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79-588: The Giant Magellan Telescope (GMT) is an extremely large telescope under construction, as part of the US Extremely Large Telescope Program. Baade telescope: Clay telescope: This program is a survey of stars searching for planets using the MIKE echelle spectrograph mounted on the 6.5 m Magellan II (Clay) telescope. In 2013, Clay (Magellan II) was equipped with an adaptive secondary mirror called MagAO which allowed it to take

158-470: A ∗ < 0.1 {\displaystyle a_{*}<0.1} , Belanger et al. (2006) a ∗ ∼ 0.22 {\displaystyle a_{*}\sim 0.22} , Meyer et al. (2006) a ∗ > 0.4 {\displaystyle a_{*}>0.4} , Genzel et al. (2003) a ∗ ∼ 0.52 {\displaystyle a_{*}\sim 0.52} and Daly et al. (2023)

237-404: A ∗ = 0.90 ± 0.06 {\displaystyle a_{*}=0.90\pm 0.06} . There are a number of stars in close orbit around Sagittarius A*, which are collectively known as "S stars". These stars are observed primarily in K band infrared wavelengths, as interstellar dust drastically limits visibility in visible wavelengths. This is a rapidly changing field—in 2011,

316-808: A rotating furnace , was completed on November 3, 2005. A third segment was cast in August 2013, the fourth in September 2015, the fifth in 2017, the sixth in 2021, and the last in 2023. Polishing of the first mirror was completed in November 2012. Ingersoll Machine Tools finished constructing a manufacturing facility to manufacture the Giant Magellan Telescope mount in Rockford, Illinois in December 2021. As of 2022, construction of

395-425: A 40,000 square foot facility to manufacture the Giant Magellan Telescope mount in Rockford, Illinois in December 2021. As of 2022, construction of the telescope mount was underway and is expected to be completed in 2025. The telescope mount consists of seven “cells” that hold and protect the telescope’s 18-ton primary mirrors. The mirror support system does not have a traditional internal load-carrying frame. Instead,

474-598: A black hole of four million solar masses. The flares are thought to originate from magnetic interactions in the very hot gas orbiting very close to Sagittarius A*. In July 2018, it was reported that S2 orbiting Sgr A* had been recorded at 7,650 km/s (17.1 million mph), or 2.55% the speed of light , leading up to the pericenter approach, in May 2018, at about 120  AU (18  billion   km ; 11 billion  mi ) (approximately 1,400 Schwarzschild radii ) from Sgr A*. At that close distance to

553-429: A black hole, beyond any reasonable doubt." On January 5, 2015, NASA reported observing an X-ray flare 400 times brighter than usual, a record-breaker, from Sgr A*. The unusual event may have been caused by the breaking apart of an asteroid falling into the black hole or by the entanglement of magnetic field lines within gas flowing into Sgr A*, according to astronomers. On 13 May 2019, astronomers using

632-499: A bright and very compact component, Sgr A*, was discovered on February 13 and 15, 1974, by Balick and Robert L Brown using the baseline interferometer of the National Radio Astronomy Observatory . The name Sgr A* was coined by Brown in a 1982 paper because the radio source was "exciting", and excited states of atoms are denoted with asterisks. Since the 1980s, it has been evident that

711-428: A closed-cycle forced-air convection system to maintain a thermal equilibrium within the telescope enclosure and reduce ambient thermal gradients across the primary mirror surface. The enclosure design provides the telescope pier with a seismic isolation system that can survive the strongest earthquakes expected over the 50-year lifetime of the observatory and will allow the telescope to quickly return to operations after

790-529: A film of oil (50 microns thick), being supported by a number of hydrostatic bearings to allow the telescope mount to glide frictionlessly in three degrees of freedom. In October 2019, GMTO Corporation announced the signing of a contract with German company MT Mechatronics (subsidiary of OHB SE) and Illinois-based Ingersoll Machine Tools, to design, build and install the Giant Magellan Telescope’s structure. Ingersoll Machine Tools finished constructing

869-420: A potential intermediate-mass black hole , referred to as GCIRS 13E , orbiting 3 light-years from Sagittarius A*. This black hole of 1,300 solar masses is within a cluster of seven stars. This observation may add support to the idea that supermassive black holes grow by absorbing nearby smaller black holes and stars. After monitoring stellar orbits around Sagittarius A* for 16 years, Gillessen et al. estimated

