Starter quiz
- A ______ star fuses hydrogen in its core. It is stable for long periods of time (often billions of years).
- 'main sequence' ✓
- What type of star will the Sun change into next, after it stops fusing hydrogen in its core (in about 5 000 000 000 years)?
- red dwarf star
- white dwarf star
- red giant star ✓
- white dwarf star
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- Sort the following stages of a star's life, for a star similar in size to the Sun, into the order in which they take place.
- 1⇔nebula
- 2⇔protostar
- 3⇔main sequence star
- 4⇔red giant star
- 5⇔white dwarf star
- 6⇔black dwarf star
- What is a giant exploding star called?
- 'supernova' ✓
- What is a neutron star that is formed from the core of a supernova?
- a very large and hot white dwarf star
- an incredibly hot ball of plasma and gas
- an incredibly dense ball of atoms
- an incredibly dense ball of neutrons ✓
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- What is a black hole that is formed from the core of a particularly large supernova?
- the core of a massive star compressed to a few thousand metres across
- the core of a massive star compressed to a few hundred metres across
- the core of a massive star compressed to a few metres across
- the core of a massive star compressed to almost no size at all ✓
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Exit quiz
- Which of the following optical instruments can improve what we can see in space?
- binoculars ✓
- microscopes
- stethoscopes
- telescopes ✓
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- What makes a star appear to twinkle in the night sky?
- clouds
- moving air ✓
- gases around the star
- nebulae in space
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- What are the advantages of using a space telescope compared to a telescope on Earth?
- It is very expensive to construct and launch.
- It encounters no atmospheric distortion. ✓
- It can detect more types of radiation. ✓
- It is smaller in size.
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- How do Messier objects that can be seen with a telescope differ in appearance from stars?
- They are much brighter.
- They have distinct colours.
- They don't have sharp outlines. ✓
- Their brightness varies in a regular pattern.
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- What are absorption lines in a spectrum of light from a star?
- coloured lines that add together to make a visible spectrum
- black lines on a visible spectrum caused by a telescope
- black lines on a visible spectrum caused by gases around a star ✓
- black lines on a visible spectrum caused by air in Earth's atmosphere
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- What observation shows that redshift has occurred and that the wavelength of light from a distance galaxy has increased?
- there is less red light in the visible spectrum of the galaxy
- there is more red light in the visible spectrum of the galaxy
- absorption lines in its spectrum have lower than expected frequencies ✓
- absorption lines in its spectrum have higher than expected frequencies
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Worksheet
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Presentation
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Video
Lesson Details
Key learning points
- Telescopes extended what was visible after their invention in the seventeenth century.
- Images detected by telescopes in space are not distorted by effects of the Earth’s atmosphere.
- A galaxy is a group of hundreds of billions of stars, and there are many galaxies spread across the universe.
- A visible spectrum of light emitted from stars or galaxies shows dark lines of frequencies of light.
- Red shift is the movement of hydrogen lines towards the red end of the visible spectrum.
Common misconception
Stars twinkle (change brightness rapidly).
Explore the ideas that Earth’s atmosphere is made of moving air that refracts light from stars in changing directions to distort the light coming from stars.
Keywords
Space telescope - is a telescope positioned in space to avoid atmospheric interference and observe parts of the spectrum which cannot reach the Earth’s surface
Galaxy - is a collection of many millions or billions of stars held together by gravitational forces
Redshift - is the increase in the wavelength of light (and decrease in its frequency) cause by the movement of a star or galaxy away from us
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