In physics, redshift is a phenomenon where electromagnetic radiation from an object undergoes an increase in wavelength. Whether or not the radiation is visible, "redshift" means an increase in wavelength, equivalent to a decrease in wave frequency and photon energy, in accordance with the wave and quantum theories of light. Neither the emitted nor perceived light is red. Examples of redshifting are a gamma ray perceived as an X-ray, or visible light perceived as radio waves; the opposite of a redshift is energy increases. However, redshift is a more common term and sometimes blueshift is referred to as negative redshift. There are three main causes of red in astronomy and cosmology: Objects move apart in space; this is an example of the Doppler effect. Space itself expands; this is known as cosmological redshift. All sufficiently distant light sources show redshift corresponding to the rate of increase in their distance from Earth, known as Hubble's Law. Gravitational redshift is a relativistic effect observed due to strong gravitational fields, which distort spacetime and exert a force on light and other particles.
Knowledge of redshifts and blueshifts has been used to develop several terrestrial technologies such as Doppler radar and radar guns. Redshifts are seen in the spectroscopic observations of astronomical objects, its value is represented by the letter z. A special relativistic redshift formula can be used to calculate the redshift of a nearby object when spacetime is flat. However, in many contexts, such as black holes and Big Bang cosmology, redshifts must be calculated using general relativity. Special relativistic and cosmological redshifts can be understood under the umbrella of frame transformation laws. There exist other physical processes that can lead to a shift in the frequency of electromagnetic radiation, including scattering and optical effects; the history of the subject began with the development in the 19th century of wave mechanics and the exploration of phenomena associated with the Doppler effect. The effect is named after Christian Doppler, who offered the first known physical explanation for the phenomenon in 1842.
The hypothesis was tested and confirmed for sound waves by the Dutch scientist Christophorus Buys Ballot in 1845. Doppler predicted that the phenomenon should apply to all waves, in particular suggested that the varying colors of stars could be attributed to their motion with respect to the Earth. Before this was verified, however, it was found that stellar colors were due to a star's temperature, not motion. Only was Doppler vindicated by verified redshift observations; the first Doppler redshift was described by French physicist Hippolyte Fizeau in 1848, who pointed to the shift in spectral lines seen in stars as being due to the Doppler effect. The effect is sometimes called the "Doppler–Fizeau effect". In 1868, British astronomer William Huggins was the first to determine the velocity of a star moving away from the Earth by this method. In 1871, optical redshift was confirmed when the phenomenon was observed in Fraunhofer lines using solar rotation, about 0.1 Å in the red. In 1887, Vogel and Scheiner discovered the annual Doppler effect, the yearly change in the Doppler shift of stars located near the ecliptic due to the orbital velocity of the Earth.
In 1901, Aristarkh Belopolsky verified optical redshift in the laboratory using a system of rotating mirrors. The earliest occurrence of the term red-shift in print appears to be by American astronomer Walter S. Adams in 1908, in which he mentions "Two methods of investigating that nature of the nebular red-shift"; the word does not appear unhyphenated until about 1934 by Willem de Sitter indicating that up to that point its German equivalent, was more used. Beginning with observations in 1912, Vesto Slipher discovered that most spiral galaxies mostly thought to be spiral nebulae, had considerable redshifts. Slipher first reports on his measurement in the inaugural volume of the Lowell Observatory Bulletin. Three years he wrote a review in the journal Popular Astronomy. In it he states that "the early discovery that the great Andromeda spiral had the quite exceptional velocity of –300 km showed the means available, capable of investigating not only the spectra of the spirals but their velocities as well."