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948-401: A primary mirror diameter of 25.4 meters, it is expected to be the largest Gregorian telescope ever built, observing in optical and mid-infrared wavelengths (320–25,000 nm). Commissioning of the telescope is anticipated in the early 2030s. The GMT will feature seven of the world's largest mirrors, collectively providing a light-collecting area of 368 square meters. It is expected to have

1027-606: A resolving power approximately 10 times greater than the Hubble Space Telescope and four times greater than the James Webb Space Telescope . However, it will not be able to observe in the same infrared frequencies as space-based telescopes. The GMT will be used to explore a wide range of astrophysical phenomena, including the search for signs of life on exoplanets and the study of the cosmic origins of chemical elements. The casting of

1106-426: A ring-like structure, which has a diameter about 5.2 times the black hole's Schwarzschild radius (10 μas). For a black hole of around 4 million solar masses, this corresponds to a size of approximately 52  μas , which is consistent with the observed overall size of about 50 μas, the size (apparent diameter) of the black hole Sgr A* itself being 20 μas. Recent lower resolution observations revealed that

1185-426: A volume with a radius no more than 17 light-hours (120  AU  [18  billion   km ; 11 billion  mi ]). Later observations of the star S14 showed the mass of the object to be about 4.1 million solar masses within a volume with radius no larger than 6.25 light-hours (45 AU [6.7 billion km; 4.2 billion mi]). S175 passed within a similar distance. For comparison,

1264-543: Is a supermassive compact object, for which a black hole was the only plausible explanation at the time. In May 2022, astronomers released the first image of the accretion disk around the horizon of Sagittarius A*, confirming it to be a black hole, using the Event Horizon Telescope , a world-wide network of radio observatories. This is the second confirmed image of a black hole, after Messier 87's supermassive black hole in 2019. The black hole itself

1343-411: Is designed to take advantage of the telescope’s four observing modes. The telescope will have an advanced fiber-optic system that uses tiny robotic positioners to expand the capabilities of the spectrographs by allowing them to access the highest resolution of all telescopes in the 30-meter class over a full field of view of 20 arcminutes. Using this system, it is possible to observe multiple targets over

1422-401: Is easily visible in satellite imagery at 34°09′21″N 118°08′00″W  /  34.15591°N 118.13345°W  / 34.15591; -118.13345  ( Giant Magellan Telescope outline drawing ) . The Giant Magellan Telescope’s Adaptive Secondary Mirror consists of seven segments about 1.1 meters in diameter. They are deformable “adaptive optics” mirrors tasked with correcting

1501-518: Is estimated to be a million times stronger than the current output from Sgr A* and is comparable with a typical active galactic nucleus . In 2011 this conclusion was supported by Japanese astronomers observing the Milky Way's center with the Suzaku satellite. In July 2019, astronomers reported finding a star, S5-HVS1 , traveling 1,755 km/s (3.93 million mph) or 0.006 c . The star

1580-562: Is in the Grus (or Crane) constellation in the southern sky, and about 29,000 light-years from Earth, and may have been propelled out of the Milky Way galaxy after interacting with Sagittarius A*. Several values have been given for its spin parameter a ∗ = c J G M 2 {\displaystyle a_{*}={\frac {cJ}{GM^{2}}}} ; some examples are Fragione & Loeb (2020)

1659-474: Is maintained for the possibility of stars approaching the event horizon close enough to be disrupted, but none of these stars are expected to suffer that fate. As of 2020 , S4714 is the current record holder of closest approach to Sagittarius A*, at about 12.6 AU (1.88 billion km), almost as close as Saturn gets to the Sun, traveling at about 8% of the speed of light. These figures given are approximate,

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1738-504: Is not seen, only nearby objects whose behavior is influenced by the black hole. The observed radio and infrared energy emanates from gas and dust heated to millions of degrees while falling into the black hole. On May 12, 2022, the first image of Sagittarius A* was released by the Event Horizon Telescope Collaboration . The image, which is based on radio interferometer data taken in 2017, confirms that

1817-695: Is one of a new class of telescopes called extremely large telescopes with each design being much larger than existing ground-based telescopes. Other planned extremely large telescopes include the Extremely Large Telescope and the Thirty Meter Telescope . The Giant Magellan Telescope is the work of the GMTO Corporation, an international consortium of research institutions representing seven countries from Australia, Brazil, Chile, Israel, South Korea, Taiwan, and

