25.1. Standard candles
A subsection of Physics, 9702, through 25. Astronomy and cosmology
Listing 4 of 4 questions
State what is meant by luminosity of a star. The luminosity of the Sun is 3.83 × 1026 W. The distance between the Earth and the Sun is 1.51 × 1011 m. Calculate the radiant flux intensity F of the Sun at the Earth. Give a unit with your answer. F = unit Use data from to calculate the mass that is converted into energy every second in the Sun. mass = kg The radius of the Sun is 6.96 × 108 m. Show that the temperature T of the surface of the Sun is 5770 K. The wavelength λmax of light for which the maximum rate of emission occurs from the Sun is 5.00 × 10–7 m. The temperature of the surface of the star Sirius is 9940 K. Use information from to determine the wavelength of light for which the maximum rate of emission occurs from Sirius. wavelength = m
9702_m22_qp_42
THEORY
2022
Paper 4, Variant 2
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State what is meant by the luminosity of a star. A star in the constellation Canis Major is a distance of 8.14 × 1016 m from the Earth and has a luminosity of 9.86 × 1027 W. The surface temperature of the star is 9830 K. Calculate the radiant flux intensity of the radiation from the star observed from the Earth. Give a unit with your answer. radiant flux intensity = unit Determine the radius of the star. radius = m Explain how the surface temperature of a distant star may be determined from the wavelength spectrum of the light from the star.
9702_w22_qp_41
THEORY
2022
Paper 4, Variant 1
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State what is meant by the luminosity of a star. A star in the constellation Canis Major is a distance of 8.14 × 1016 m from the Earth and has a luminosity of 9.86 × 1027 W. The surface temperature of the star is 9830 K. Calculate the radiant flux intensity of the radiation from the star observed from the Earth. Give a unit with your answer. radiant flux intensity = unit Determine the radius of the star. radius = m Explain how the surface temperature of a distant star may be determined from the wavelength spectrum of the light from the star.
9702_w22_qp_43
THEORY
2022
Paper 4, Variant 3
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Questions Discovered
4