Slipher reported the velocities for 15 spiral nebulae spread across the entire celestial sphere, all but three having observable "positive" velocities. Subsequently, Edwin Hubble discovered an approximate relationship between the redshifts of such "nebulae" and the distances to them with the formulation of his eponymous Hubble's law; these observations corroborated Alexander Friedmann's 1922 work, in which he derived the Friedmann-Lemaître equations. They are today considered strong evidence for the Big Bang theory; the spectrum of light that comes from a single source can be measured. To determine the redshift, one searches for features in the spectrum such as absorption lines, emission lines, or other variations in light intensity. If found, these featur
Right ascension is the angular distance of a particular point measured eastward along the celestial equator from the Sun at the March equinox to the point above the earth in question. When paired with declination, these astronomical coordinates specify the direction of a point on the celestial sphere in the equatorial coordinate system. An old term, right ascension refers to the ascension, or the point on the celestial equator that rises with any celestial object as seen from Earth's equator, where the celestial equator intersects the horizon at a right angle, it contrasts with oblique ascension, the point on the celestial equator that rises with any celestial object as seen from most latitudes on Earth, where the celestial equator intersects the horizon at an oblique angle. Right ascension is the celestial equivalent of terrestrial longitude. Both right ascension and longitude measure an angle from a primary direction on an equator. Right ascension is measured from the Sun at the March equinox i.e. the First Point of Aries, the place on the celestial sphere where the Sun crosses the celestial equator from south to north at the March equinox and is located in the constellation Pisces.
Right ascension is measured continuously in a full circle from that alignment of Earth and Sun in space, that equinox, the measurement increasing towards the east. As seen from Earth, objects noted to have 12h RA are longest visible at the March equinox. On those dates at midnight, such objects will reach their highest point. How high depends on their declination. Any units of angular measure could have been chosen for right ascension, but it is customarily measured in hours and seconds, with 24h being equivalent to a full circle. Astronomers have chosen this unit to measure right ascension because they measure a star's location by timing its passage through the highest point in the sky as the Earth rotates; the line which passes through the highest point in the sky, called the meridian, is the projection of a longitude line onto the celestial sphere. Since a complete circle contains 24h of right ascension or 360°, 1/24 of a circle is measured as 1h of right ascension, or 15°. A full circle, measured in right-ascension units, contains 24 × 60 × 60 = 86400s, or 24 × 60 = 1440m, or 24h.
Because right ascensions are measured in hours, they can be used to time the positions of objects in the sky. For example, if a star with RA = 1h 30m 00s is at its meridian a star with RA = 20h 00m 00s will be on the/at its meridian 18.5 sidereal hours later. Sidereal hour angle, used in celestial navigation, is similar to right ascension, but increases westward rather than eastward. Measured in degrees, it is the complement of right ascension with respect to 24h, it is important not to confuse sidereal hour angle with the astronomical concept of hour angle, which measures angular distance of an object westward from the local meridian. The Earth's axis rotates westward about the poles of the ecliptic, completing one cycle in about 26,000 years; this movement, known as precession, causes the coordinates of stationary celestial objects to change continuously, if rather slowly. Therefore, equatorial coordinates are inherently relative to the year of their observation, astronomers specify them with reference to a particular year, known as an epoch.
Coordinates from different epochs must be mathematically rotated to match each other, or to match a standard epoch. Right ascension for "fixed stars" near the ecliptic and equator increases by about 3.05 seconds per year on average, or 5.1 minutes per century, but for fixed stars further from the ecliptic the rate of change can be anything from negative infinity to positive infinity. The right ascension of Polaris is increasing quickly; the North Ecliptic Pole in Draco and the South Ecliptic Pole in Dorado are always at right ascension 18h and 6h respectively. The used standard epoch is J2000.0, January 1, 2000 at 12:00 TT. The prefix "J" indicates. Prior to J2000.0, astronomers used the successive Besselian epochs B1875.0, B1900.0, B1950.0. The concept of right ascension has been known at least as far back as Hipparchus who measured stars in equatorial coordinates in the 2nd century BC, but Hipparchus and his successors made their star catalogs in ecliptic coordinates, the use of RA was limited to special cases.
