Portal:Astronomy
The Astronomy Portal
Introduction![]() Astronomy is a natural science that studies celestial objects and the phenomena that occur in the cosmos. It uses mathematics, physics, and chemistry in order to explain their origin and their overall evolution. Objects of interest include planets, moons, stars, nebulae, galaxies, meteoroids, asteroids, and comets. Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation. More generally, astronomy studies everything that originates beyond Earth's atmosphere. Cosmology is a branch of astronomy that studies the universe as a whole. Astronomy is one of the oldest natural sciences. The early civilizations in recorded history made methodical observations of the night sky. These include the Egyptians, Babylonians, Greeks, Indians, Chinese, Maya, and many ancient indigenous peoples of the Americas. In the past, astronomy included disciplines as diverse as astrometry, celestial navigation, observational astronomy, and the making of calendars. Professional astronomy is split into observational and theoretical branches. Observational astronomy is focused on acquiring data from observations of astronomical objects. This data is then analyzed using basic principles of physics. Theoretical astronomy is oriented toward the development of computer or analytical models to describe astronomical objects and phenomena. These two fields complement each other. Theoretical astronomy seeks to explain observational results and observations are used to confirm theoretical results. Astronomy is one of the few sciences in which amateurs play an active role. This is especially true for the discovery and observation of transient events. Amateur astronomers have helped with many important discoveries, such as finding new comets. (Full article...) General images -The following are images from various astronomy-related articles on Wikipedia.
This is a Featured article, which represents some of the best content on English Wikipedia.
![]() An H II region or HII region is a region of interstellar atomic hydrogen that is ionized. It is typically in a molecular cloud of partially ionized gas in which star formation has recently taken place, with a size ranging from one to hundreds of light years, and density from a few to about a million particles per cubic centimetre. The Orion Nebula, now known to be an H II region, was observed in 1610 by Nicolas-Claude Fabri de Peiresc by telescope, the first such object discovered. The regions may be of any shape because the distribution of the stars and gas inside them is irregular. The short-lived blue stars created in these regions emit copious amounts of ultraviolet light that ionize the surrounding gas. H II regions—sometimes several hundred light-years across—are often associated with giant molecular clouds. They often appear clumpy and filamentary, sometimes showing intricate shapes such as the Horsehead Nebula. H II regions may give birth to thousands of stars over a period of several million years. In the end, supernova explosions and strong stellar winds from the most massive stars in the resulting star cluster disperse the gases of the H II region, leaving a cluster of stars which have formed. (Full article...)Did you know -
More Did you know (auto generated)![]()
WikiProjectsSelected image -![]() Abell 2199 is a galaxy cluster in the Abell catalogue featuring a brightest cluster galaxy NGC 6166, a cD galaxy. Abell 2199, located in the Hercules constellation, is the definition of a Bautz-Morgan type I cluster due to NGC 6166. Astronomy News
September anniversaries
Space-related PortalsAstronomical eventsAll times UT unless otherwise specified. Portal:Astronomy/Events/September 2024 TopicsSubcategoriesSelect [►] to view subcategories
Things you can do
Wikibooks![]() These books may be in various stages of development. See also the related Science and Mathematics bookshelves.
WikijuniorAssociated WikimediaThe following Wikimedia Foundation sister projects provide more on this subject:
Discover Wikipedia using portals Shortcuts to this page: Astronomy portal • P:ASTRO Purge server cache |