HOME
*





Astronomical Catalogue
An astronomical catalog or catalogue is a list or tabulation of astronomical objects, typically grouped together because they share a common type, morphology, origin, means of detection, or method of discovery. The oldest and largest are star catalogues. Hundreds have been published, including general ones and special ones for such items as infrared stars, variable stars, giant stars, multiple star systems, star clusters, and so forth. General catalogs for deep space objects or for objects other than stars are also large. Again, there are specialized ones for nebulas, galaxies, X-ray sources, radio sources, quasars and other classes. The same is true for asteroids, comets and other Small Solar System body, solar system bodies. Astronomical catalogs such as those for asteroids may be compiled from multiple sources, but most modern catalogs are the result of a particular astronomical survey of some kind. Since the late 20th century catalogs are increasingly often compiled by com ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Screenshot Of The ESO Archive Science Portal
screenshot (also known as screen capture or screen grab) is a digital image that shows the contents of a computer display. A screenshot is created by the operating system or software running on the device powering the display. Additionally, screenshots can be captured by an external camera, using photography to capture contents on the screen. Screenshot techniques Digital techniques The first screenshots were created with the first interactive computers around 1960. Through the 1980s, computer operating systems did not universally have built-in functionality for capturing screenshots. Sometimes text-only screens could be dumped to a text file, but the result would only capture the content of the screen, not the appearance, nor were graphics screens preservable this way. Some systems had a BSAVE command that could be used to capture the area of memory where screen data was stored, but this required access to a BASIC prompt. Systems with composite video output could be conn ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Small Solar System Body
A small Solar System body (SSSB) is an object in the Solar System that is neither a planet, a dwarf planet, nor a natural satellite. The term was first defined in 2006 by the International Astronomical Union (IAU) as follows: "All other objects, except satellites, orbiting the Sun shall be referred to collectively as 'Small Solar System Bodies' ".''RESOLUTION B5 - Definition of a Planet in the Solar System''
(IAU) This encompasses all s and all s other than those that are

