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 about the "Goldilocks Zone" around a parent star where conditions are just right for the potential of life developing.
Questions about the water molecule (composed of two atoms of hydrodgen and one atom of oxygen) and its detection in celestial objects.
Questions about reflecting telescopes using a concave primary mirror and a flat diagonal secondary mirror.
Questions about observations performed without the aid of any optical instrument.
Questions about quasi-stellar radio sources, active galactic nuclei that are far away and quite old.
Questions regarding two objects colliding into each other with considerable force.
Questions about planets that do not orbit around a star. These planets travel through space.
Questions about streams of plasma released from the Sun or other stars (stellar winds).
Questions regarding structures designed to aid in the observation of astronomical objects.
like stars but never achieve nuclear fusion because they are too low-mass.
Questions regarding the inner portion of a galaxy; in the Milky Way, this is the area around Sagittarius A*.
Questions regarding disks of gas, dust, and plasma around a central object, such as a black hole, which takes in the matter.
Questions regarding the large "cloud" of small bodies that forms a sphere around the solar system.
Questions regarding the process of assigning an identifying set of characters to an astronomical object.
Questions regarding the theory of gravity as proposed by Newton, in which the force of gravity depends only on the mass of bodies, a constant, and the distance between them, and depends on one equatio…
Questions regarding the large-scale change of orbits over time, as in the Nice Model.
Questions regarding Neptune, the 8th and furthest major planet orbiting Earth's sun.
For questions about objects or phenomena outside Earth, generally on other planets.
Questions about the branch of astronomy that studies the regularities in the motions of stars in gravitational fields of stellar systems, as well as the evolution of stellar systems.
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.
Questions relating to the discovery of a new ninth planet (not Pluto) hypothesized in the Solar System.