1896-472: Is that the outer six mirror segments will be off-axis , and although identical to each other, will not be individually radially symmetrical, necessitating a modification of the usual polishing and testing procedures. The mirrors are being constructed by the University of Arizona 's Steward Observatory Richard F. Caris Mirror Lab. The casting of each mirror uses 20 tons of E6 borosilicate glass from

1975-551: Is the supermassive black hole at the Galactic Center of the Milky Way . Viewed from Earth, it is located near the border of the constellations Sagittarius and Scorpius , about 5.6° south of the ecliptic , visually close to the Butterfly Cluster (M6) and Lambda Scorpii . The object is a bright and very compact astronomical radio source . The name Sagittarius A* distinguishes the compact source from

2054-430: Is the only 30-meter class telescope with ground layer adaptive optics over a full field of view. The Giant Magellan Telescope's Gregorian design can accommodate up to 10 visible to mid-infrared science instruments, from wide field imagers and spectrographs that reach hundreds of objects at one time, to high-resolution imagers and spectrographs that can study exoplanets and even find biosignatures . Each science instrument

2133-423: Is used to maintain a thermal equilibrium within the telescope enclosure and reduce thermal gradients across the primary mirror surface. As a precursor to the fabrication of the seven mirror support systems, a full-scale prototype has also been built to validate design decisions and demonstrate the performance. In April 2023, OHB Italia S.p.A. finished manufacturing and testing the first of seven mirror covers for

2212-520: The CSIRO radio telescope at Potts Hill Reservoir , in Sydney discovered a discrete and bright "Sagittarius-Scorpius" radio source, which after further observation with the 80-foot (24-metre) CSIRO radio telescope at Dover Heights was identified in a letter to Nature as the probable Galactic Center. Later observations showed that Sagittarius A actually consists of several overlapping sub-components;

2291-701: The Carnegie Institution for Science since 1960. Las Campanas was selected as the location for the GMT due to its exceptional astronomical seeing conditions and clear weather throughout much of the year. The sparse population in the surrounding Atacama Desert, combined with favorable geographical conditions, ensures minimal atmospheric and light pollution . This makes the area one of the best locations on Earth for long-term astronomical observation. The observatory's southern hemisphere location also provides access to significant astronomical targets, including

2370-500: The ESO 's Very Large Telescope in Chile, concluded alternatively that the cloud, rather than being isolated, might be a dense clump within a continuous but thinner stream of matter, and would act as a constant breeze on the disk of matter orbiting the black hole, rather than sudden gusts that would have caused high brightness as they hit, as originally expected. Supporting this hypothesis, G1,

2449-477: The Keck Observatory witnessed a sudden brightening of Sgr A*, which became 75 times brighter than usual, suggesting that the supermassive black hole may have encountered another object. In June 2023, unexplained filaments of radio energy were found associated with Sagittarius A*. In a paper published on October 31, 2018, the discovery of conclusive evidence that Sagittarius A* is a black hole

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2528-498: The Ohara Corporation of Japan and takes about 12–13 weeks. After being cast, they need to cool for about six months. Each takes approximately 4 years to cast and polish, obtaining a finish that is so smooth that the highest peaks and valleys are smaller than 1/1000 of the width of a human hair. As this was an off-axis segment, a wide array of new optical tests and laboratory infrastructure had to be developed to polish

2607-525: The SOFIA aircraft revealed that magnetic fields cause the surrounding ring of gas and dust, temperatures of which range from −280 to 17,500 °F (99.8 to 9,977.6 K; −173.3 to 9,704.4 °C), to flow into an orbit around Sagittarius A*, keeping black hole emissions low. Astronomers have been unable to observe Sgr A* in the optical spectrum because of the effect of 25 magnitudes of extinction (absorption and scattering) by dust and gas between

2686-533: The Schwarzschild radius is 0.08 AU (12 million km; 7.4 million mi). They also determined the distance from Earth to the Galactic Center (the rotational center of the Milky Way), which is important in calibrating astronomical distance scales, as 8,000 ± 600 parsecs (30,000 ± 2,000 light-years ). In November 2004, a team of astronomers reported the discovery of

