The parallax angle for a star is 0.015 seconds of arc.
What is the distance in parsecs (pc) of the star from the Earth?
67 pc
133 pc
220 pc
2.1 × 1018 pc
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The parallax angle for a star is 0.015 seconds of arc.
What is the distance in parsecs (pc) of the star from the Earth?
67 pc
133 pc
220 pc
2.1 × 1018 pc
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In astronomy, distance can be measured in different units.
Which one of the following distances is the largest?
4.22 × 1016 m
1.91 pc
3.42 ly
593 AU
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Which two quantities are related in Hubble’s law?
Distance and mass of galaxies.
Velocity and intensity of galaxies.
Distance and velocity of galaxies.
Distance and red shift of stars in our galaxy.
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An astronomer analyses the light from a distant galaxy.
One of the spectral lines in the spectrum observed from the galaxy has wavelength 610 nm.
The same spectral line has a wavelength of 590 nm when measured in the laboratory.
What is the speed of this galaxy?
9.8 × 106 ms–1
1.0 × 107 ms–1
2.9 × 108 ms–1
3.0 × 108 ms–1
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A spectral line corresponds to a wavelength λ1 in the laboratory. The same spectral line observed in the spectrum of a receding galaxy corresponds to a wavelength λ2.
The distance of the galaxy from the Earth is d. The speed of light in a vacuum is c.
What is the correct expression for the Hubble constant H0?
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Recent analysis of the data collected from the Hubble and Gaia telescopes gave the Hubble constant a value of 73.5 kms–1 Mpc–1.
What is this value, written to 2 significant figures, in s–1?
2.4 × 10–21 s–1
2.4 × 10–18 s–1
2.4 × 10–12 s–1
2.4 × 1021 s–1
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