Portal:Astronomy

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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 - load new batch

The following are images from various astronomy-related articles on Wikipedia.

Image 1Places like Paranal Observatory offer crystal clear skies for observing astronomical objects with or without instruments. (from Amateur astronomy)
Image 2The Hubble Space Telescope (from History of astronomy)
Image 3Map of the Milky Way Galaxy, with the constellations that cross the galactic plane in each direction and the known prominent components annotated including main arms, spurs, bar, nucleus/bulge, notable nebulae and globular clusters (from History of astronomy)
Image 4History of the Universe – gravitational waves are hypothesized to arise from cosmic inflation, a rapidly accelerated expansion just after the Big Bang (from Physical cosmology)
Image 5The Oort cloud, one of the most successful theoretical model about the Solar System (from Theoretical astronomy)
Image 6An assembly in Estonia to observe meteors (from Observational astronomy)
Image 7The Northern Hemisphere page from Johann Bayer's 1661 edition of Uranometria - the first atlas to have star charts covering the entire celestial sphere (from History of astronomy)
Image 8ALMA is the world's most powerful telescope for studying the Universe at submillimeter and millimeter wavelengths. (from Observational astronomy)
Image 9An image of the Cat's Paw Nebula created combining the work of professional and amateur astronomers. The image is the combination of the 2.2-metre MPG/ESO telescope of the La Silla Observatory in Chile and a 0.4-meter amateur telescope. (from Amateur astronomy)
Image 10Babylonian tablet in the British Museum recording Halley's comet in 164 BC (from History of astronomy)
Image 11Artist conception of the Big Bang cosmological model, the most widely accepted out of all in physical cosmology (neither time nor size to scale) (from Physical cosmology)
Image 12The Nebra sky disk, Germany, 1800 - 1600 BC (from History of astronomy)
Image 13Portrait of the Flemish astronomer Ferdinand Verbiest who became Head of the Mathematical Board and Director of the Observatory of the Chinese emperor in 1669 (from Astronomer)
Image 14Sunset at the equinox from the prehistoric site of Pizzo Vento at Fondachelli Fantina, Sicily (from History of astronomy)
Image 15Historical accuracy of atomic clocks from NIST. (from Theoretical astronomy)
Image 169th-century diagram of the positions of the seven planets on 18 March 816, from the Leiden Aratea (from History of astronomy)
Image 17The main platform at La Silla hosts a huge range of telescopes with which astronomers can explore the Universe. (from Observational astronomy)
Image 18Calendrical functions of the Berlin Gold Hat c. 1000 BC (from History of astronomy)
Image 19Sir Patrick Moore was one of the world's leading popularisers of astronomy. (from Amateur astronomy)
Image 20Ultra HD photography taken at La Silla Observatory (from Observational astronomy)
Image 21An amateur astrophotography setup with an automated guide system connected to a laptop (from Observational astronomy)
Image 22Amateur astronomer recording observations of the sun. (from Amateur astronomy)
Image 23Southern Hemisphere (from History of astronomy)
Image 24Overview of types of observational astronomy by observed wavelengths and their observability. (from Observational astronomy)
Image 25One of the Oldest Observatories in South America is the Quito Astronomical Observatory, founded in 1873 and located 12 minutes south of the Equator in Quito, Ecuador. The Quito Astronomical Observatory is the National Observatory of Ecuador and is located in the Historic Center of Quito and is managed by the National Polytechnic School. (from Observational astronomy)
Image 26The Crab Nebula as seen in various wavelengths (from Observational astronomy)
Image 27Mayall telescope at Kitt Peak National Observatory (from Observational astronomy)
Image 28Amateur astronomy groups are often involved in outreach in order to introduce astronomy to the general public (from Amateur astronomy)
Image 29The Antikythera Mechanism was an analog computer from 150 to 100 BC designed to calculate the positions of astronomical objects. (from History of astronomy)
Image 30Comparison of CMB (Cosmic microwave background) results from satellites COBE, WMAP and Planck documenting a progress in 1989–2013 (from History of astronomy)
Image 31Arabic astrolabe from 1079 to 1080 AD (from History of astronomy)
Image 32Historical Jantar Mantar observatory in Jaipur, India (from History of astronomy)
Image 33A voting session is conducted in 2006 International Astronomical Union's general assembly for determining a new definition of a planet (from Astronomer)
$Image 3450 cm refracting telescope at Nice Observatory (from Observational astronomy)$

Image 3450 cm refracting telescope at Nice Observatory (from Observational astronomy)
Image 35Segment of the astronomical ceiling of Senenmut's Tomb (circa 1479–1458 BCE), depicting constellations, protective deities, and twenty-four segmented wheels for the hours of the day and the months of the year (from History of astronomy)
Image 36"El Caracol" observatory temple at Chichen Itza, Mexico (from History of astronomy)

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Featured article - show another

This is a Featured article, which represents some of the best content on English Wikipedia.

