Year 10 The mysterious Universe Chapter 6 (JacPlus)
Access Code 2JUW
Access Links
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Key Concepts
  1. Observing the night sky
  2. The Sun
  3. Stability and Change: the stars
  4. Stability and Change: the changing Universe
  5. How it all began
  6. Eyes on the Universe
  7. Anybody out there??

*Science Understanding
Science Quest 8
1 6.1 Observing the night sky Suggestions:
Investigation 6.1: the effect of Parallax

INtroductory video
Understand and Inquiring questions 1 to 12

Worksheet 6.1 Observing stars


Parallax - Wikipedia, the free encyclopedia
3 Parallax error in measurement instruments; 4 Photogrammetric parallax ... cues through viewpoint-shifting animation rather than through binocular vision.
Words to Learn
Constellations, galaxies, nebulae, parallax
2 6.2 The Sun Youtube video:
Understanding & Inquiring 1 to 8

Worksheet 6.2 The sun and nuclear fusion
Words to Learn
Nuclear fusion, corona, sunspots, aurora borealis, aurora australis, ionosphere
3 6.3 Stability and Change: the stars Inquiry Investigation 6. 2: Heat produced by compressing a gas

Weblink: Star evolution ( Good to help understand star lifecycles)

How big are we compared to the universe?
Understanding and enquiry

6.3 The brightness of stars
6.4 Star Life cycles

try this quizlet
Words to Learn
Protostar, magnitude ,apparent magnitude, absolute magnitude, main sequence, red giant, pulsating star, planetary nebula, white dwarf, supergiants, supernova, neutron star, black hole.
4 6.4 Stability and Change: the changing Universe Inquiry investigation 6.4 Doppler effect Understanding and enquiry

Worksheet 6.5 The expanding Universe


The Animation of the Doppler Effect.

Here is a longer one with some explanation - the first 3 minutes are the best
Words to Learn
Doppler effect, frequency, spectrum, wavelength, red shift, blue shift,
5 6.5 How it all began Elesson: the expanding universe
Elesson Entropy: Is the end of Universe nearer than we think?
Understanding and enquiry

Worksheet 6.6 The big bang
Words to Learn
Cosmology, big bang theory, absolute zero,
6 6.6 Eyes on the Universe Research Task: Research a Telescope and find out the following
Its location and size
what is it used to look for
What discoveries have been attributed to this telescope
who uses this telescope?
what are they working on now?

Present your results on an A4 page that includes pictures that show how the telescope operates and answers these questions.
Understanding & Inquiring
ques 1, 3, 4
Ext ques 2, 5, 6

Size in the universe

Try this revision quizlet about the universe

Catalyst program "the Universe" short video -great revision.
Words to Learn
Electromagnetic radiation, radio telescopes, quasars ,pulsars, ultraviolet radiation,, infra-red radiation, X-rays
7 6.7 Anybody out there?? Inquiry 6.5 Modeling a wobbling star Understanding and enquiry

Worksheet 6.7 telescopes
Words to Learn
Radio astronomy
History of atronomy the last 50 yrs from Click view

What do we know about the universe?

contains lots of galaxies. The galaxies contain lots of stars., constellations or groups of stars, and some stars have planets orbiting them, an example is our solar system inside the Milky Way . The Milky Way is in the Virgo super cluster of galaxies.
the difference between a star and a planet. Stars emit their own light because they are undergoing nuclear fusion reactions . Planets orbit stars and reflect light.
age of univers is 13.8billion years old
expanding . At an accelerated rate.
big bang theory is said to explain the start of the universe
billions of earth like planets
until 400 years ago astronomers thought earth was the centre of the universe
hydrogen most abundant element in the universe
made of matter, dark matter energy and dark energy
time is measured in earth years but distance is measured in light far light travels in a year.

Solar systems versus constellations

solar systems is a pattern of planets orbiting the sun. A constellation is a group of stars that make apTtern when viewed from earth. Some common examples include Orion, southern cross Virgo, Gemini,

Clouds of luminous gas, exploding stars and nebulae

The Sun

The sun is a star. It makes its own heat and light and cosmic radiation through the process of fusion. Fusion is a chemical reaction where two smaller light atoms combine to make a heavier atom. In this nuclear reaction there is no waste. The main element being formed in this reaction is Helium because tiny hydrogen atoms are being forced together to make the Helium.

Features on the sun include:
solar flares - these are huge explosions of gas that erupt 500,000km into space.
Sun spots - these are cool areas on the sun that appear as dark spots.
Corona- this is the light ring around the sun.

Inside the sun there are some heavier elements that make up the sun's core but this is surrounded by the burning gas .
The Structure of the Sun and Solar Events this is a short movie

q2 page 235 =What are sunspots -
q6 page 235 - extreme conditions of heat and pressure are required and we can't replicate this on earth as yet.

Life cycle of a star.
here is a simplified diagram

here is a short movie from NASA
This NASA video segment describes the life cycle of a star. Viewers learn about the opposing forces on a star and the ways in which these forces change over time to create a red giant. The video also discusses what will happen when the sun becomes a red giant, evolves into a white dwarf, and eventually ends its life as a black stellar corpse.

Lifecycle of a Star
Duration: 4 minutes 18 seconds
> View QuickTime [14MB]



How can we tell the temperature of a star by looking at it through a telescope?
Because of its colour we can measure its frequency and wavelength and this can be matched to it temperature.

Apparent magnitude - how bright something is as we look at it from earth eg the sun is -27 the moon is -13 (the sun makes its own light from nuclear reactions the moon only reflect light like a mirror) Rigel in the constellation Orion +0.11 - Our naked eyes can see up to an apparent magnitude of 6.

