Stars are born from clouds of hydrogen and helium gas that collapse under gravity. When the cloud becomes dense and hot enough, nuclear fusion begins at its core, causing the star to shine. A star's properties like size, temperature, and color depend on how much gas was in the original cloud. The Hertzsprung-Russell diagram classifies stars based on these properties and tracks their evolution over millions or billions of years as they fuse elements until dying in a supernova or becoming a black hole or white dwarf.
Information for Primary School students on stars and constellations. This PowerPoint uses some slides from http://www.slideshare.net/winga1sm/star-powerpoint-3308182 and the rest has been created by me.
Information for Primary School students on stars and constellations. This PowerPoint uses some slides from http://www.slideshare.net/winga1sm/star-powerpoint-3308182 and the rest has been created by me.
'A star is a luminous sphere of plasma held together by its own gravity. The nearest star to Earth is the Sun. Many other stars are visible to the naked eye from Earth during the night, appearing as a multitude of fixed luminous points in the sky due to their immense distance from Earth. Historically, the most prominent stars were grouped into constellations and asterisms, the brightest of which gained proper names. Astronomers have assembled star catalogues that identify the known stars and provide standardised stellar designations. However, most of the stars in the Universe, including all stars outside our galaxy, the Milky Way, are invisible to the naked eye from Earth. Indeed, most are invisible from Earth even through the most powerful telescopes.'
1. How a Star is Born, Lives, and Dies Matt Frisco
2. Pre-Stellar Gas Clouds Hydrogen and Helium are the most abundant gasses in the Universe. They form a cloud due to gravity. Example of a gas cloud.
3. Functions of a Gas Cloud It gets bigger and starts to spin. Gravity draws more gas to it. The gasses are hydrogen, helium, and lithium. Spinning causes the cloud to condense. It spins faster and gets denser until it reaches critical mass.
4. A Star is Born The cloud gets smaller, denser, and hotter. Eventually hydrogen begins to fuse. 2 hydrogen atoms become 1 helium atom. This process releases light and heat energy. Then the star lights up.
5. Early Days of a Star Fusion continues in the core where its hottest. The size depends on how much gas was in the cloud. Temperature depends on how much gas is fusing. Bigger hotter stars fuse more. Smaller cooler stars fuse less.
6. Classifying Stars Stars are many colors, sizes, and temperatures. Characteristics of stars are dependant of each other. For example: Big stars are hotter and bluer.
7. Examples of Star Color Stars can have many colors The most common are yellow and white Blue are biggest and hottest Red and Orange are average
8. The Hertzsprung–Russell Diagram The HR Diagram groups stars. The diagram was created in 1910. The diagram tells us everything about stars. All the information helps us understand a stars lifespan.
10. What the Diagram Measures The sides measure the brightness, spectral class, temperature, and magnitude (size relative to our sun). The dots represent the stars. The colors of the dots are the colors of the stars. All of this information helps us understand a stars lifespan.
11. Types of Stars The curve shape through the middle are the main sequence stars. The bottom left are white dwarfs. The top right are red giants. The top left are blue super-giants.
12. Main Sequence Stars Most stars are currently main sequence. Main sequence stars are many colors and temperatures. Main sequence stars fuse hydrogen and helium and other light gasses. Stars jump in and out of the main sequence.
13. Other Stars Some stars live their whole lives off the main sequence. Some jump on and off. Some special stars are blue giants and white dwarfs. Blue giants are big, bright, and hot. White dwarfs are small, dim. and cool. Blue giants don’t live long and white dwarfs live long.
14. Lives of Stars Stars live for 5 million-10 billion years. Stars turn mass into energy. Stars fuse all elements up to Iron; but not heavier. Stars and nebula make up 98 percent of all matter. Life wouldn’t be possible without stars. Stars are usually at least 3 light years from each other.
15. Our Star The name of the Sun is Sol Sol is 4.6 billion years old It will live another 5 billion years It takes 8 minutes for light to reach Earth Sol can fit 1million Earths inside of it
16. Death of Stars When the star cannot fuse anymore it dies Small stars dim down and off Super-giants explode in a supernova After the supernova it collapses into a black hole Black holes are small and dense
17. References GLCE E5.2F -http://www.michigan.gov/documents/EARTHMMC_168211_7.pdf Web Resources Oracle ThinkQuesthttp://library.thinkquest.org/J002231F/Sun/factsaboutthesun.htm National Geographic http://science.nationalgeographic.com/science/space/universe/stars-article.html Universe Today http://www.universetoday.com/25145/interesting-facts-about-stars/ Picture references Published by Tonynetone, Star Colors (Self-given description), Taken Date August 21, 2010 (no upload date) via flickr, creative commons attribution license. Published by NASA Goddard Photo and Video, Hubble Reveals Heart of Lagoon Nebula, Taken Date July 15, 2010 (no upload date) via flickr, creative commons attribution license. Published by NASA Goddard Photo and Video, Sun’s Surface May 18, 2010, Uploaded June 21, 2010 via flickr, creative commons attribution license. Published by Wikimedia Commons, H-R Diagram afr.GIF uploaded May 16 2007, via Wikimedia Commons, Creative Commons Attribution Share-Alike License