to see all the remaining detail. This is basically the topic about the ultimate ancestors of all life on Earth. And Earth itself.

[Kzku]

As a non-native english speaker, I had no idea Betelgeuse is pronounced "Beetle-juice" in english.
In my language(Russian) it's pronounced "Betel-gay-ze""

[shiminshamim]

This is seriously my favorite topic in astronomy. And I'm so glad you are making whole series on astronomy. I'm gonna watch it even when I'm on my death bed :) and my friends and family are going to tease me and call me geek/nerd. 

[paulharris]

I'm a truck driver I was just curious the distance of the Sun and the Moon related to the Earth this channel rocks I had to subscribe

[DJAIV]

Wtf happened to the exoplanet episode?

[Plunder]

A year after my degree in Astrophysics these videos are a great way to make sure that I remember some of the keys facts that are a part of this amazing subject! Thank you!

[Zman]

1:06 that... sounded crazy with headphones

[chaohongyang]

A funny tease about Annie:
Annie jumped into a cannon and got shot up to near the sun where she discovered that the sun emits different colors than other stars cuase of spectra!

[prasannanegalur]

By far the best series on astronomy on YouTube!!!

[Shortstuffjo]

I'm just glad to hear there's going to be more episodes!

I've been interested in astronomy for well over 10 years now and yet I've learned a bunch from this Crash Course series.

Keep making them and make them long!!