Absolute magnitude - is a measure of the amount of light emitted - eg the sun +4.7 Rigel in the constellation Orion is -7.5 (the smaller the number the greater the magnitude -ie brighter eg Rigel is brighter than the sun in absolute terms BUT it appears to us on earth that the Sun is brighter than Rigel)

How can we tell if stars are moving away from us? We see a change in their Frequency due to the Doppler effect

The Doppler effect and Sound
a sound moving towards you sounds higher as it passes and continues to move away it sounds lower. this is because as the sound moves toward you the frequency appears to increase hence the higher pitch due to the speed of sound having the speed of the sound source added to each other,

A shift to lower or ‘redder’ frequencies is called a red shift and results from a star's movement away from the Earth.

A shift to higher or ‘bluer’ frequencies is called a blue shift and is caused by a star's movement towards the Earth.

the astronomer Edwin Hubble and is now referred to as Hubble's law. This law states that the further away a galaxy is, the greater is its red shift and so the faster it is moving away from us.


How do we know how fast the universe is expanding?
Audio file:

Dr KarlDr Karl's Great Moments In Science

A brief history of the universe

The Science show
Keppler gets the wobbles

New Telescope Launched


(b) Explain the meaning of parallax in relation to the apparent motion of stars.

(c) Before 1837 it was believed that all stars existed on a transparent celestial sphere at a fixed distance from the Earth. How did the observation of parallax of close stars change this view?

(d) Outline the motion of the stars as seen by an observer on Earth during the time taken to travel from X to Y.

Star info
  1. Size: 2896819.2 km
  2. Brightness: Magnitude of 1.44. 24.7 x the suns luminous.
  3. Distance: 8.6 light years away from the sun
  4. Constellation: Canis Majoris (The Dog)
  5. Location: Northern hemisphere – in the south east – south – or south west on evenings from winter to mid-spring.

  1. Size: Not found
  2. Brightness: 2.6
  3. Distance: 88.2 light years
  4. Constellation: Zeta/Sagittarius
  5. Location: Southern sky
By Christina Heng 10D

Sirius (star) – Jenny Schaumann10D

Sirius is the also called the dog star, and the brightest star in our night sky. Sirius’ colour is observed to be mostly white or blue, but it is sometimes called the rainbow star because many observations of different colours.
Its brightness is estimated to be around 1.42 in magnitude. The mass of Sirius is around 2.2 million. In size, it is around 2,380,001 km in diameter. From mid-northern latitudes (such as the U.S.A), Sirius rises in the southeast, arcs across the southern sky, and sets in the southwest.
In December, Sirius rises in mid-evening. By mid-April, Sirius sets in the southwest in mid-evening. Sirius is part of the Canis Major constellation. Sirius is 8.611 light years away from Earth.

Alpha Centauri (star)
Alpha Centauri
Alpha Centauri
Alpha Centauri is 4.3 light years away. It is the closest star to the solar system. It is the brightest star in the constellation Centaurus. Alpha Centauri is a triple star, and its combined visual magnitude of -2.7 makes it the third brightest star in out night sky. Its combined mass equals to 2.07 million.
In the Northern Hemisphere, Alpha Centauri is located very far to the south on the sky’s dome. The cut-off latitude is about 29 degrees. People in the Northern Hemisphere might see Alpha Centauri at roughly 1 a.m. (local Daylight savings time) in early May. By early July, the system reaches its highest point to the south at nightfall.
In Australia and much of the southern hemisphere, Alpha Centauri is circumpolar, meaning that it never sets.
a) Size: diameter approximately 2.9 million km
b) Brightness: -1.44 magnitude
c) Distance from earth: 8.611 light years
d) Constellation: Canis Major (Greater Dog)
e) Where in the sky you would find it: Found in the southern sky, to the left and below Orion constellation.

a) Size: diameter approximately 147,897,875 km
b) Brightness: 1.1 magnitude
c) Distance from earth: 33.72 light years
d) Constellation: Gemini
e) Where in the sky would you find it: Found in the north-western sky, in the northern constellation of Gemini

Size: has a radius of 650,988,000 km, and is about 1000 times larger than our own sun.
Brightness: 75,000 times greater than the sun and has a magnitude of 0.58 (Var 0.3 -> 1.2) and an absolute magnitude of -5.14.
Distance from the Earth: 430 light years.
Constellation its part of: Orion
Where in the sky would you find it: Eastern sky at about 8pm. Generally the viewing of Betelgeuse indicates the start of winter.
Alpha Centauri
Size: It has a solar mass of 1.100 and the solar radius of 1.227
Brightness: magnitude of -0.27
Distance from the Earth: 4.367 light years
Constellation it is part of: Centaur
Where in the sky would you find it: In the Southern hemisphere throughout the year
Suma Sreedhar 10D

bronte howlett 10 D


1. Size- 2.9 million km

2. Brightness- a visual apparent magnitude of −1.46

3. Distance from earth in light years- 8.611 light years

4. Constellation it’s a part of- Canis Major

5. Where in the sky you would find it- vertically above (10:00 am)


1. Size-950 x sun (2896819.2km size)

2. Brightness- 0.5

3. Distance from earth in light years- 642.5 light years

4. Constellation it’s a part of- Orion

5. Where in the sky you would find it- south (10:00am) elevation of 20 degrees into the sky

Sirius 2896819.2 km 1.44 magnitude 8.6 Light years Canis Major Northern Hemisphere. To the south east
Betelgeuse 550 to 920 times the suns diameter 0.42 magnitudes 640 Light Years Orion constellation Parys Drakopoulos