2765-418: The GMT facility Adaptive Optics System. Science drivers for the Giant Magellan Telescope include studying planets in the habitable zones of their parent star in the search for life; the nature of dark matter, dark energy, gravity, and many other aspects of fundamental physics; the formation and evolution of the first stars and galaxies; and how black holes and galaxies co-evolve. The Giant Magellan Telescope

2844-414: The GMT's primary mirrors began in 2005, and construction at the site started in 2015. By 2023, all seven primary mirrors had been cast, the first of seven adaptive secondary mirrors was under construction, and the telescope mount was in the manufacturing stage. Other subsystems of the telescope were in the final stages of design. The project, with an estimated cost of USD $ 2 billion, is being developed by

2923-625: The GMTO Corporation, a consortium of research institutions from seven countries: Australia, Brazil, Chile, Israel, South Korea, Taiwan, and the United States. The telescope is located at Las Campanas Observatory, which is also home to the Magellan Telescopes . The observatory is situated approximately 115 km (71 mi) north-northeast of La Serena , and 180 km (112 mi) south of Copiapó , at an altitude of 2,516 m (8,255 ft). The site has been owned by

3002-470: The Giant Magellan. In just over two minutes, the covers will retract in unison to protect the world’s largest mirrors when not in use. The telescope will use seven of the world's largest mirrors as primary mirror segments, each 8.417 m (27.61 ft) in diameter. These segments will then be arranged with one mirror in the center and the other six arranged symmetrically around it. The challenge

3081-525: The LBT, the original MagAO mirror had a diameter of 36 inches (0.91 m). However, the edge of the mirror was broken. Technicians at Steward Observatory were able to cut the mirror to 33.5 inches (0.85 m) in diameter, thereby removing the broken edge. Giant Magellan Telescope The Giant Magellan Telescope (GMT) is a ground-based, extremely large telescope currently under construction at Las Campanas Observatory in Chile's Atacama Desert . With

3160-560: The Sun at perihelion . The proper motion of Sgr A* is approximately −2.70  mas per year for the right ascension and −5.6 mas per year for the declination . The telescope's measurement of these black holes tested Einstein's theory of relativity more rigorously than has previously been done, and the results match perfectly. In 2019, measurements made with the High-resolution Airborne Wideband Camera-Plus (HAWC+) mounted in

3239-584: The United States. The GMTO Corporation is a nonprofit 501(c)(3) organization with offices in Pasadena, California and Santiago, Chile. The organization has an established relationship with the Chilean government, having been recognized through a presidential decree as an “international organization” in Chile. The telescope operates under a cooperative agreement with the University of Chile, granting 10% of

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3318-486: The University of California, Los Angeles. a , e , i , Ω and ω are standard orbital elements , with a measured in arcseconds . Tp is the epoch of pericenter passage, P is the orbital period in years and Kmag is the infrared K-band apparent magnitude of the star. q and v are the pericenter distance in AU and pericenter speed in percent of the speed of light . First noticed as something unusual in images of

3397-501: The analysis. Their result gives an overall angular size for the source of 51.8 ± 2.3  μas . At a distance of 26,000 light-years (8,000 parsecs ), this yields a diameter of 51.8 million kilometres (32.2 million miles). For comparison, Earth is 150 million kilometres (1.0 astronomical unit ; 93 million miles ) from the Sun , and Mercury is 46 million km (0.31 AU; 29 million mi) from

3476-551: The atmospheric distortion of the light gathered by the telescope. The Adaptive Secondary Mirrors consist of a thin sheet of glass that is bonded to more than 7000 independently controlled voice coil actuators. Each segment can deform/reshape their 2-millimeter-thick surface 2,000 times per second to correct for the optical blurring effect of Earth’s atmosphere. The first segment is under construction as of August 2022 and will be completed in 2024. The Giant Magellan Telescope will have three modes of adaptive optics. The Giant Magellan

3555-401: The back of the primary mirrors to correct for the effects of gravity and temperature variations on the seven, 8.4 meter diameter primary mirrors. In addition, fourteen air handler units using CO2 based refrigeration – the first system of its kind used for telescopes – are mounted to the interior of the mirror support system to circulate the air. A closed-cycle forced-air convection system