With the invention of the telescope, it became possible for astronomers to observe celestial objects in greater detail, provided that the telescope could be kept pointed at the object for a period of time. The easiest way to do, to use an equatorial mount, which allows the telescope to be aligned with one of its two pivots parallel to the Earth's axis. A motorized clock drive is used with an equatorial mount to cancel out the Earth's rotation; as the equatorial mount became adopted for observation, the equatorial coordinate system, which includes right ascension, was adopted at the same time for simplicity. Equatorial mounts could be pointed at objects with known right ascension and declination by the use of setting circles; the first star catalog to use right ascen
Palomar Observatory is an astronomical observatory located in San Diego County, United States, 145 kilometers southeast of Los Angeles, California, in the Palomar Mountain Range. It is operated by the California Institute of Technology located in Pasadena, California. Research time is granted to Caltech and its research partners, which include the Jet Propulsion Laboratory and Cornell University; the observatory operates several telescopes, including the 200-inch Hale Telescope and the 48-inch Samuel Oschin Telescope. In addition, other instruments and projects have been hosted at the observatory, such as the Palomar Testbed Interferometer and the historic 18-inch Schmidt telescope, Palomar Observatory's first telescope, dating from 1936. Astronomer George Ellery Hale, whose vision created the Palomar Observatory, built the world's largest telescope four times, he published an article, to become the 200-inch Palomar reflector. Hale hoped that the American people would understand and support his project though the country was in the depths of the Great Depression.
Hale followed this article with a letter to the International Education Board of the Rockefeller Foundation dated April 16, 1928 in which he requested funding for this project. In his letter, Hale stated: "No method of advancing science is so productive as the development of new and more powerful instruments and methods of research. A larger telescope would not only furnish the necessary gain in light space-penetration and photographic resolving power, but permit the application of ideas and devices derived chiefly from the recent fundamental advances in physics and chemistry." The 200-inch telescope is named after project manager George Hale. It was built by Caltech with a $6 million grant from the Rockefeller Foundation, using a Pyrex blank manufactured by Corning Glass Works under the direction of George McCauley after several years of unsuccessful attempts by General Electric under Dr. A. L. Ellis; the first steps toward funding the construction of the 200 inch telescope were taken by Hale in 1928 and included a 23-ton glass block cast by José Antonio de Artigas Sanz.
Dr. J. A. Anderson was the initial project manager assigned in the early 1940s; the telescope saw first light January 26, 1949 targeting NGC 2261. The American astronomer Edwin Powell Hubble was the first astronomer to use the telescope; the 200-inch telescope was the largest telescope in the world from 1949 until 1975, when the Russian BTA-6 telescope saw first light. Astronomers using the Hale Telescope have discovered distant objects at the edges of the known universe called quasars and have given us the first direct evidence of stars in distant galaxies, they have studied the structure and chemistry of intergalactic clouds, leading to an understanding of the synthesis of elements in the universe, have discovered thousands of asteroids. A one-tenth-scale engineering model of the telescope at Corning Community College in Corning, New York, home of the Corning Glass Works was used to discover at least one minor planet, 34419 Corning.† According to the Observatory's Public Affairs Office, Russell W. Porter was responsible for the Art Deco architecture of the Observatory's buildings, including the dome of the 200-inch Hale Telescope.
Porter was responsible for much of the technical design of the Hale Telescope and Schmidt Cameras, producing a series of cross-section engineering drawings. Porter worked on the designs in collaboration with Caltech committee members. Max Mason directed Theodore von Karman was involved in the engineering. Ira Sprague Bowen, 1948–1964 Horace Welcome Babcock, 1964–1978 Maarten Schmidt, 1978–1980 Gerry Neugebauer, 1980–1994 James Westphal, 1994–1997 Wallace Leslie William Sargent, 1997–2000 Richard Ellis, 2000–2006 Shrinivas Kulkarni, 2006–2018 Jonas Zmuidzinas, 2018– Much of the surrounding region of Southern California has adopted shielded lighting to reduce the light pollution that would affect the observatory; the 200-inch Hale Telescope was first proposed in 1928 and has been operational since 1948. It was the largest telescope in the world for 45 years. A 60-inch reflecting telescope is located in the Oscar Mayer Building, it was dedicated in 1970 to take some of the load off of the Hale Telescope.
