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.

Type to find tags:
× 17
Questions regarding the movement of an object at a given speed and direction, often related to the concepts of orbital velocity and escape velocity.
× 17
Questions about the water molecule (composed of two atoms of hydrodgen and one atom of oxygen) and its detection in celestial objects.
× 17
Questions regarding the large-scale change of orbits over time, as in the Nice Model.
× 17
Questions about observations performed without the aid of any optical instrument.
× 17
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.
× 16
Questions about the "Goldilocks Zone" around a parent star where conditions are just right for the potential of life developing.
× 16
Questions regarding disks of gas, dust, and plasma around a central object, such as a black hole, which takes in the matter.
× 16
× 16
Questions about reflecting telescopes using a concave primary mirror and a flat diagonal secondary mirror.
× 16
Questions regarding an event where the Earth goes between the Sun and the Moon and casts a shadow on the Moon.
× 16
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.
× 15
× 15 × 15
Questions about spacecraft journeying to other stellar systems.
× 15
Questions about the NASA space observatory famous for finding potentially habitable exoplanets. Do not use this tag for questions about Johannes Kepler.
× 15
× 15 × 15
Questions about planets that do not orbit around a star. These planets travel through space.
× 15 × 15
Questions regarding the material at or near the center of an astronomical object.
× 15
× 15
Questions about the simplest and most abundant element in the Universe.
× 15
Questions regarding matter in its gaseous state, and how it behaves in astronomy (e.g. forming stars in giant molecular clouds).
× 14
Questions regarding the inner portion of a galaxy; in the Milky Way, this is the area around Sagittarius A*.
× 14
Questions regarding grouping objects together based on one or more shared property.
× 14 × 14
Questions regarding how bright an object appears to be.
× 14
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…
× 14
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.
× 14
Questions about electron degenerate stellar remnants.
× 13 × 13
× 13
Questions related to earth processes or related processes and principles.
× 12
Questions regarding thermal energy and its effect on astronomical objects.
× 12
A measure of the ratio of an object's mass with its volume.
× 12
The corresponding particles of opposite charge to the particles of conventional matter (e.g. the positron is the antiparticle of the electron)