Portal:Astronomy

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The Astronomy Portal

Introduction

Astronomy (from Greek: ἀστρονομία, literally meaning the science that studies the laws of the stars) is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, galaxies, 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 Babylonians, Greeks, Indians, Egyptians, 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. Nowadays, professional astronomy is often said to be the same as astrophysics.

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 2Ultra HD photography taken at La Silla Observatory. (from Observational 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 4Mayall telescope at Kitt Peak National Observatory (from Observational astronomy)
Image 5Calendrical functions of the Berlin Gold Hat c. 1000 BC (from History of astronomy)
Image 6"El Caracol" observatory temple at Chichen Itza, Mexico. (from History of astronomy)
Image 7Telescope set up in Brooklyn Bridge Park for a public stargazing session (from Amateur astronomy)
Image 8The Astronomer, 1668, by Johannes Vermeer (from Astronomer)
Image 9The Crab Nebula as seen in various wavelengths (from Observational astronomy)
Image 10An assembly in Estonia to observe meteors (from Observational astronomy)
Image 11The main platform at La Silla hosts a huge range of telescopes with which astronomers can explore the Universe. (from Observational astronomy)
Image 12Sir Patrick Moore was one of the world's leading popularisers of astronomy. (from Amateur astronomy)
Image 13History of the Universe – gravitational waves are hypothesized to arise from cosmic inflation, a faster-than-light expansion just after the Big Bang (from Physical cosmology)
Image 14The Antikythera Mechanism was an analog computer from 150–100 BC designed to calculate the positions of astronomical objects. (from History of astronomy)
Image 1550 cm refracting telescope at Nice Observatory. (from Observational astronomy)
Image 16An amateur astrophotography setup with an automated guide system connected to a laptop. (from Observational astronomy)
Image 17The Nebra sky disk Germany 1600 BC (from History of astronomy)
Image 18Arabic astrolabe from 1208 AD (from History of astronomy)
Image 19Comparison of CMB (Cosmic microwave background) results from satellites COBE, WMAP and Planck documenting a progress in 1989–2013. (from History of astronomy)
Image 20Historical accuracy of atomic clocks from NIST. (from Theoretical 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 22Sunset at the equinox from the prehistoric site of Pizzo Vento at Fondachelli Fantina, Sicily (from History of astronomy)
Image 23Segment 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 249th-century diagram of the positions of the seven planets on 18 March 816, from the Leiden Aratea. (from History of 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 26Hubble Space Telescope. (from History of astronomy)
Image 27Historical Jantar Mantar observatory in Jaipur, India. (from History of astronomy)
Image 28Babylonian tablet in the British Museum recording Halley's comet in 164 BC. (from History of astronomy)
Image 29ALMA is the world's most powerful telescope for studying the Universe at submillimeter and millimeter wavelengths. (from Observational astronomy)

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

Andromeda is one of the 48 constellations listed by the 2nd-century Greco-Roman astronomer Ptolemy, and one of the 88 modern constellations. Located north of the celestial equator, it is named for Andromeda, daughter of Cassiopeia, in the Greek myth, who was chained to a rock to be eaten by the sea monster Cetus. Andromeda is most prominent during autumn evenings in the Northern Hemisphere, along with several other constellations named for characters in the Perseus myth. Because of its northern declination, Andromeda is visible only north of 40° south latitude; for observers farther south, it lies below the horizon. It is one of the largest constellations, with an area of 722 square degrees. This is over 1,400 times the size of the full moon, 55% of the size of the largest constellation, Hydra, and over 10 times the size of the smallest constellation, Crux.

Its brightest star, Alpha Andromedae, is a binary star that has also been counted as a part of Pegasus, while Gamma Andromedae is a colorful binary and a popular target for amateur astronomers. Only marginally dimmer than Alpha, Beta Andromedae is a red giant, its color visible to the naked eye. The constellation's most obvious deep-sky object is the naked-eye Andromeda Galaxy (M31, also called the Great Galaxy of Andromeda), the closest spiral galaxy to the Milky Way and one of the brightest Messier objects. Several fainter galaxies, including M31's companions M110 and M32, as well as the more distant NGC 891, lie within Andromeda. The Blue Snowball Nebula, a planetary nebula, is visible in a telescope as a blue circular object. (Full article...)

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Did you know - show different entries

... that light echoes appear to exceed the speed of light due to simple interstellar illusions?
... that the Leo IV dwarf galaxy is one of the smallest satellites of the Milky Way?
... that a hydrocarbon lake on Saturn's moon Titan and an active volcano on Jupiter's moon Io are among the Solar System features named after deities from Māori mythology?
... that the Local Void is an empty region of space, devoid of matter, lying adjacent to our own Milky Way galaxy?
... that William Herschel's 40-foot telescope was the largest telescope in the world for 50 years?

More Did you know facts

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... that Nandivada Rathnasree, who ran Delhi's planetarium, proposed that astronomers could be taught using India's stone-built observatories?
... that pushbacks of migrants in the Aegean Sea have been described as "a human rights violation that encapsulates a will to eliminate a person's presence on the face of the planet"?
... that the spiral galaxy NGC 3393 hosts the nearest known pair of supermassive black holes?
... that NGC 4848, a spiral galaxy, lost most of its hydrogen gas as it passed through the Coma Cluster due to ram pressure?
... that Mariner 1, the United States' first interplanetary probe, was lost in 1962 due to the miscoding of a single character in its software?
... that the producers of The Jet Propelled Couch hired "Miss Color TV", Vampira, and several Miss Americas to portray attractive creatures inhabiting an imaginary planet?

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WikiProjects

WikiProject Astronomy	WikiProject Solar System



WikiProject Cosmology	WikiProject Spaceflight

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Credit: NASA

SS 433 is an eclipsing X-ray binary system, with the primary most likely a black hole, or possibly a neutron star. Image is an artist's impression of SS 433.

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Astronomy News

12 October 2021 – Discoveries of exoplanets: NASA astronomers announce the discovery of TIC 257060897b, a Hot Jupiter exoplanet that is 50% larger and 30% less massive than Jupiter. The discovery was made using the Transiting Exoplanet Survey Satellite. (Science Times)

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February anniversaries

5 February 1974 – Mariner 10 becomes the first spacecraft to use a gravity assist when it flies by Venus in order to reach Mercury
5 February 2002 – HESSI (High Energy Solar Spectroscopic Imager) solar flare observatory is launched on a mission to explore the physics of particle acceleration and energy release in solar flares
10 February 2002 – Solar Orbiter is launched to perform detailed measurements of the inner heliosphere and nascent solar wind, and perform close observations of the polar regions of the Sun
15 February 1845 – The Leviathan of Parsonstown, the world's largest telescope from 1845 to 1917, sees first light
18 February 1930 – 23-year-old astronomer Clyde Tombaugh discovers Pluto by using a blink comparator on photographs he took in the previous month at Lowell Observatory
25 February 2002 – Mariner 6 is launched to study the surface and atmosphere of Mars during close flybys

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Space-related Portals

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Astronomical events

All times UT unless otherwise specified.

1 February, 05:46	New moon
4 February, 18:34	Saturn at conjunction
7 February, 19:39	Moon occults Uranus
11 February, 02:39	Moon at apogee
16 February, 16:57	Full moon
16 February, 20:59	Mercury at greatest western elongation
26 February, 22:18	Moon at perigee