This telescope was used to discover the first brown dwarf star. The 48-inch Samuel Oschin Telescope was started in 1938 and installed in 1948, it was called the 48-inch Schmidt, was dedicated to Samuel Oschin in 1986. The dwarf planet Eris was discovered using this instrument; the existence of Eris triggered the discussions in the international astronomy community that led to Pluto being re-classified as a dwarf planet. An 18-inch Schmidt camera became the first operational telescope at the Palomar in 1936. In the 1930s, Fritz Zwicky, a Caltech astronomer, discovered over 100 supernovae in other galaxies with this telescope and gathered the first evidence for dark matter. Comet Shoemaker-Levy 9 was discovered with this instrument in 1993, it is on display at the small museum/visitor center. The Palomar Testbed Interferometer was a multi-telescope instrument that permitted astronomers to make high resolution measurements of the sizes and positions of objects in space; the shapes of some bright stars have been measured with the PTI.
It operated from 1995 to 2008. The Palomar Planet Search Telescope, aka Sleuth, was a 0.1 m (3
European Southern Observatory
The European Southern Observatory, formally the European Organisation for Astronomical Research in the Southern Hemisphere, is a 16-nation intergovernmental research organization for ground-based astronomy. Created in 1962, ESO has provided astronomers with state-of-the-art research facilities and access to the southern sky; the organisation employs about 730 staff members and receives annual member state contributions of €162 million. Its observatories are located in northern Chile. ESO has operated some of the largest and most technologically advanced telescopes; these include the 3.6 m New Technology Telescope, an early pioneer in the use of active optics, the Very Large Telescope, which consists of four individual 8.2 m telescopes and four smaller auxiliary telescopes which can all work together or separately. The Atacama Large Millimeter Array observes the universe in the millimetre and submillimetre wavelength ranges, is the world's largest ground-based astronomy project to date, it was completed in March 2013 in an international collaboration by Europe, North America, East Asia and Chile.
Under construction is the Extremely Large Telescope. It will use a 39.3-metre-diameter segmented mirror, become the world's largest optical reflecting telescope when operational in 2024. Its light-gathering power will allow detailed studies of planets around other stars, the first objects in the universe, supermassive black holes, the nature and distribution of the dark matter and dark energy which dominate the universe. ESO's observing facilities have made astronomical discoveries and produced several astronomical catalogues, its findings include the discovery of the most distant gamma-ray burst and evidence for a black hole at the centre of the Milky Way. In 2004, the VLT allowed astronomers to obtain the first picture of an extrasolar planet orbiting a brown dwarf 173 light-years away; the High Accuracy Radial Velocity Planet Searcher instrument installed on the older ESO 3.6 m telescope led to the discovery of extrasolar planets, including Gliese 581c—one of the smallest planets seen outside the solar system.
The idea that European astronomers should establish a common large observatory was broached by Walter Baade and Jan Oort at the Leiden Observatory in the Netherlands in spring 1953. It was pursued by Oort, who gathered a group of astronomers in Leiden to consider it on June 21 that year. Thereafter, the subject was further discussed at the Groningen conference in the Netherlands. On January 26, 1954, an ESO declaration was signed by astronomers from six European countries expressing the wish that a joint European observatory be established in the southern hemisphere. At the time, all reflector telescopes with an aperture of 2 metres or more were located in the northern hemisphere; the decision to build the observatory in the southern hemisphere resulted from the necessity of observing the southern sky. Although it was planned to set up telescopes in South Africa, tests from 1955 to 1963 demonstrated that a site in the Andes was preferable. On November 15, 1963 Chile was chosen as the site for ESO's observatory.