3634-564: The black hole, Einstein 's theory of general relativity (GR) predicts that S2 would show a discernible gravitational redshift in addition to the usual velocity redshift; the gravitational redshift was detected, in agreement with the GR prediction within the 10 percent measurement precision. Assuming that general relativity is still a valid description of gravity near the event horizon, the Sagittarius A* radio emissions are not centered on

3713-455: The black hole, but arise from a bright spot in the region around the black hole, close to the event horizon, possibly in the accretion disc , or a relativistic jet of material ejected from the disc. If the apparent position of Sagittarius A* were exactly centered on the black hole, it would be possible to see it magnified beyond its size, because of gravitational lensing of the black hole. According to general relativity , this would result in

3792-402: The black hole. The black hole itself is thought to emit only Hawking radiation at a negligible temperature, on the order of 10 kelvin . The European Space Agency 's gamma-ray observatory INTEGRAL observed gamma rays interacting with the nearby giant molecular cloud Sagittarius B2 , causing X-ray emission from the cloud. The total luminosity from this outburst ( L ≈1,5 × 10 erg/s)

3871-463: The center of the Milky Way in 2002, the gas cloud G2, which has a mass about three times that of Earth, was confirmed to be likely on a course taking it into the accretion zone of Sgr A* in a paper published in Nature in 2012. Predictions of its orbit suggested it would make its closest approach to the black hole (a perinigricon ) in early 2014, when the cloud was at a distance of just over 3,000 times

3950-541: The center of the Milky Way. The average rate of accretion onto Sgr A* is unusually small for a black hole of its mass and is only detectable because it is so close to Earth. It was thought that the passage of G2 in 2013 might offer astronomers the chance to learn much more about how material accretes onto supermassive black holes. Several astronomical facilities observed this closest approach, with observations confirmed with Chandra , XMM , VLA , INTEGRAL , Swift , Fermi and requested at VLT and Keck . Simulations of

4029-531: The central component of Sgr A* is likely a black hole. In 1994, infrared and sub-millimetre spectroscopy studies by a Berkeley team involving Nobel Laureate Charles H. Townes and future Nobel Prize Winner Reinhard Genzel showed that the mass of Sgr A* was tightly concentrated and on the order of 3 million Suns. On October 16, 2002, an international team led by Reinhard Genzel at the Max Planck Institute for Extraterrestrial Physics reported

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4108-495: The cloud to the black hole, which was described as a lack of "fireworks" and a "flop". Astronomers from the UCLA Galactic Center Group published observations obtained on March 19 and 20, 2014, concluding that G2 was still intact (in contrast to predictions for a simple gas cloud hypothesis) and that the cloud was likely to have a central star. An analysis published on July 21, 2014, based on observations by

4187-588: The entire field with one or more of the spectrographs This enables the telescope to see fainter objects with unrivaled resolution and sensitivity. The advantage is extremely powerful for spectroscopy and the precise measurements of distances, dynamics, chemistry, and masses of celestial objects in deep space. Additionally the Commissioning Camera (ComCam) will be used to validate the Ground Layer Adaptive Optics performance of

4266-467: The formal uncertainties being 12.6 ± 9.3 AU and 23,928 ± 8,840 km/s . Its orbital period is 12 years, but an extreme eccentricity of 0.985 gives it the close approach and high velocity. An excerpt from a table of this cluster (see Sagittarius A* cluster ), featuring the most prominent members. In the below table, id1 is the star's name in the Gillessen catalog and id2 in the catalog of

4345-484: The galactic center of the Milky Way , the nearest supermassive black hole ( Sagittarius A* ), the nearest star to the Sun ( Proxima Centauri ), the Magellanic Clouds , and numerous nearby galaxies and exoplanets. The Giant Magellan Telescope’s Gregorian design will produce the highest possible image resolution of the universe over the widest field of view with only two light collecting surfaces, making it

4424-502: The larger (and much brighter) Sagittarius A (Sgr A) region in which it is embedded. Sgr A* was discovered in 1974 by Bruce Balick  [ de ] and Robert L. Brown, and the asterisk * was assigned in 1982 by Brown, who understood that the strongest radio emission from the center of the galaxy appeared to be due to a compact non-thermal radio object. The observations of several stars orbiting Sagittarius A*, particularly star S2 , have been used to determine

