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Zhúlóng (galaxy)
Zhúlóng is an extremely massive grand-design spiral galaxy located at a redshift distance of z=5.2 (12.8 Gly) in the constellation of Sextans. It is believed to be the most distant known grand design spiral galaxy. Spiral galaxies beyond red shift 3.0 are generally rare with only a few known. The galaxy has well-defined spiral arms that have dense star formation regions while the core is quiescent. However the rate of star formation is low forming 66 solar masses of stars per year. The size of this galaxy is comparable to the Milky Way galaxy, being an estimated 62,000 light years in diameter. It has a mass of around 100 billion solar masses. Naming The galaxy was named Zhúlóng meaning “Torch Dragon” in Chinese mythology. In the myth, Zhúlóng is a powerful red solar dragon that creates day and night by opening and closing its eyes, symbolizing light and cosmic time. Discovery Zhúlóng was discovered by a team led by Mengyuan Xiao, and announced in a paper s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Webb Space Telescope
The James Webb Space Telescope (JWST) is a space telescope designed to conduct infrared astronomy. As the largest telescope in space, it is equipped with high-resolution and high-sensitivity instruments, allowing it to view objects too old, List of the most distant astronomical objects, distant, or faint for the Hubble Space Telescope. This enables investigations across many fields of astronomy and cosmology, such as observation of the Population III star, first stars and the Galaxy formation and evolution, formation of the first galaxies, and detailed atmospheric characterization of potentially habitable exoplanets. Although the Webb's mirror diameter is 2.7 times larger than that of the Hubble Space Telescope, it produces images of comparable optical resolution, resolution because it observes in the longer-wavelength infrared spectrum. The longer the wavelength of the spectrum, the larger the information-gathering surface required (mirrors in the infrared spectrum or antenna a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
J2000
In astronomy, an epoch or reference epoch is a moment in time used as a reference point for some time-varying astronomical quantity. It is useful for the celestial coordinates or orbital elements of a celestial body, as they are subject to perturbations and vary with time. These time-varying astronomical quantities might include, for example, the mean longitude or mean anomaly of a body, the node of its orbit relative to a reference plane, the direction of the apogee or aphelion of its orbit, or the size of the major axis of its orbit. The main use of astronomical quantities specified in this way is to calculate other relevant parameters of motion, in order to predict future positions and velocities. The applied tools of the disciplines of celestial mechanics or its subfield orbital mechanics (for predicting orbital paths and positions for bodies in motion under the gravitational effects of other bodies) can be used to generate an ephemeris, a table of values giving ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sextans
Sextans is a faint, minor constellation on the celestial equator which was introduced in 1687 by Polish astronomer Johannes Hevelius. Its name is Latin for the astronomical sextant, an instrument that Hevelius made frequent use of in his observations. Characteristics Sextans is a medium sized constellation bordering Leo to the north, touching on Hydra to the southwest, and Crater to the southeast. The recommended three-letter abbreviation for the constellation, as adopted by the International Astronomical Union in 1922, is "Sex". The official constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a square. In the equatorial coordinate system, the right ascension coordinates of these borders lie between and , while the declination coordinates are between +6.43° and −11.7°. Since it is close to the ecliptic plane, the Moon and planets regularly cross the constellation, especially its northeastern corner. Notable features St ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light Travel Distance
Distance measures are used in physical cosmology to generalize the concept of distance between two objects or events in an expanding universe. They may be used to tie some ''observable'' quantity (such as the luminosity of a distant quasar, the redshift of a distant galaxy, or the angular size of the acoustic peaks in the cosmic microwave background (CMB) power spectrum) to another quantity that is not ''directly'' observable, but is more convenient for calculations (such as the comoving coordinates of the quasar, galaxy, etc.). The distance measures discussed here all reduce to the common notion of Euclidean distance at low redshift. In accord with our present understanding of cosmology, these measures are calculated within the context of general relativity, where the Friedmann–Lemaître–Robertson–Walker solution is used to describe the universe. Overview There are a few different definitions of "distance" in cosmology which are all asymptotic one to another for small ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grand Design Spiral Galaxy