The decision was preceded by the ESO Convention, signed 5 October 1962 by Belgium, France, the Netherlands and Sweden. Otto Heckmann was nominated as the organisation's first director general on 1 November 1962. A preliminary proposal for a convention of astronomy organisations in these five countries was drafted in 1954. Although some amendments were made in the initial document, the convention proceeded until 1960 when it was discussed during that year's committee meeting; the new draft was examined in detail, a council member of CERN highlighted the need for a convention between governments. The convention and government involvement became pressing due to rising costs of site-testing expeditions; the final 1962 version was adopted from the CERN convention, due to similarities between the organisations and the dual membership of some members. In 1966, the first ESO telescope at the La Silla site in Chile began operating; because CERN had sophisticated instrumentation, the astronomy organisation turned to the nuclear-research body for advice and a collaborative agreement between ESO and CERN was signed in 1970.
Several months ESO's telescope division moved into a CERN building in Geneva and ESO's Sky Atlas Laboratory was established on CERN property. ESO's European departments moved into the new ESO headquarters in Garching, Germany in 1980. Although ESO is headquartered in Germany, its telescopes and observatories are in northern Chile, where the organisation operates advanced ground-based astronomical facilities: La Silla, which hosts the New Technology Telescope Paranal, where the Very Large Telescope is located Llano de Chajnantor, which hosts the APEX submillimetre telescope and where ALMA, the Atacama Large Millimeter/submillimeter Array, is locatedThese are among the best locations for astronomical observations in the southern hemisphere. An ESO project is the Extremely Large Telescope, a 40-metre-class telescope based on a five-mirror design and the planned Overwhelmingly Large Telescope; the ELT will be the near-infrared telescope in the world. ESO began its design in early 2006, aimed to begin construction in 2012.
Construction work at the ELT site started in June 2014. As decided by the ESO council on 26 April 2010, a fou
The Hale Telescope is a 200-inch, f/3.3 reflecting telescope at the Palomar Observatory in California, US, named after astronomer George Ellery Hale. With funding from the Rockefeller Foundation in 1928, he orchestrated the planning and construction of the observatory, but with the project ending up taking 20 years he did not live to see its commissioning; the Hale was groundbreaking for its time, with double the diameter of the second-largest telescope, pioneered many new technologies in telescope mount design and in the design and fabrication of its large aluminum coated "honeycomb" low thermal expansion Pyrex mirror. It is still in active use; the Hale Telescope represented the technological limit in building large optical telescopes for over 30 years. It was the largest telescope in the world until the Russian BTA-6 was built in 1976, the second largest until the construction of the Keck Observatory Keck 1 in 1993. Hale supervised the building of the telescopes at the Mount Wilson Observatory with grants from the Carnegie Institution of Washington: the 60-inch telescope in 1908 and the 100-inch telescope in 1917.
These telescopes were successful, leading to the rapid advance in understanding of the scale of the Universe through the 1920s, demonstrating to visionaries like Hale the need for larger collectors. The chief optical designer for Hale's previous 100-inch telescope was George Willis Ritchey, who intended the new telescope to be of Ritchey–Chrétien design. Compared to the usual parabolic primary, this design would have provided sharper images over a larger usable field of view; however and Hale had a falling-out. With the project late and over budget, Hale refused to adopt the new design, with its complex curvatures, Ritchey left the project; the Mount Palomar Hale Telescope turned out to be the last world-leading telescope to have a parabolic primary mirror. In 1928 Hale secured a grant of $6 million from the Rockefeller Foundation for "the construction of an observatory, including a 200-inch reflecting telescope" to be administered by the California Institute of Technology, of which Hale was a founding member.