picture info

Magnitude (astronomy)
In astronomy, magnitude is a unitless measure of the brightness Brightness is an attribute of visual perception in which a source appears to be radiating or reflecting light. In other words, brightness is the perception elicited by the luminance of a visual target. The perception is not linear to luminance, ... of an astronomical object, object in a defined passband, often in the visible spectrum, visible or infrared spectrum, but sometimes across all wavelengths. An imprecise but systematic determination of the magnitude of objects was introduced in ancient times by Hipparchus. The scale is Logarithmic scale, logarithmic and defined such that a magnitude 1 star is exactly 100 times brighter than a magnitude 6 star. Thus each step of one magnitude is \sqrt[5] \approx 2.512 times brighter than the magnitude 1 higher. The brighter an object appears, the lower the value of its magnitude, with the brightest objects reaching negative values. Astronomers use two different defini ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Tycho Brahe
Tycho Brahe ( ; born Tyge Ottesen Brahe; generally called Tycho (14 December 154624 October 1601) was a Danish astronomer, known for his comprehensive astronomical observations, generally considered to be the most accurate of his time. He was known during his lifetime as an astronomer, astrologer, and alchemist. He was the last major astronomer before the invention of the telescope. An heir to several noble families, Tycho was well-educated. He took an interest in astronomy and in the creation of more accurate instruments of measurement. He worked to combine what he saw as the geometrical benefits of Copernican heliocentrism with the philosophical benefits of the Ptolemaic system, and devised the Tychonic system, his own version of a model of the universe, with the Sun orbiting the Earth, and the planets as orbiting the Sun. In ''De nova stella'' (1573), he refuted the Aristotelian belief in an unchanging celestial realm. His measurements indicated that "new stars" (''stellae ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Large Magellanic Cloud
The Large Magellanic Cloud (LMC), or Nubecula Major, is a satellite galaxy of the Milky Way. At a distance of around 50 kiloparsecs (≈160,000  light-years), the LMC is the second- or third-closest galaxy to the Milky Way, after the Sagittarius Dwarf Spheroidal (16 kpc) and the possible dwarf irregular galaxy known as the Canis Major Overdensity. Based on the D25 isophote at the B-band (445 nm wavelength of light), the Large Magellanic Cloud is approximately across. It is roughly a hundredth as massive as the Milky WayMagellanic Cloud
. ''''. 2009. Encyclopædia Britannica Online. 30 Aug. 2009.
and is the fourth-largest g ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Andromeda Galaxy
The Andromeda Galaxy (IPA: ), also known as Messier 31, M31, or NGC 224 and originally the Andromeda Nebula, is a barred spiral galaxy with the diameter of about approximately from Earth and the nearest large galaxy to the Milky Way. The galaxy's name stems from the area of Earth's sky in which it appears, the constellation of Andromeda, which itself is named after the princess who was the wife of Perseus in Greek mythology. The virial mass of the Andromeda Galaxy is of the same order of magnitude as that of the Milky Way, at . The mass of either galaxy is difficult to estimate with any accuracy, but it was long thought that the Andromeda Galaxy is more massive than the Milky Way by a margin of some 25% to 50%. This has been called into question by a 2018 study that cited a lower estimate on the mass of the Andromeda Galaxy, combined with preliminary reports on a 2019 study estimating a higher mass of the Milky Way. The Andromeda Galaxy has a diameter of about , making it the ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Book Of Fixed Stars
The ''Book of Fixed Stars'' ( ar, كتاب صور الكواكب ', literally ''The Book of the Shapes of Stars'') is an astronomical text written by Abd al-Rahman al-Sufi (Azophi) around 964. Following the translation movement in the 9th century AD, the book was written in Arabic, the common language for scholars across the vast Islamic territories, although the author himself was Persian. It was an attempt to create a synthesis of the comprehensive star catalogue in Ptolemy’s ''Almagest'' (books VII and VIII) with the indigenous Arabic astronomical traditions on the constellations (notably the Bedouin constellation system of the ''Anwā’''). The original manuscript no longer survives as an autograph, however, the importance of tradition and the practice of diligence central to Islamic manuscript tradition have ensured the survival of the ''Book of Stars'' in later-made copies. Historical context The treatise was written in the Persian city of Shiraz, for the patron and ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Abd Al-Rahman Al-Sufi
ʿAbd al-Rahman al-Sufi ( fa, عبدالرحمن صوفی; December 7, 903 – May 25, 986) was an iranianRobert Harry van Gent. Biography of al-Sūfī'. "The Persian astronomer Abū al-Husayn ‘Abd al-Rahmān ibn ‘Umar al-Sūfī was born in Rayy (near Tehrān) on 7 December 903 4 Muharram 291 Hand died in Baghdād on 25 May 986 3 Muharram 376 H... the Persian astronomer Abū al-Husayn ‘Abd al-Rahmān ibn ‘Umar al-Sūfī who was commonly known by European astronomers as Azophi Arabus". University of Utrecht, Netherlands. Retrieved January 11, 2014 astronomer also known as ʿAbd ar-Rahman as-Sufi, ʿAbd al-Rahman Abu al-Husayn, ʿAbdul Rahman Sufi, or ʿAbdurrahman Sufi and, historically, in the West as Azophi, Azophi Arabus, and Albuhassin. Al-Sufi published his famous ''Book of Fixed Stars'' in 964, which included both textual descriptions and pictures. Al-Biruni reports that his work on the ecliptic was carried out in Shiraz. He lived at the Buyid court in Isfahan. B ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Astronomy
Astronomy () is a natural science that studies astronomical object, celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and chronology of the Universe, evolution. Objects of interest include planets, natural satellite, moons, stars, nebulae, galaxy, 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 atmosphere of Earth, 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 Babylonian astronomy, Babylonians, Greek astronomy, Greeks, Indian astronomy, Indians, Egyptian astronomy, Egyptians, Chinese astronomy, Chinese, Maya civilization, Maya, and many anc ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Ecliptic
The ecliptic or ecliptic plane is the orbital plane of the Earth around the Sun. From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic against the background of stars. The ecliptic is an important reference plane and is the basis of the ecliptic coordinate system. Sun's apparent motion The ecliptic is the apparent path of the Sun throughout the course of a year. Because Earth takes one year to orbit the Sun, the apparent position of the Sun takes one year to make a complete circuit of the ecliptic. With slightly more than 365 days in one year, the Sun moves a little less than 1° eastward every day. This small difference in the Sun's position against the stars causes any particular spot on Earth's surface to catch up with (and stand directly north or south of) the Sun about four minutes later each day than it would if Earth did not orbit; a day on Earth is therefore 24 hours ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the earliest constellations likely go back to prehistory. People used them to relate stories of their beliefs, experiences, creation myth, creation, or mythology. Different cultures and countries adopted their own constellations, some of which lasted into the early 20th century before today's constellations were internationally recognized. The recognition of constellations has changed significantly over time. Many changed in size or shape. Some became popular, only to drop into obscurity. Some were limited to a single culture or nation. The 48 traditional Western constellations are Greek. They are given in Aratus' work ''Phenomena'' and Ptolemy's ''Almagest'', though their origin probably predates these works by several centuries. Constellation ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Star
A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night sky, night, but their immense distances from Earth make them appear as fixed stars, fixed points of light. The most prominent stars have been categorised into constellations and asterism (astronomy), asterisms, and many of the brightest stars have proper names. Astronomers have assembled star catalogues that identify the known stars and provide standardized stellar designations. The observable universe contains an estimated to stars. Only about 4,000 of these stars are visible to the naked eye, all within the Milky Way galaxy. A star's life star formation, begins with the gravitational collapse of a gaseous nebula of material composed primarily of hydrogen, along with helium and trace amounts of heavier elements. Its stellar ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]