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 - load new batch

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

Image 1The Oort cloud, one of the most successful theoretical models about the Solar System (from Theoretical astronomy)
Image 2Comparison of CMB (Cosmic microwave background) results from satellites COBE, WMAP and Planck documenting a progress in 1989–2013 (from History of astronomy)
Image 3Portrait 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 4One 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 5Arabic astrolabe from 1079 to 1080 AD (from History of astronomy)
Image 6Amateur astronomer recording observations of the sun. (from Amateur astronomy)
Image 7The Crab Nebula as seen in various wavelengths (from Observational astronomy)
Image 8The 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 9History 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 10Babylonian tablet in the British Museum recording Halley's Comet in 164 BC (from History of astronomy)
Image 11Segment of the astronomical ceiling of Senenmut's Tomb (circa 1479–1458 BC), 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 12Ultra HD photography taken at La Silla Observatory (from Observational astronomy)
Image 13The main platform at La Silla hosts a huge range of telescopes with which astronomers can explore the Universe. (from Observational astronomy)
Image 14The Antikythera Mechanism was an analog computer from 150 to 100 BC designed to calculate the positions of astronomical objects. (from History of astronomy)
Image 15Map 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 16Mayall telescope at Kitt Peak National Observatory (from Observational astronomy)
Image 17An example of a gravitational lens found in the DESI Legacy Surveys data. There are four sets of lensed images in DESI-090.9854-35.9683, corresponding to four distinct background galaxies—from the outermost giant red arc to the innermost bright blue arc, arranged in four concentric circles. All of them are gravitationally warped—or lensed—by the orange galaxy at the very center. Dark matter is expected to produce gravitational lensing also. (from Physical cosmology)
Image 18Overview of types of observational astronomy by observed wavelengths and their observability. (from Observational astronomy)
Image 19Calendrical functions of the Berlin Gold Hat c. 1000 BC (from History of astronomy)
Image 20ALMA is the world's most powerful telescope for studying the Universe at submillimeter and millimeter wavelengths. (from Observational astronomy)
Image 21An 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 22The Nebra sky disk, Germany, 1800–1600 BC (from History of astronomy)
Image 23An amateur astrophotography setup with an automated guide system connected to a laptop (from Observational astronomy)
Image 24Amateur astronomy groups are often involved in outreach to introduce astronomy to the general public (from Amateur astronomy)
Image 25The Hubble Space Telescope (from History of astronomy)
Image 26Artist 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 27The inflationary theory as an augmentation to the Big Bang theory was first proposed by Alan Guth of MIT. Inflation solves the 'horizon problem' by making the early universe much more compact than was assumed in the standard model. Given such smaller size, causal contact (i.e., thermal communication) would have been possible among all regions of the early universe. The image was an adaptation from various generic charts depicting the growth of the size of the observable universe, for both the standard model and inflationary model respectively, of the Big Bang theory. (from Physical cosmology)
Image 28Places like Paranal Observatory offer crystal clear skies for observing astronomical objects with or without instruments. (from Amateur astronomy)
Image 29Historical Jantar Mantar observatory in Jaipur, India (from History of astronomy)
Image 30Sunset at the equinox from the prehistoric site of Pizzo Vento at Fondachelli Fantina, Sicily (from History of astronomy)
$Image 3150 cm refracting telescope at Nice Observatory (from Observational astronomy)$

Image 3150 cm refracting telescope at Nice Observatory (from Observational astronomy)
Image 32Sir Patrick Moore was one of the world's leading popularisers of astronomy. (from Amateur astronomy)
Image 33"El Caracol" observatory temple at Chichen Itza, Mexico (from History of astronomy)
Image 34Southern Hemisphere (from History of astronomy)
Image 35Historical accuracy of atomic clocks from NIST. (from Theoretical astronomy)
Image 369th-century diagram of the positions of the seven planets on 18 March 816, from the Leiden Aratea (from History of astronomy)
Image 37An assembly in Estonia to observe meteors (from Observational astronomy)
Image 38A voting session is conducted in 2006 International Astronomical Union's general assembly for determining a new definition of a planet (from Astronomer)

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

Image of Barnard's Star and its surroundings, c. 2006 (south is up)

Barnard's Star is a small red dwarf star in the constellation of Ophiuchus. At a distance of 5.96 light-years (1.83 pc) from Earth, it is the fourth-nearest-known individual star to the Sun after the three components of the Alpha Centauri system, and is the closest star in the northern celestial hemisphere. Its stellar mass is about 16% of the Sun's, and it has 19% of the Sun's diameter. Despite its proximity, the star has a dim apparent visual magnitude of +9.5 and is invisible to the unaided eye; it is much brighter in the infrared than in visible light.

