E1+INTRODUCTION+TO+THE+UNIVERSE

Back to IB PHYSICS > IB ASTROPHYSICS OPTION E1-E4 are the sections required for the SL option =INTRODUCTION TO THE UNIVERSE= NEW FILM!
 * E1 INTRODUCTION TO THE UNIVERSE || E2 STELLAR RADIATION AND STELLAR TYPES || E3 STELLAR DISTANCES || E4 COSMOLOGY || E5 STELLAR PROCESSES AND STELLAR EVOLUTION || E6 GALAXIES AND THE EXPANDING UNIVERSE ||

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media type="custom" key="15424606" [| MUSIC OF THE PLANETS!] VIDEO FROM THE GUARDIAN: [|HOW THEY COLOUR HUBBLE'S IMAGES] (did you realise it only produces black and white pictures?)

Outline the general structure of the solar system. SOLAR SYSTEM: The Sun is orbited by planets, moons, asteroids and comets.

PLANETS AND MOONS: Planets orbit their star with a slightly elliptical orbit. There are 8 planets around the Sun. Most planets have moons; Jupiter has more than 60

ASTEROIDS AND COMETS: Billions of rocky objects called asteroids orbit the Sun between the inner and outer planets. Comets are made of ice and rock and orbit the Sun with highly eccentric orbits, passing beyond the orbits of the outer planets and returning near to the Sun.

ELLIPTICAL ORBIT: Non-circular path which has the star at one focus and is called eccentric. A body in an elliptical orbit changes speed as it travels.

Students should know that the planets orbit the Sun in ellipses and moons orbit planets. (Details of Kepler’s laws are not required.) Students should also know the names of the planets, their approximate comparative sizes and comparative distances from the Sun, the nature of comets, and the nature and position of the asteroid belt.

Distinguish between a stellar cluster and a constellation.

STELLAR CLUSTER: A group of stars within a galaxy which are close to each other and held together by gravitational attraction.

CONSTELLATION: A pattern of stars in the sky as viewed from Earth.The stars are not necessarily the same distance away fro the Earth.

ASTRONOMICAL UNIT: The average distance between the Earth and the Sun (1AU = 1.5 x 10 11 m Define the light year. LIGHT YEAR: The distance that light travels in one year. 1 ly = 9.46 x 1015 m (1 ly = 63 000 AU) Compare the relative distances between stars within a galaxy and between galaxies, in terms of order of magnitude.  GALAXY: A group of stars held together by gravity. Typically contains 10 11 stars and is 10 5 ly across. Distances between stars approx. 10 0 ly. Distance between galaxies 10 6 ly. Shapes can be spiral, globular or irregular  [|WHAT THE MILKY WAY LOOKS LIKE]- blog post from Starts with a Bang, click the pic below  [|SUPERMASSIVE BLACK HOLES PODCAST] - Astronomycast.com

Describe the apparent motion of the stars/constellations over a period of a night and over a period of a year, and explain these observations in terms of the rotation and revolution of the Earth. APPARENT MOTION OF THE STARS: In 24 hours, the stars appear to rotate about the extension of the Earth’s axis. In one year, due to the tilt of the Earth, the night sky changes position. The nearby stars vary in direction against the background of distant stars. This is the basic background for stellar parallax. Other observations, for example, seasons and the motion of planets, are not expected.

**RESOURCES FOR THIS TOPIC**

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 * THE DEATH OF STARS - HUBBLECAST 52 ON YOUTUBE **