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SN Refsdal
SN Refsdal is the first detected multiply-lensed supernova, visible within the field of the galaxy cluster MACS J1149+2223. It was given its nickname in honor of the Norwegian astrophysicist Sjur Refsdal, who, in 1964, first proposed using time-delayed images from a lensed supernova to study the expansion of the universe. The observations were made using the Hubble Space Telescope. Einstein cross The host galaxy of SN Refsdal is at a redshift of 1.49, corresponding to a comoving distance of 14.4 billion light-years and a lookback time of 9.34 billion years. The multiple images are arranged around the elliptical galaxy at z = 0.54 in a cross-shaped pattern, also known as an " Einstein cross". Reappearance After the discovery of the Refsdal Supernova, astronomers predicted that they would have the rare opportunity to see the supernova again in about one year, after the four images had faded away. This is because the initially observed four-image pattern was only one component ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Past, Present And Future Appearances Of The Refsdal Supernova
''The'' () is a grammatical article in English, denoting persons or things that are already or about to be mentioned, under discussion, implied or otherwise presumed familiar to listeners, readers, or speakers. It is the definite article in English. ''The'' is the most frequently used word in the English language; studies and analyses of texts have found it to account for seven percent of all printed English-language words. It is derived from gendered articles in Old English which combined in Middle English and now has a single form used with nouns of any gender. The word can be used with both singular and plural nouns, and with a noun that starts with any letter. This is different from many other languages, which have different forms of the definite article for different genders or numbers. Pronunciation In most dialects, "the" is pronounced as (with the voiced dental fricative followed by a schwa) when followed by a consonant sound, and as (homophone of the archaic pron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wolfram Alpha
WolframAlpha ( ) is an answer engine developed by Wolfram Research. It answers factual queries by computing answers from externally sourced data. WolframAlpha was released on May 18, 2009 and is based on Wolfram's earlier product Wolfram Mathematica, a technical computing platform. WolframAlpha gathers data from academic and commercial websites such as the CIA's ''The World Factbook'', the United States Geological Survey, a Cornell University Library publication called ''All About Birds'', ''Chambers Biographical Dictionary'', Dow Jones, the ''Catalogue of Life'', CrunchBase, Best Buy, and the FAA to answer queries. A Spanish version was launched in 2022. Technology Overview Users submit queries and computation requests via a text field. WolframAlpha then computes answers and relevant visualizations from a knowledge base of curated, structured data that come from other sites and books. It is able to respond to particularly phrased natural language fact-based questions. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supernovae
A supernova is a powerful and luminous explosion of a star. It has the plural form supernovae or supernovas, and is abbreviated SN or SNe. This transient astronomical event 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. The peak optical luminosity of a supernova can be comparable to that of an entire galaxy before fading over several weeks or months. Supernovae are more energetic than novae. In Latin, ''nova'' means "new", referring astronomically to what appears to be a temporary new bright star. Adding the prefix "super-" distinguishes supernovae from ordinary novae, which are far less luminous. The word ''supernova'' was coined by Walter Baade and Fritz Zwicky in 1929. The last supernova to be directly observed in the Milky Way was Kepler's Supernova in 1604, appearing not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Geographic Society
The National Geographic Society (NGS), headquartered in Washington, D.C., United States, is one of the largest non-profit scientific and educational organizations in the world. Founded in 1888, its interests include geography, archaeology, and natural science, the promotion of environmental and historical conservation, and the study of world culture and history. The National Geographic Society's logo is a yellow portrait frame—rectangular in shape—which appears on the margins surrounding the front covers of its magazines and as its television channel logo. Through National Geographic Partners (a joint venture with The Walt Disney Company), the Society operates the magazine, TV channels, a website, worldwide events, and other media operations. Overview The National Geographic Society was founded on 13 January 1888 "to increase and diffuse geographic knowledge". It is governed by a board of trustees whose 33 members include distinguished educators, business executives, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earendel (star)
WHL0137-LS, also known as Earendel, is a star in the constellation of Cetus. Discovered in 2022 by the Hubble Space Telescope, it is the earliest and most distant known star, at a comoving distance of . The previous furthest known star, MACS J1149 Lensed Star 1, also known as Icarus, at a comoving distance of , was discovered by Hubble in 2018. Stars like Earendel can be observed at cosmological distances thanks to the large magnification factors involved, that can exceed 1000. Other stars have been observed through this technique, such as Godzilla. Observation Earendel's discovery by the Hubble Space Telescope was reported on 30 March 2022. The star was detectable due to gravitational lensing caused by the presence of the galaxy cluster WHL0137-08 between it and the Earth, concentrating the light from the star. Computer simulations of the lensing effect suggest that Earendel's brightness was magnified between one thousand and forty thousand times. The dates of Hubble's expo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WHL0137-LS