A grand design spiral galaxy is a spiral galaxy with prominent and well-defined continuous spiral arms, as opposed to multi-arm, patchy and flocculent spirals which have subtler structural features. The spiral arms of a grand design galaxy extend clearly around the galaxy, covering a significant portion of the galaxy's circumference. Theses spiral arms host lot of star formation making them home to an abundance of bright, hot and short lived massive stars. As of 2002, approximately 10 percent of all currently known spiral galaxies are classified as grand design type spirals, including M51 (Whirlpool Galaxy), M74 (Phantom Galaxy), M81 (Bode’s Galaxy), M83 (Southern pinwheel galaxy), M101 (Pinwheel Galaxy), NGC 6946 (Firworks Galaxy) and IC 342 (The Hidden Galaxy). Origin of structure Density wave theory is the preferred explanation for the well-defined structure of grand design spirals, first suggested by Chia-Chiao Lin and Frank Shu in 1964. The term "grand design" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 first constellations were likely defined in prehistory. People used them to relate stories of their beliefs, experiences, creation myth, creation, and mythology. Different cultures and countries invented 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. Naming constellations also helped astronomers and navigators identify stars more easily. Twelve (or thirteen) ancient constellations belong to the zodiac (straddling the ecliptic, which the Sun, Moon, and planets all traver ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spiral Arm
Spiral arms are a defining feature of spiral galaxies. They manifest as spiral-shaped regions of enhanced brightness within the galactic disc. Typically, spiral galaxies exhibit two or more spiral arms. The collective configuration of these arms is referred to as the spiral pattern or spiral structure of the galaxy. The appearance of spiral sleeves is quite diverse. Grand design spiral galaxy, Grand design spiral galaxies exhibit a symmetrical and distinct pattern, comprising two spiral arms that extend throughout the galaxy. In contrast, the spiral structure of flocculent galaxies comprises numerous small fragments of arms that are not connected to each other. The appearance of spiral arms varies across the electromagnetic spectrum. In addition to increased brightness, spiral arms are characterised by an increased concentration of interstellar medium, interstellar gas and dust, bright stars and star clusters, active starburst region, starburst, a bluer colour, and an enhanced mag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Star Formation
Star formation is the process by which dense regions within molecular clouds in interstellar space—sometimes referred to as "stellar nurseries" or "star-forming regions"—Jeans instability, collapse and form stars. As a branch of astronomy, star formation includes the study of the interstellar medium (ISM) and giant molecular clouds (GMC) as precursors to the star formation process, and the study of protostars and young stellar objects as its immediate products. It is closely related to planet formation, another branch of astronomy. Star formation theory, as well as accounting for the formation of a single star, must also account for the statistics of binary stars and the initial mass function. Most stars do not form in isolation but as part of a group of stars referred as star clusters or stellar associations. First stars Star formation is divided into three groups called "Populations". Population III stars formed from primordial hydrogen after the Big Bang. These stars are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milky Way
The Milky Way or Milky Way Galaxy is the galaxy that includes the Solar System, with the name describing the #Appearance, galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars in other arms of the galaxy, which are so far away that they cannot be individually distinguished by the naked eye. The Milky Way is a barred spiral galaxy with a Galaxy#Isophotal diameter, D25 isophotal diameter estimated at , but only about 1,000 light-years thick at the spiral arms (more at the bulge). Recent simulations suggest that a dark matter area, also containing some visible stars, may extend up to a diameter of almost 2 million light-years (613 kpc). The Milky Way has several List of Milky Way's satellite galaxies, satellite galaxies and is part of the Local Group of galaxies, forming part of the Virgo Supercluster which is itself a component of the Laniakea Supercluster. It is estimated to contain 100–400 billion stars and at least that number of pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chinese Mythology
Chinese mythology () is mythology that has been passed down in oral form or recorded in literature throughout the area now known as Greater China. Chinese mythology encompasses a diverse array of myths derived from regional and cultural traditions. Populated with engaging narratives featuring extraordinary individuals and beings endowed with magical powers, these stories often unfold in fantastical mythological realms or historical epochs. Similar to numerous other mythologies, Chinese mythology has historically been regarded, at least partially, as a factual record of the past. Along with Chinese folklore, Chinese mythology forms an important part of Chinese folk religion and Taoism, especially older popular forms of it. Many narratives recounting characters and events from ancient times exhibit a dual tradition: one that presents a more historicized or euhemerized interpretation, and another that offers a more mythological perspective. Numerous myths delve into the creation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zhulong (mythology)
Zhulong or Zhuyin , also known in English as the , was a giant red solar dragon and god in Chinese mythology. It supposedly had a human's face and snake's body, created day and night by opening and closing its eyes, and created seasonal winds by breathing. Names The key word in the names "Zhuyin" and "Zhulong" is , pronounced ''zhú'' in present-day Mandarin. It describes the act of "shining" or "illuminating" something but, owing to the nature of Chinese grammar, can function as a verb ("to shine", "to illuminate"), an adjective ("shining", "bright"), or a noun ("light", "illumination", an object which illuminates) depending upon its position in a phrase. For example, the Chinese word for "candle" is (''làzhú'') or " wax-''zhú''"; an older word for "lantern" is (''zhúlóng'') or "''zhú''-basket". In the name Zhulong, the ''zhú'' modifies the noun (''lóng'') and thus intends a "shining", "torch-like", or "torch-bearing" Chinese dragon. and others call him "Torch Dr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
