Classifying Stars
4 marks · NormalThe Milky Way is the galaxy that contains our Solar System.
Describe the shape of the Milky Way as seen from above.
Where is the Solar System located within the Milky Way galaxy?
Explain why we see many stars in the direction of the Milky Way band in the night sky.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
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(a) Spiral · must show mentions spiral shape
(b) About two-thirds of the way out from the centre along one of the arms · must show not at the centre; two-thirds out
(c) When we look along the plane of the Milky Way, our line of sight passes through a greater number of stars concentrated in the spiral arms, making the Milky Way band appear brighter with many stars. · must show looking through plane/arm, stars concentrated
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Marking points
B1 (a) · 1 mark · Identifies spiral shape.
B2 (b) · 1 mark · Correctly describes Solar System as being about two-thirds of the way out along a spiral arm.
B3 (c) · 2 marks · Explains that looking along the dense plane/arm of the galaxy means we see many stars packed together.
Worked solution
a) The Milky Way galaxy is spiral in shape.
b) Our Solar System is about two-thirds of the way out from the centre of the galaxy, on one of its spiral arms.
c) We see many stars in the direction of the Milky Way band because we are looking through the dense plane of the galaxy, toward a large concentration of stars.