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 quasi-stellar radio sources, active galactic nuclei that are far away and quite old.
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Questions about observation performed in the radio frequency range of the electromagnetic spectrum (between 10 MHz and 1GHz).
Tag for questions asking if fictional ideas are possible or correct
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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 about planets that do not orbit around a star. These planets travel through space.
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Questions regarding the action of or an object rotating along an axis.
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Questions regarding an object orbiting around another object due to the force of gravity.
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Questions about Saturn, the 6th planet in Earth's solar system.
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infinitely dense.
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Questions regarding the physical dimensions of a celestial object.
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Questions about computer programs that assist modeling and observing the dynamics of astronomy.
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Questions about the complete or partial blocking of the sun by the moon.
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Questions regarding the 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.