SN 1994D (bright spot on the lower left), a type Ia supernova within its host galaxy, NGC 4526

A supernova (pl.: supernovae or supernovas) is a powerful and luminous explosion of a star. A supernova occurs during the last evolutionary stages of a massive star, or when a white dwarf is triggered into runaway nuclear fusion. The original object, called the progenitor, either collapses to a neutron star or black hole, or is completely destroyed to form a diffuse nebula. The peak optical luminosity of a supernova can be comparable to that of an entire galaxy before fading over several weeks or months.

The last supernova directly observed in the Milky Way was Kepler's Supernova in 1604, appearing not long after Tycho's Supernova in 1572, both of which were visible to the naked eye. The remnants of more recent supernovae have been found, and observations of supernovae in other galaxies suggest they occur in the Milky Way on average about three times every century. A supernova in the Milky Way would almost certainly be observable through modern astronomical telescopes. The most recent naked-eye supernova was SN 1987A, which was the explosion of a blue supergiant star in the Large Magellanic Cloud, a satellite galaxy of the Milky Way. (Full article...)

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Did you know - show different entries

... that Oscar Monnig donated one of the largest private collections of meteorites to Texas Christian University?
... that at first light in 1987, the William Herschel Telescope was the third largest single optical telescope in the world, and is still the second largest in Europe?
... that a Bok globule is a dark cloud of dense dust and gas, first observed by astronomer Bart Bok in the 1940s, in which star formation is taking place within the H II region?
... that the aerial telescope is a type of very long focal length refracting telescope built in the second half of the 17th century that did not use a tube?
... that the galaxy pair Arp 147 contains a ring of nine black holes?

More Did you know facts

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... that in many works of fiction, the asteroid belt is the remnants of a destroyed planet?
... that Susan Murabana created Africa's first permanent planetarium?
... that it took five years of observations to find the planet orbiting the star HD 175167?
... that fictional depictions of Jupiter have portrayed human habitation on the planet and its moons both by altering the environment to suit humans and altering humans to be suited to the environment?
... that the Passive Seismic Experiment Package recorded one of the first instances of humans littering on another planetary body?
... that the star TRAPPIST-1 has seven planets, several of which may have temperatures that would allow the existence of liquid water (artist's impression depicted)?

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WikiProjects

WikiProject Astronomy	WikiProject Solar System



WikiProject Cosmology	WikiProject Spaceflight

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Credit: NASA/ESA/AURA/Caltech

In astronomy, the Pleiades, or Seven Sisters (Messier object 45), is an open star cluster containing middle-aged hot B-type stars located in the constellation of Taurus. It is among the nearest star clusters to Earth and is the cluster most obvious to the naked eye in the night sky.

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Astronomy News

20 February 2024 –: Astronomers identify the most luminous object ever observed, QSO J0529-4351, a quasar that accretes around one solar mass per day. (The Guardian) (Nature.com)
24 November 2023 –: Astronomers at the Telescope Array Project in Utah, United States, observe the second largest cosmic ray ever detected, the so-called Amaterasu particle, with an energy of 244 EeV. (Cosmos Magazine)

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April anniversaries

2 April 1968 – The epic science fiction film, 2001: A Space Odyssey is released
3 April 2014 – NASA announces that the Cassini orbiter has found evidence of an underground body of water on Enceladus, a moon of Saturn
7 April 2001 – Mars Odyssey orbiter is launched to map and search for water on Mars
12 April 1961 – Cosmonaut Yuri Gagarin becomes the first human to enter outer space when he is launched into orbital flight in Vostok 1
19 April 1971 – The first space station, Salyut 1, is launched into orbit
24 April 1990 – The Hubble Space Telescope, a powerful research tool and public relations boon for astronomy, is launched into orbit

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Space-related Portals

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Astronomical events

All times UT unless otherwise specified.

6 April, 09:25	Moon occults Saturn
7 April, 08:11	Moon occults Neptune
7 April, 16:47	Moon occults Venus
7 April, 17:53	Moon at perigee
8 April, 18:18	New moon and Total Solar Eclipse
11 April, 22:53	Mercury at inferior conjunction
20 April, 02:09	Moon at apogee
22 April, 06:44	Lyrids peak
23 April, 23:49	Full moon