Binary and Multiple Stars: Crash Course Astronomy #34

Double stars are stars that appear to be near each other in the sky, but if they’re gravitationally bound together we call them binary stars. Many stars are actually part of binary or multiple systems. If they are close enough together they can actually touch other, merging into one peanut-shaped star. In some close binaries, matter can flow from one star to the other, changing the way it ages. If one star is a white dwarf, this can cause periodic explosions, and possibly even lead to blowing up the entire star.

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Chapters:
Introduction: Binary & Multiple Stars 00:00
Visual Binary Stars 1:45
Spectroscopic Binaries 3:05
Multiple Star Systems 4:15
Eclipsing Binaries 5:44
Contact Binaries 6:53
Stellar Novae 8:31
Review 10:50

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PHOTOS/VIDEOS

[ComandanteJ]

Every school should show this series to the students, and every science teacher should wear cool shirts like those Phil uses.

[PogieJoe]

I'm going to miss this series when it's inevitably over. It's by far my favorite Crash Course.

[schrodingerdiscovery]

Our sun is social distancing because of its corona.

[ullseye]

_"This makes them very important indeed, as you'll see in a future episode"_

Oh Phil - you tease, you.

[ashutoshsingh]

Kudos to the photographer who took time and went in space to take these amazing pictures

[opsimathics]

I wish these videos would get MILLIONS of views.

[Grivian]

Imagine living on a planet in the habitable zone in a sextuple star system

[mtalhakhalid]

our Sun is in long distance relationship :P

[rickogden]

I love Phil's obvious passion for the subject matter...reminds my of a speeded-up Carl Sagan

[ganaraminukshuk]

From CCA 31: Outgoing neutrinos slams into the star's outer layers and blows everything outwards, and the star explodes.

From CCA 34: Extra gas from a companion star gets dumped onto a white dwarf resulting in carbon fusion, and the star explodes.

I'm starting to see a theme here...

[DanThePropMan]

7:15 "This can make things really weird for them."

I smell a sitcom...

[sharanski]

I just went on a CrashCourse Astronomy binge watch!! Thank you so much for your videos, after the lunar eclipse this past weekend, I was excited to learn more about the sun, the stars, and our universe :) thanks for your hard work on these videos!!

[Killbayne]

"Used as eyesight test in ancient times"

Imagine one of then has better eyesight than the other and both be like "THERE IS A SECOND ONE CANT YOU SEE IT?"
-"nah you're just crazy"

[broghanhatesme]

Probably one of my favorite episodes yet. I've known about multiple star systems, but learning about contact binaries and the stellar novae at the end was really cool!

[pamelasimon]

Ms. Simon's Earth Science Class (8th-9th grade)
This is one of my favorite episodes. It made me think about planets in binary systems. A sky on a planet in a multi-star solar system would be amazing. There would be periods in the year where the other stars were closer and farther away or parts were there was no night because both sides of the globe would be cast in light. If the planets had moons they might have a constant shadow moving on the planet until it got out of that zone; maybe even a couple weeks of solar eclipses over and over again.
So many questions! Would some days be longer from the tidal effects of the other stars? How would comets and asteroids react in that system? How drastically would temperatures change on the planet as its star orbited around the others, if they would change that much at all?
I love astronomy because there are still so many questions to be asked, and with every question answered ten more take its place.
Rochelle Mann 9th grade

[WalleywolfIdaho]

This is by far the best educational series for amateur astronomers.... Thanks

[Demonkah]

Phil Plait you are surely one of my idols of all time!

[ZiePe]

6:30 'When the fainter star goes behind the brighter star, the light hardly drops at all' The graphic is showing the opposite, or am I missing something here?

[alfredomarquez]

Thursday is my favorite day of the week.

Also, hurray for next week episode on star clusters!

[EdWalzak]

One of the best things about our infinite universe is that there are countless objects for you to make CrashCourse Astronomy videos about. Well done yet again!