1. Stars
By Logan willis

2. What are stars?
Stars are luminous spheres of plasma that have their own gravity and have a fixed position in space.
They are extremely burning hot.
The nearest star to us is the sun.
They are made up of mainly hydrogen and helium, but have a little bit of other elements like oxygen and carbon as well.

3. What do stars do?
Stars burn by fusing hydrogen into helium. This is what gives them their light and heat.
They have a gravitational pull, and so they pull planets into orbit and create solar systems.
Stars in massive groups are called galaxies.

4. Types of stars
There are a few different types of stars. Some are yellow dwarf stars, red dwarf stars, red giant stars, blue giant stars, and supergiants.
Dwarf stars are smaller and giants are bigger, obviously.
Our sun is a yellow dwarf star, and it is the smallest star.
The biggest star VY Canis majoris, and it is times the size of our sun. It is a red hypergiant.
The brightest star in the earth’s night sky is Sirius.

5. Midway quiz Are you ready? Click for the answers again to confirm.
Time for a quiz!
Click for the answers!
What are the two main gases in stars?
How do stars burn?
What are massive groups of stars called?
Name 3 types of stars
What is the largest star?
What is the smallest star?
What type of star is our sun?
What is the brightest star in earth’s sky?
Hydrogen and helium
They fuse hydrogen into helium
Galaxies
Some types: Red dwarfs,
yellow dwarfs,
White dwarfs, blue giants,
red giants, supergiants
5. Vy canis majoris
6. Our sun
7. Yellow dwarf
8. Sirius

6. A star’s life
Stars last millions or even billions of years, but even they eventually die. The bigger the star, the shorter the life span because they burn their energy faster.
Stars are born when clouds of dust and gas have a gravitational disturbance, like a nearby supernova. Clumps begin to form in the cloud, and compress and heat up. Eventually, a protostar is formed, which is the core of the star.
The protostar heats up so much and collects so much dust and gas that it releases a massive amount of gas in the form of a jet, called a bipolar. The dust eventually clears up, and you now have a young star.
As stars get older, they slowly expand. Eventually, when their core runs out of hydrogen and helium, the star collapses and explodes, causing a nebula or supernova.
Nebulas become a white dwarf, then a black dwarf, and supernovas become neutron stars or black holes.
The oldest star is nicknamed Methuselah star, and is and estimated ± 0.8 billion years old. The youngest star is AU Microscopium and is only about 12 million years old. Our own sun is about 4.6 billion years old.

7. I couldn’t get the video embed to work, so go watch the video here:
(This is just a picture)

8. Hertzsprung-Russell diagram
Hertzsprung- Russell diagrams are diagrams that plots each star on a graph measuring the star’s brightness against its brightness.
It does not show star locations.
It was created by Ejnar hertzsprung and henry Norris Russell.

9. Final test
Click here to take the final test:

10. Conclusion
I hope you learned more about stars and our own sun. Thanks for watching!
Also, check out the show firefly because it’s awesome.
Go here for some flashcards to study: stars-loganw-flash-cards/?new