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 regarding the bending of light by mass or energy.
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Questions regarding bodies smaller than planets but larger than other bodies, that do not meet at least one of the IAU's criteria for being a planet.
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Questions about the outermost layer of a body.
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Questions regarding the movement of an object at a given speed and direction, often related to the concepts of orbital velocity and escape velocity.
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Questions about the water molecule (composed of two atoms of hydrodgen and one atom of oxygen) and its detection in celestial objects.
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Stellar dynamics describe the branch of astronomy that studies the regularities in the motions of stars in gravitational fields of a stellar systems, as well as the evolution of stellar systems.
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Questions regarding disks of gas, dust, and plasma around a central object, such as a black hole, which takes in the matter.
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Questions about observations performed without the aid of any optical instrument.
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Questions regarding an event where the Earth goes between the Sun and the Moon and casts a shadow on the Moon.
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Questions about spacecraft journeying to other stellar systems.
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Questions about the NASA space observatory famous for finding potentially habitable exoplanets. Do not use this tag for questions about Johannes Kepler.
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Questions about reflecting telescopes using a concave primary mirror and a flat diagonal secondary mirror.
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Questions about the "Goldilocks Zone" around a parent star where conditions are just right for the potential of life developing.
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Questions regarding the inner portion of a galaxy; in the Milky Way, this is the area around Sagittarius A*.
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Questions about planets that do not orbit around a star. These planets travel through space.
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Questions about electron degenerate stellar remnants.
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Questions regarding matter in its gaseous state, and how it behaves in astronomy (e.g. forming stars in giant molecular clouds).
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Questions about the simplest and most abundant element in the Universe.
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Questions regarding the material at or near the center of an astronomical object.
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Questions regarding grouping objects together based on one or more shared property.
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a disk-shaped belt of icy debris orbiting in the outer solar system, lying beyond the orbit of Neptune and extending to a distance of about 50 astronomical units, containing thousan…
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Questions on any of the 5 locations where a small object can maintain a stable orbital configuration with respect to two co-orbiting larger bodies.
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Questions regarding how bright an object appears to be.
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Questions related to earth processes or related processes and principles.
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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 regarding structures designed to aid in the observation of astronomical objects.
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