In the early 1930s, Hale selected a site at 1,700 m on Palomar Mountain in San Diego County, California, US, as the best site, less to be affected by the growing light pollution problem in urban centers like Los Angeles. The Corning Glass Works was assigned the task of making a 200-inch primary mirror. Construction of the observatory facilities and dome started in 1936, but because of interruptions caused by World War II, the telescope was not completed until 1948 when it was dedicated. Due to slight distortions of images, corrections were made to the telescope throughout 1949, it became available for research in 1950. The 200-inch telescope saw first light on January 26, 1949, at 10:06 pm PST under the direction of American astronomer Edwin Powell Hubble, targeting NGC 2261, an object known as Hubble's Variable Nebula; the photographs made were published in the astronomical literature and in the May 7, 1949 issue of Collier's Magazine. The telescope continues to be used every clear night for scientific research by astronomers from Caltech and their operating partners, Cornell University, the University of California, the Jet Propulsion Laboratory.
It is equipped with modern optical and infrared array imagers, an adaptive optics system. It has used lucky cam imaging, which in combination with adaptive optics pushed the mirror close to its theoretical resolution for certain types of viewing. One of the Corning Labs' glass test blanks for the Hale was used for the C. Donald Shane telescope's 120-inch primary mirror; the collecting area of the mirror is about 31,000 square inches. The Hale Telescope uses a special type of equatorial mount called a "horseshoe mount", a modified yoke mount that replaces the polar bearing with an open "horseshoe" structure that gives the telescope full access to the entire sky, including Polaris and stars near it; the optical tube assembly uses a Serrurier truss newly invented by Mark U. Serrurier of Caltech in Pasadena in 1935, designed to flex in such a way as to keep all of the optics in alignment. Theodore von Karman designed the lubrication system to avoid potential issues with turbulence during tracking.
The Hale Telescope was going to use a primary mirror of fused quartz manufactured by General Electric, but instead the primary mirror was cast in 1934 at Corning Glass Works in New York State using Corning's new material called Pyrex. Pyrex was chosen for its low expansion qualities so the large mirror would not distort the images produced when it changed shape due to temperature variations; the mirror was cast in a mold with 36 raised mold blocks. This created a honeycomb mirror that cut the amount of Pyrex needed down from over 40 short tons to just 20 short tons, making a mirror that would cool faster in use and have multiple "mounting points" on the back to evenly distribute its weight; the shape of a central hole was part of the mold so light could pass through the finished mirror when it was used in a Cassegrain configuration. While the glass was being poured into the mold during the first attempt to cast the 200-inch mirror, the intense heat caused several of the molding blocks to break loose and float to the top, ruining the mirror.
The defective mirror was used to test the annealing process. After the mold was re-engin
A constellation is a group of stars that forms an imaginary outline or pattern on the celestial sphere representing an animal, mythological person or creature, a god, or an inanimate object. The origins of the earliest constellations go back to prehistory. People used them to relate stories of their beliefs, 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. Adoption of constellations has changed over time. Many have changed in shape; some became popular. Others were limited to single nations; the 48 traditional Western constellations are Greek. They are given in Aratus' work Phenomena and Ptolemy's Almagest, though their origin predates these works by several centuries. Constellations in the far southern sky were added from the 15th century until the mid-18th century when European explorers began traveling to the Southern Hemisphere. Twelve ancient constellations belong to the zodiac.
The origins of the zodiac remain uncertain. In 1928, the International Astronomical Union formally accepted 88 modern constellations, with contiguous boundaries that together cover the entire celestial sphere. Any given point in a celestial coordinate system lies in one of the modern constellations; some astronomical naming systems include the constellation where a given celestial object is found to convey its approximate location in the sky. The Flamsteed designation of a star, for example, consists of a number and the genitive form of the constellation name. Other star patterns or groups called asterisms are not constellations per se but are used by observers to navigate the night sky. Examples of bright asterisms include the Pleiades and Hyades within the constellation Taurus or Venus' Mirror in the constellation of Orion.. Some asterisms, like the False Cross, are split between two constellations; the word "constellation" comes from the Late Latin term cōnstellātiō, which can be translated as "set of stars".
