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.

Atmospheres of planets, moons, and other solar system bodies excluding stars. For those, use "stellar-atmosphere" instead. For influences of Earth's atmosphere on astronomical observations use "atmosp…
182 questions
Questions related to the evolution of stars.
179 questions
Questions about the increase with time of distance between two distant points in the Universe.
177 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.
172 questions
Questions regarding the currently prevalent cosmological model for the origin of the universe.
170 questions
Questions related to the phenomenon whereby electromagnetic radiation (such as visible light) generated by an object moving away from an observer will have increase in wavelength (i.e. shifted toward …
165 questions
Questions regarding the most massive examples of black holes that typically reside at the centers of galaxies.
164 questions
Questions about the source or effects of the matter that makes up 85% of the matter in the universe but appears to only interact gravitationally.
160 questions
Waves in spacetime formed by the acceleration of massive bodies. A passing wave causes spacetime to be stretched and squashed by a very small amount. Typically we can only detect the most energic grav…
157 questions
Questions on time, the indefinite progress of events in the Universe.
155 questions
Questions regarding a degenerate star that is mainly composed of neutrons.
153 questions
Questions regarding a pair of stars that are gravitationally bound and orbit around their barycenter.
152 questions
Questions regarding the property of astronomical objects that determines their inertial resistance and gravitational interaction with other bodies.
151 questions
Questions involving reference frames, time scales, and how they are determined. Not for general Astronomy 101 questions.
146 questions
Questions about the complete or partial blocking of the sun by the moon.
143 questions
Questions about the observed frequency range of the electromagnetic radiation of a celestial object.
143 questions
Temperature is a measurement of the average kinetic energy of the molecules in an object or system. In simpler words: it's the degree or intensity of heat present in a substance or object that is comm…
135 questions
Questions about the parameters needed to specify the characteristics of an orbit.
132 questions
Questions related to the physical processes involved in or to the observations of the process of forming a star.
130 questions
Questions about positions of objects in the sky, either relative to a fixed coordinate system like the equatorial and ecliptic coordinate systems, or relative to an observer's point of view.
130 questions
Behaviour and properties of light, and its interaction with matter, particularly in detection of light.
122 questions
Questions about the processes, theories and evidence for the formation of planetary bodies.
119 questions
Questions regarding specific terms, names, or naming conventions.
119 questions
Questions about using the Python programming language to solve astronomical problems. General questions about Python are off-topic but might be asked on Stack Overflow.
119 questions
For astronomy questions with a heavy mathematical component, more than simple formulas. For regular mathematics question, visit our sister site Mathematics Stack Exchange.
118 questions
Questions regarding magnetic fields.
115 questions
Questions regarding the region of space containing all the objects that we can detect using any method of observation.
114 questions
Questions about inducing chemistry, physics, and many more branches of science into astronomy.
114 questions
Questions regarding the planet Venus, the second planet from the Sun.
113 questions
Questions regarding the motions of celestial objects.
112 questions
Questions regarding the measurement of the amount of light coming from astronomical objects.
111 questions
Questions about the apparent force stretching a body towards and away from the center of mass of another body due to the variance in acceleration due to gravity
107 questions
Questions regarding massive planets composed of layers of gases, such as hydrogen and helium, surrounding a solid/liquid core.
106 questions
Questions regarding telescopes in orbit around Earth, such as the Hubble Space Telescope.
104 questions
Questions regarding the Hubble Space Telescope, a visible light telescope orbiting Earth.
104 questions
Questions regarding the amount of energy produced by an object per unit of time.
102 questions
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