A tag is a keyword or label that categorizes your question with other, similar questions. Using the right tags makes it easier for others to find and answer your question.

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Questions about observation performed in the radio frequency range of the electromagnetic spectrum (between 10 MHz and 1GHz).
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Questions related to the phenomenon whereby electromagnetic radiation (such as visible light) generated by an object moving away from an observer will have increased in wavelength (i.e. shifted toward…
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Questions regarding the action of or an object rotating along an axis.
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Questions about Saturn, the 6th planet in Earth's solar system.
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Questions regarding the physical dimensions of a celestial object.
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Questions regarding the earthly Sun and objects orbiting it.
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Questions regarding the Sombrero Galaxy, also known as M104 or NGC 4594. It is an unbarred spiral galaxy, part of the Virgo constellation.
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The near-vacuum extending between the planets and stars, containing small amounts of gas and dust. Also called outer space to refer to the physical universe beyond the Earth's atmosphere.
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Space debris (also known as "orbital debris", "space junk", or "space waste") is the collection of defunct objects in orbit around Earth and includes everything from spent rocket stages, old satellite…
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Questions about the observed frequency range of the electromagnetic radiation of a celestrial object.
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Questions regarding large spheres of gas undergoing fusion.
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Questions related to the physical processes involved in or to the observations of the process of forming a star.