4503-514: The line-of-sight so these could be subtracted from the images. The VLBI radio observations of Sagittarius A* could also be aligned centrally with the NIR images, so the focus of S2's elliptical orbit was found to coincide with the position of Sagittarius A*. From examining the Keplerian orbit of S2, they determined the mass of Sagittarius A* to be 4.1 ± 0.6 million solar masses , confined in

4582-412: The low luminosity of the radio and infrared emission lines, imply that the Milky Way is not a Seyfert galaxy . Ultimately, what is seen is not the black hole itself, but observations that are consistent only if there is a black hole present near Sgr A*. In the case of such a black hole, the observed radio and infrared energy emanates from gas and dust heated to millions of degrees while falling into

4661-485: The mass and upper limits on the radius of the object. Based on mass and increasingly precise radius limits, astronomers have concluded that Sagittarius A* must be the central supermassive black hole of the Milky Way galaxy. The current best estimate of its mass is 4.297 ± 0.012 million solar masses . Reinhard Genzel and Andrea Ghez were awarded the 2020 Nobel Prize in Physics for their discovery that Sagittarius A*

4740-402: The mirror. The intention is to build seven identical off-axis mirrors, so that a spare is available to substitute for a segment being recoated, a 1–2 week (per segment) process required every 1–2 years. While the complete telescope will use seven mirrors, it is planned to begin operation with four mirrors. Segments 1–3 are complete. Segments 4–6 are undergoing polishing and testing. Segment 7

4819-515: The more frequent, but less intense seismic events that are experienced several times per month. In March 2022, engineering and architecture firm IDOM was awarded the contract to finalize the telescope’s enclosure design by 2024. The telescope mount structure is a 39 meters tall alt-azimuth design that will stand on a pier that is 22 meters in diameter. The structure will weigh 1,800 tons without mirrors and instruments. With mirrors and instruments, it will weigh 2,100 tons. This structure will float on

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4898-411: The most optically proficient of all extremely large telescopes in the 30-meter-class. Site preparation began with the first blast to level the mountain peak on March 23, 2012. In November 2015, construction was started at the site, with a ground-breaking ceremony. In January 2018, WSP was awarded the contract to manage construction of the Giant Magellan Telescope. The casting of the first mirror, in

4977-405: The object contains a black hole. This is the second image of a black hole. This image took five years of calculations to process. The data was collected by eight radio observatories at six geographical sites. Radio images are produced from data by aperture synthesis , usually from night-long observations of stable sources. The radio emission from Sgr A* varies on the order of minutes, complicating

5056-595: The object's mass at 4.31 ± 0.38 million solar masses. The result was announced in 2008 and published in The Astrophysical Journal in 2009. Reinhard Genzel , team leader of the research, said the study has delivered "what is now considered to be the best empirical evidence that supermassive black holes do really exist. The stellar orbits in the Galactic Center show that the central mass concentration of four million solar masses must be

5135-751: The observation of the motion of the star S2 near Sagittarius A* throughout a period of ten years. According to the team's analysis, the data ruled out the possibility that Sgr A* contains a cluster of dark stellar objects or a mass of degenerate fermions , strengthening the evidence for a massive black hole. The observations of S2 used near-infrared (NIR) interferometry (in the Ks-band, i.e. 2.1  μm ) because of reduced interstellar extinction in this band. SiO masers were used to align NIR images with radio observations, as they can be observed in both NIR and radio bands. The rapid motion of S2 (and other nearby stars) easily stood out against slower-moving stars along

5214-457: The observing time to astronomers working at Chilean institutions. The following organizations are members of the consortium developing the telescope. The Giant Magellan Telescope is a part of the US Extremely Large Telescope Program (US-ELTP), as of 2018 . The US-ELTP will provide US-based astronomers with U.S. National Science Foundation funded all-sky observing access to both the Giant Magellan Telescope and Thirty Meter Telescope. The program

5293-529: The orbits of the most prominent stars then known were plotted in the diagram at left, showing a comparison between their orbits and various orbits in the solar system. Since then, S62 has been found to approach even more closely than those stars. The high velocities and close approaches to the supermassive black hole makes these stars useful to establish limits on the physical dimensions of Sagittarius A*, as well as to observe general-relativity associated effects like periapse shift of their orbits. An active watch

5372-415: The passage were made before it happened by groups at ESO and Lawrence Livermore National Laboratory (LLNL). As the cloud approached the black hole, Daryl Haggard said, "It's exciting to have something that feels more like an experiment", and hoped that the interaction would produce effects that would provide new information and insights. Nothing was observed during and after the closest approach of