WHL0137-LS, also known as Earendel, is a star in the constellation of Cetus. Discovered in 2022 by the Hubble Space Telescope, it is the earliest and most distant known star, at a comoving distance of . The previous furthest known star, MACS J1149 Lensed Star 1, also known as Icarus, at a comoving distance of , was discovered by Hubble in 2018. Stars like Earendel can be observed at cosmological distances thanks to the large magnification factors involved, that can exceed 1000. Other stars have been observed through this technique, such as Godzilla. Observation Earendel's discovery by the Hubble Space Telescope was reported on 30 March 2022. The star was detectable due to gravitational lensing caused by the presence of the galaxy cluster WHL0137-08 between it and the Earth, concentrating the light from the star. Computer simulations of the lensing effect suggest that Earendel's brightness was magnified between one thousand and forty thousand times. The dates of Hubble's expo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Icarus (star)
MACS J1149 Lensed Star 1, also known as Icarus,Other names include ''LS1'', ''MACS J1149 LS1'', ''MACS J1149 Lensed Star 1 (LS1)'' and ''MACS J1149+2223 Lensed Star 1'' is a blue supergiant star observed through a gravitational lens. It is the second most distant individual star to have been detected so far (second only to WHL0137-LS, a.k.a. Earendel, as of March 2022), at approximately 14 billion light-years from Earth ( redshift z=1.49; comoving distance of 14.4 billion light-years; lookback time of 9.34 billion years). Light from the star was emitted 4.4 billion years after the Big Bang. According to co-discoverer Patrick Kelly, the star is at least a hundred times more distant than the next-farthest non- supernova star observed, SDSS J1229+1122, and is the first magnified individual star seen. History In April and May 2018, the star was found in the course of studying the supernova SN Refsdal with the Hubble Space Telescope. Astronomer Patrick Kelly of the University ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MACS J1149 Lensed Star 1
MACS J1149 Lensed Star 1, also known as Icarus,Other names include ''LS1'', ''MACS J1149 LS1'', ''MACS J1149 Lensed Star 1 (LS1)'' and ''MACS J1149+2223 Lensed Star 1'' is a blue supergiant star observed through a gravitational lens. It is the second most distant individual star to have been detected so far (second only to WHL0137-LS, a.k.a. Earendel, as of March 2022), at approximately 14 billion light-years from Earth (redshift z=1.49; comoving distance of 14.4 billion light-years; Cosmic time, lookback time of 9.34 billion years). Light from the star was emitted 4.4 billion years after the Big Bang. According to co-discoverer Patrick Kelly, the star is at least a hundred times more distant than the next-farthest non-supernova star observed, SDSS J1229+1122, and is the first magnified individual star seen. History In April and May 2018, the star was found in the course of studying the supernova SN Refsdal with the Hubble Space Telescope. Astronomer Patrick Kelly of the Univer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravitational Lens
A gravitational lens is a distribution of matter (such as a cluster of galaxies) between a distant light source and an observer that is capable of bending the light from the source as the light travels toward the observer. This effect is known as gravitational lensing, and the amount of bending is one of the predictions of Albert Einstein's general theory of relativity. Treating light as corpuscles travelling at the speed of light, Newtonian physics also predicts the bending of light, but only half of that predicted by general relativity. Although Einstein made unpublished calculations on the subject in 1912, Orest Khvolson (1924) and Frantisek Link (1936) are generally credited with being the first to discuss the effect in print. However, this effect is more commonly associated with Einstein, who published an article on the subject in 1936. Fritz Zwicky posited in 1937 that the effect could allow galaxy clusters to act as gravitational lenses. It was not until 1979 that this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hubble Constant
Hubble's law, also known as the Hubble–Lemaître law, is the observation in physical cosmology that galaxies are moving away from Earth at speeds proportional to their distance. In other words, the farther they are, the faster they are moving away from Earth. The velocity of the galaxies has been determined by their redshift, a shift of the light they emit toward the red end of the visible spectrum. Hubble's law is considered the first observational basis for the expansion of the universe, and today it serves as one of the pieces of evidence most often cited in support of the Big Bang model. The motion of astronomical objects due solely to this expansion is known as the Hubble flow. It is described by the equation , with ''H''0 the constant of proportionality—the Hubble constant—between the "proper distance" ''D'' to a galaxy, which can change over time, unlike the comoving distance, and its speed of separation ''v'', i.e. the derivative of proper distance with respect t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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