Barnard's Star is among the most studied red dwarfs because of its proximity and favorable location for observation near the celestial equator. Historically, research on Barnard's Star has focused on measuring its stellar characteristics, its astrometry, and also refining the limits of possible extrasolar planets. Although Barnard's Star is ancient, it still experiences stellar flare events, one being observed in 1998. (Full article...)

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Did you know - show different entries

... that Abell 2142, a galaxy cluster, is one of the most massive objects in the universe?
... that a jet from one of the component stars of Z Canis Majoris is over 11 light-years long?
... that Messier 58 is one of the brightest galaxies in the Virgo Cluster and is 1 of 4 barred spiral galaxies included in Charles Messier's catalog?
... that the asteroid 2014 AA entered Earth's atmosphere on the early morning of January 2, 2014, less than a day after it was discovered?
... that ATIC, a balloon-borne detector flying over Antarctica, recently found excess cosmic ray electrons that might provide evidence for dark matter consisting of Kaluza-Klein particles?
.... that the Sun fuses about 620 million metric tons of hydrogen per seconds due to Gravity?

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... that the Passive Seismic Experiment Package recorded one of the first instances of humans littering on another planetary body?
... that the majority of extrasolar planets in fiction are inhabited by native species?
... that a group of K-pop fans performed a dance with the goal of convincing a company to commit to 100% renewable energy?
... that 1ES 1927+654, a galaxy in Draco, exhibited such extreme nuclear activity that it challenged conventional models of black-hole environments?
... that the galaxy NGC 1700 has a rotating hot gas disk glowing in X-rays after merging with another galaxy three billion years ago?
... that Kim Ye-ji's performance in the 10 meter air pistol at the 2024 Summer Olympics led her to be dubbed the "coolest person on the planet"?

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WikiProjects

WikiProject Astronomy	WikiProject Solar System



WikiProject Cosmology	WikiProject Spaceflight

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Credit: NASA Earth Observatory / STEREO Science Center

A coronal mass ejection (CME) is a significant release of plasma and accompanying magnetic field from the solar corona. They often follow solar flares and are normally present during a solar prominence eruption. Coronal mass ejections release large quantities of matter and electromagnetic radiation into space above the Sun's surface, either near the corona, or farther into the planetary system, or beyond (interplanetary CME).

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Astronomy News

21 November 2024 –: The European Southern Observatory announces that its astronomers in Chile capture the first close-up image of a star outside the Milky Way. (The New York Times)
20 November 2024 – Discoveries of exoplanets: In a study published by the Nature journal, astronomers announce the discovery of IRAS 04125+2902 b, a newborn exoplanet. The discovery was made by Madyson Barber, a graduate student at the University of North Carolina at Chapel Hill. (Nature) (ABC News)

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May anniversaries

1 May 1959 – The former Beltsville Center is renamed to Goddard Space Flight Center in honor of Dr. Robert H. Goddard, rocket pioneer who achieved first launch of a liquid-fueled rocket
4 May 1967 – Lunar Orbiter 4 is launched to perform a photographic survey of lunar surface features
7 May 1975 – Explorer 53 (SAS-C), a NASA X-ray astronomy space telescope, is launched from the San Marco Range in Kenya, Africa
7 May 1997 – English-language French science fiction action film, The Fifth Element is released showing passenger inter-constellation vehicles, spacefighter craft, and various non-human creatures
14 May 1935 – The planetarium at Griffith Observatory in Los Angeles, California opens
14 May 1973 – The first American space station, Skylab, is launched
18 May 1969 – The Apollo 10 human spaceflight is launched, testing all aspects of the lunar landing mission, except the actual lunar landing
20 May 1978 – Pioneer Venus is launched from Cape Canaveral, Florida becoming the first spacecraft placed in orbit around Venus
30 May 1971 – Mariner 9 robotic space probe is launched becoming the first spacecraft to orbit Mars

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Space-related Portals

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Astronomical events

All times UT unless otherwise specified.

5 May, 02:07	Eta Aquariids peak
11 May, 00:49	Moon at apogee
12 May, 16:56	Full moon
18 May, 00:55	Uranus at conjunction
26 May, 01:37	Moon at perigee
27 May, 03:02	New moon
30 May, 04:07	Mercury at superior conjunction