The Ancient Greek word for constellation is ἄστρον. A more modern astronomical sense of the term "constellation" is as a recognisable pattern of stars whose appearance is associated with mythological characters or creatures, or earthbound animals, or objects, it can specifically denote the recognized 88 named constellations used today. Colloquial usage does not draw a sharp distinction between "constellations" and smaller "asterisms", yet the modern accepted astronomical constellations employ such a distinction. E.g. the Pleiades and the Hyades are both asterisms, each lies within the boundaries of the constellation of Taurus. Another example is the northern asterism known as the Big Dipper or the Plough, composed of the seven brightest stars within the area of the IAU-defined constellation of Ursa Major; the southern False Cross asterism includes portions of the constellations Carina and Vela and the Summer Triangle.. A constellation, viewed from a particular latitude on Earth, that never sets below the horizon is termed circumpolar.
From the North Pole or South Pole, all constellations south or north of the celestial equator are circumpolar. Depending on the definition, equatorial constellations may include those that lie between declinations 45° north and 45° south, or those that pass through the declination range of the ecliptic or zodiac ranging between 23½° north, the celestial equator, 23½° south. Although stars in constellations appear near each other in the sky, they lie at a variety of distances away from the Earth. Since stars have their own independent motions, all constellations will change over time. After tens to hundreds of thousands of years, familiar outlines will become unrecognizable. Astronomers can predict the past or future constellation outlines by measuring individual stars' common proper motions or cpm by accurate astrometry and their radial velocities by astronomical spectroscopy; the earliest evidence for the humankind's identification of constellations comes from Mesopotamian inscribed stones and clay writing tablets that date back to 3000 BC.
It seems that the bulk of the Mesopotamian constellations were created within a short interval from around 1300 to 1000 BC. Mesopotamian constellations appeared in many of the classical Greek constellations; the oldest Babylonian star catalogues of stars and constellations date back to the beginning in the Middle Bronze Age, most notably the Three Stars Each texts and the MUL. APIN, an expanded and revised version based on more accurate observation from around 1000 BC. However, the numerous Sumerian names in these catalogues suggest that they built on older, but otherwise unattested, Sumerian traditions of the Early Bronze Age; the classical Zodiac is a revision of Neo-Babylonian constellations from the 6th century BC. The Greeks adopted the Babylonian constellations in the 4th century BC. Twenty Ptolemaic constellations are from the Ancient Near East. Another ten have the same stars but different names. Biblical scholar, E. W. Bullinger interpreted some of the creatures mentioned in the books of Ezekiel and Revelation as the middle signs of the four quarters of the Zodiac, with the Lion as Leo, the Bull as Taurus, the Man representing Aquarius and the Eagle standing in for Scorpio.
The biblical Book of Job also
SIMBAD is an astronomical database of objects beyond the Solar System. It is maintained by the Centre de données astronomiques de France. SIMBAD was created by merging the Catalog of Stellar Identifications and the Bibliographic Star Index as they existed at the Meudon Computer Centre until 1979, expanded by additional source data from other catalogues and the academic literature; the first on-line interactive version, known as Version 2, was made available in 1981. Version 3, developed in the C language and running on UNIX stations at the Strasbourg Observatory, was released in 1990. Fall of 2006 saw the release of Version 4 of the database, now stored in PostgreSQL, the supporting software, now written in Java; as of 10 February 2017, SIMBAD contains information for 9,099,070 objects under 24,529,080 different names, with 327,634 bibliographical references and 15,511,733 bibliographic citations. The minor planet 4692 SIMBAD was named in its honour. Planetary Data System – NASA's database of information on SSSB, maintained by JPL and Caltech.
NASA/IPAC Extragalactic Database – a database of information on objects outside the Milky Way maintained by JPL. NASA Exoplanet Archive – an online astronomical exoplanet catalog and data service Bibcode SIMBAD, Strasbourg SIMBAD, Harvard