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Astronomy Presentation: Stars
Transcript of Astronomy Presentation: Stars
Madison Martin & Ozair Rajani
Tour of the Stars!
Words We Think You Might Find Confusing:
Let's Get Started on our Journey
The Evolution of Stars
Congratulations! It's a Star!
Analyzing Star Colour
Welcome friends, to the tour of the stars! We will be your hosts today. Located on your left side, you will find pamphelts to help you along the way of our journey! However, the pamphlets are fill in the blanks. Thank you for choosing Cheapo Star Tours!
Did you know that a star is made up of hot gases, with a core like a thermonuclear reactor? And that space is not empty; it is filled with interstellar matter, which is made up of gas and dust. The dust accounts for only about 1 percent of the total mass of interstellar matter, but even at such a small amount, interstellar dust makes it difficult for astronomers to see the light from distant stars. But not too worry! Astronomers have found a way to “see” through the dust, and into stellar nurseries.
gravity pulls together gas & dust from a nebula to form a protostar
protostars with a small mass may shrink away and never form a star
the star begins to glow and radiate energy EVERYWHERE as electromagnetic waves
A star's colour reveals information about the star's temperature and composition.
Star's exist in a range of colours that can even reveal wether the star is moving toward or away from Eath and how fast it is moving
The Hertzsprung-Russell Diagram
Many stars visible from Earth are bigger than the Sun
The largest star discovered so far is VY Canis Majoris. It's full size, still being debated, is suggested that it has a diameter 3000 times larger than that of the sun
This star was first catalogued by Lalonde in 1801. Its radius was measured by Roberta Humphreys in 2006.
Colour and Temperature
Like a stove element, the colour can determine the temperature
Astronomers use the evidence of a star's colour to tell them what the surface temperature likely is.
Corresponds with the Hertzsprung-Russell diagram
Ejnar Hertzsprung and Henry Norris Russel found out that stars do not stay the same forever.
Stars follow a clear pattern of evolutionary stages.
There are stars whos energy comes from converting hydrogen to helium. When those stars age and start to run out of hydrogen, they begin to expand and undergo changes in temperature, colour and luminosity.
Red stars are relatively cool (average of 3000* C)
Yellow stars are relatively hot (average of 6000* C)
Did you know?
The core of a protostar is so hot (10 000 000°C) that hydrogen atoms "fuse together" to form large single atoms! This process is called "nuclear fusion".
1 light year = 9.4605284 × 10 to the power of 12 kilometers
The sun is the closest star to earth and is 4.6 billion years old
The solar system takes 200-250 million years to orbit around the milky way.
Blue stars are the hottest of all (ranging from 20000* C - 35000* C)
Depending on the mass of the protostar, there are 3 main paths of life for a star
Low Mass Stars:
- dim cool red dawrf for most of their life (100 billion years)
- burn in hydrogen very slowly
- end: hot dim white dwarf that burns out quietly
Colour and Composition
Star light can be analyzed through a spectroscope.
The spectral lines that appear indicate that some of the light's wavelenghts have been absorbed by the particular gases in the star's composition.
Each element has different spectral lines
By knowing elements spectral patterns, astronomers can analyze any star's spectrum (can determine what gases make up the star's atmosphere)
Colour and motion
Spectroscopes can also to analyze the star's relative movement.
To understand this concept you must learn the Doppler effect.....
Light energy travels in waves.
Imagine light waves as in waves produced from a duck swimming.
The wavelenghts become compressed in the front of the duck and the wavelenghts behind the duck stretch out.
The change in wavelenghts because of motion is called the doppler effect.
Astronomers combine the Doppler effect with their knowledge about the technique of measuring the spectral red shift of thousands of stars to analyze the pattern of light emitted by individual stars
blue wavelenghts are shorter = towards you
red wavelenghts are longer = going away
Interstellar matter: The material that fills space, made up of gas and dust
Star: An object in space made up of hot gases, with a core that is like a thermonuclear reactor
Supernova: A dramatic, massive explosion that occurs when a large, high mass star collapses in on itself
Black hole: A large sphere of incredible tightly packed materials with an extraordinary amount of gravitational pull created when a star collapses into itself, called: “black” because nothing, not even light, can escape the powerful gravitational field.
Doppler effect: the change in wavelength in radiation or sound that occurs because of the movement of the source to an observation
Nuclear fusion: The process in which the nuclei of atoms fuse together to form larger single atoms, creating an enormous amount of energy
Spectroscope: An optical device for observing a spectrum of light or radiation from any source.
High Mass Stars:
- at least 12x more massive than the Sun
-consume fuel the fastest = large size, rapid growth (1 million km in width) and burn out faster (7 billion years)
- death: collapse, massive explosion (supernova)
-stars 12x - 15x more massive than the Sun: supernova to neutron star (100 000 000°C & take a trillion years to cool.)
-stars 25x more massive than the Sun = black hole
because star was so dense = extraordinary gravitational pull, nothing can (not even light!) can escape
Intermediate Mass Stars:
- ex. Sun
- burn hydrogen fuel faster
- live for 10 billion years
- death: expands into red giant, collapses in a white dwarf and then become a black dwarf (dense,dark black body of oxygen and carbon)
Video:http://www.youtube.com/watch?v=HEheh1BH34Qlink to video (star size)
Low Mass Stars, Intermediate Mass Stars and High Mass Stars
Information : BC Science 9 Textbook
Images: www.prezi.com (Welcome and Colour and temperature)
Images: http://www.spacetelescope.org/images/opo0432d/ (Words we think you might find confusing)
Images: https://en.wikipedia.org/wiki/Star (lets get started on our journey)
Images: http://blog.signalnoise.com/2008/03/16/protostar-cosmique/ (Congratulations! It's a Star!)
Images: http://www.howtogeek.com/howto/18658/desktop-fun-nebula-wallpapers/ (The evolution of stars)
Images: http://www.astronomyknowhow.com/hydrogen-alpha.htm (Colour and Composition)
Images: http://www.123rf.com/photo_6222879_duck-swimming-in-water-stock-photo.html (Colour and motion)
Images: http://megancarter2.wix.com/properties-of-stars?_escaped_fragment_=__hertzsprungrussell-diagram (Hertzsprung-Russell Diagram)
Images: http://noelwalker.wordpress.com/2010/01/23/94/ (pamphlet)
Video: http://www.youtube.com/watch?v=xVk48Nyd4zY(High Mass Stars)
Video: youtube.com/watch?v=80eMTnnLjhs&list=PLF4812950B86EEFB49(Congratulations! Its A Star!)
Video:http://www.youtube.com/watch?v=awzk6YbP7QA(HIgh Mass Stars)
animation of a supernova
How stars are made
Neutron Star Formation; Black Hole Formation
What is the Doppler effect?
What is the closest star to Earth?
If the sun died, how would it likely die?
What colour is the hottest star type?
What diagram describes the stars temperature?
Please wait until the starship lands before taking off your seatbelt. Thank you again for choosing Cheapo Star Tours. Please tip your star hosts generously!