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Question
A unique characteristic of type O stars is ionized helium lines in its spectrum.Answer
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Related questions
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A galaxy with a blueshift is moving ________ Earth.
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The spiral arms are blue from the presence of Population ________ stars in them.
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B) 0.08%
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Why is the energy source for active nuclei like Seyferts thought to be compact?
A) The sources appear to be single stars in photos.
B) Their energy appears to be non-stellar synchrotron radiation.
C) The light can vary over short time intervals.
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In active galaxies, their central engines may be temporarily fed by
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Describe the cycle of life and death we observe in the spiral arms.
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Why aren't there young stars in the halo?
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What advantage do radio astronomers have over optical ones in mapping the entire Milky Way?
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Virtually the entire disk of the Galaxy has been mapped using the ________ wavelength.