Tags
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.
Questions regarding large spheres of plasma undergoing fusion.
941 questions
Questions about the techniques and practice of observing the night sky.
780 questions
Questions regarding the closest star to Earth, at the centre of the Solar System.
711 questions
Questions regarding an object 'falling around' another object, due to a combination of gravity and momentum.
642 questions
Questions regarding points of extremely high mass density, which creates an extremely strong gravitational field from which light cannot escape.
637 questions
Questions regarding Earth's only natural satellite. For questions about the natural satellites of other planets, use the tag [natural-satellite].
631 questions
Questions on astronomical objects orbiting a star massive enough to be rounded, not massive enough to cause fusion, and which have cleared its orbit of planetesimals.
623 questions
Questions regarding systems of large numbers of stars held together by gravity.
568 questions
Questions regarding the Sun and objects orbiting it.
542 questions
Questions related to the physical instruments for astronomical observations.
541 questions
Questions regarding the attractive force which exists between any two bodies of matter.
490 questions
Questions regarding the planet on which humans live; the third planet from the Sun.
470 questions
Questions involving the physics of the universe, especially the nature of astronomical objects, energy fields, and/or regions, rather than their positions or motions in space.
463 questions
Questions about the observation of celestial objects by non-professional astronomers.
417 questions
Questions regarding planets that lie outside the Solar System.
375 questions
Questions about the origin, history, evolution and fate of the Universe.
375 questions
Questions regarding all of time and space and its contents.
317 questions
Questions regarding electromagnetic radiation in the visible spectrum.
291 questions
Questions regarding relatively small rocky bodies in an orbit around the Sun.
266 questions
Questions regarding the amount of space between two objects, the units, or measurement thereof.
254 questions
Questions about observations performed in the radio frequency range of the electromagnetic spectrum.
243 questions
The application of ballistics and celestial mechanics to the practical problems concerning the motion of rockets and other spacecraft.
233 questions
Questions about photography of celestial objects by amateur or professional astronomers. Questions about photography of other objects are off-topic but might be asked on our sister site Photography St…
215 questions
Questions regarding the Milky Way Galaxy, the galaxy that Earth's solar system is in.
212 questions
Questions on systems to uniquely determine position of a point or other geometric element on a manifold such as Euclidean space.
201 questions
Questions regarding stars which increase suddenly in energy output due to an explosion which ejected much of its mass.
197 questions
Questions regarding the history of astronomy, including discoveries and scientists.
193 questions
Questions regarding Jupiter, the 5th and largest planet in the Solar System.
191 questions
Questions regarding the 4-dimensional background structure of our universe.
186 questions
Questions regarding the action of or an object rotating along an axis.
183 questions
Questions on celestial bodies that orbit planets.
180 questions
Questions about relativistic theory of gravity. General relativity describes gravity as a geometrical property of space and time.
175 questions
Icy bodies that usually consist of methane, water, and other materials that originate from beyond the jovian planets, and occasionally fall into the inner solar system giving off a massive tail as mat…
173 questions
Questions about the measurement of light waves whereby the wavelength is classified by its position in the electromagnetic spectrum.
170 questions
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.
169 questions