5451-510: The radio source of Sagittarius A* is symmetrical. Simulations of alternative theories of gravity depict results that may be difficult to distinguish from GR. However, a 2018 paper predicts an image of Sagittarius A* that is in agreement with recent observations; in particular, it explains the small angular size and the symmetrical morphology of the source. The mass of Sagittarius A* has been estimated in two different ways: The comparatively small mass of this supermassive black hole , along with

5530-442: The radius of the event horizon (or ≈260 AU, 36 light-hours) from the black hole. G2 has been observed to be disrupting since 2009, and was predicted by some to be completely destroyed by the encounter, which could have led to a significant brightening of X-ray and other emission from the black hole. Other astronomers suggested the gas cloud could be hiding a dim star, or a binary star merger product, which would hold it together against

5609-519: The sharpest visible-light images to date, capable of resolving objects 0.02 arcseconds across—equivalent to a dime (1.8 cm) seen from 100 miles (160 km) away. MagAO was originally intended for the Large Binocular Telescope (LBT), but the secondary mirror was damaged before it could be installed. The project leader Laird Close and his team were able to repair and repurpose the broken mirror for use on Magellan II. As built for

5688-464: The source and Earth. In April 1933, Karl Jansky , considered one of the fathers of radio astronomy, discovered that a radio signal was coming from a location in the direction of the constellation of Sagittarius, towards the center of the Milky Way. The radio source later became known as Sagittarius A . His observations did not extend quite as far south as we now know to be the Galactic Center. Observations by Jack Piddington and Harry Minnett using

5767-403: The strength comes from its unique shape and external shell. This allows the telescope mount to have a compact and lightweight design for its size. It also makes the telescope extremely stiff and stable so that it can resist image quality interruptions from wind and mechanical vibrations. The “cell” primary mirror support system contains “active optics” with pneumatic actuators that will push on

5846-474: The telescope mount was underway. The structure is expected to be delivered to Chile at the end of 2025. The Giant Magellan Telescope enclosure is a 65-meter-tall structure that shelters the telescope’s mirrors and components from the extreme weather and earthquakes in the Atacama Desert, Chile. The 4,800-ton enclosure can complete a full rotation in a little more than three minutes and is designed with

5925-425: The tidal forces of Sgr A*, allowing the ensemble to pass by without any effect. In addition to the tidal effects on the cloud itself, it was proposed in May 2013 that, prior to its perinigricon, G2 might experience multiple close encounters with members of the black-hole and neutron-star populations thought to orbit near the Galactic Center, offering some insight to the region surrounding the supermassive black hole at

6004-467: The very large aperture and advanced adaptive optics. Image quality is projected at a 20 arcminute field of view, correctable from 0–20 arcminutes. The images will be sharp enough to resolve the torch engraved on a U.S. dime from nearly 160 kilometers (100 miles) away and expected to exceed that of the Hubble Space Telescope . The Carnegie Observatories office in Pasadena has an outline of the Giant Magellan primary mirror array painted in its parking lot. It

6083-571: Was announced. Using the GRAVITY interferometer and the four telescopes of the Very Large Telescope (VLT) to create a virtual telescope 130 metres (430 feet) in diameter, astronomers detected clumps of gas moving at about 30% of the speed of light. Emission from highly energetic electrons very close to the black hole was visible as three prominent bright flares. These exactly match theoretical predictions for hot spots orbiting close to

6162-496: Was planned for casting in 2023. The primary mirror array will have a focal ratio (focal length divided by diameter) of f/0.71. For an individual segment – one third that diameter – this results in a focal ratio of f/2.14. The overall focal ratio of the complete telescope will be f/8 and the optical prescription is an aplanatic Gregorian telescope . Like all modern large telescopes it will make use of adaptive optics . Scientists expect very high quality images due to

6241-578: Was ranked as the highest ground-based priority in the National Academy of Sciences Astro2020 Decadal Survey which noted that the US-ELTP will provide “observational capabilities unmatched in space or the ground and open an enormous discovery space for new observations and discoveries not yet anticipated." Sagittarius A* Sagittarius A* , abbreviated as Sgr A* ( / ˈ s æ dʒ ˈ eɪ s t ɑːr / SADGE - AY -star ),

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