Gravitational microlensing
Gravitational microlensing is an astronomical phenomenon due to the gravitational lens effect. It can be used to detect objects that range from the mass of a planet to the mass of a star, regardless of the light they emit. Astronomers can only detect bright objects that emit much light or large objects that block background light; these objects make up only a minor portion of the mass of a galaxy. Microlensing allows the study of objects that emit no light; when a distant star or quasar gets sufficiently aligned with a massive compact foreground object, the bending of light due to its gravitational field, as discussed by Einstein in 1915, leads to two distorted unresolved images resulting in an observable magnification. The time-scale of the transient brightening depends on the mass of the foreground object as well as on the relative proper motion between the background'source' and the foreground'lens' object. Since microlensing observations do not rely on radiation received from the lens object, this effect therefore allows astronomers to study massive objects no matter how faint.
It is thus an ideal technique to study the galactic population of such faint or dark objects as brown dwarfs, red dwarfs, white dwarfs, neutron stars, black holes, massive compact halo objects. Moreover, the microlensing effect is wavelength-independent, allowing use of distant source objects that emit any kind of electromagnetic radiation. Microlensing by an isolated object was first detected in 1989. Since microlensing has been used to constrain the nature of the dark matter, detect exoplanets, study limb darkening in distant stars, constrain the binary star population, constrain the structure of the Milky Way's disk. Microlensing has been proposed as a means to find dark objects like brown dwarfs and black holes, study starspots, measure stellar rotation, probe quasars including their accretion disks.. Microlensing was used in 2018 to detect Icarus, the most distant star observed. Microlensing is based on the gravitational lens effect. A massive object will bend the light of a bright background object.
This can generate multiple distorted and brightened images of the background source. Microlensing is caused by the same physical effect as strong lensing and weak lensing, but it is studied using different observational techniques. In strong and weak lensing, the mass of the lens is large enough that the displacement of light by the lens can be resolved with a high resolution telescope such as the Hubble Space Telescope. With microlensing, the lens mass is too low for the displacement of light to be observed but the apparent brightening of the source may still be detected. In such a situation, the lens will pass by the source in a reasonable amount of time, seconds to years instead of millions of years; as the alignment changes, the source's apparent brightness changes, this can be monitored to detect and study the event. Thus, unlike with strong and weak gravitational lenses, a microlensing event is a transient phenomenon from a human timescale perspective. Unlike with strong and weak lensing, no single observation can establish that microlensing is occurring.
Instead, the rise and fall of the source brightness must be monitored over time using photometry. This function of brightness versus time is known as a light curve. A typical microlensing light curve is shown below: A typical microlensing event like this one has a simple shape, only one physical parameter can be extracted: the time scale, related to the lens mass and velocity. There are several effects, that contribute to the shape of more atypical lensing events: Lens mass distribution. If the lens mass is not concentrated in a single point, the light curve can be different with caustic-crossing events, which may exhibit strong spikes in the light curve. In microlensing, this can be seen when the lens is a planetary system. Finite source size. In bright or quickly-changing microlensing events, like caustic-crossing events, the source star cannot be treated as an infinitesimally small point of light: the size of the star's disk and limb darkening can modify extreme features. Parallax. For events lasting for months, the motion of the Earth around the Sun can cause the alignment to change affecting the light curve.
Most focus is on the more unusual microlensing events those that might lead to the discovery of extrasolar planets. Although it has not yet been observed, another way to get more information from microlensing events that may soon be feasible involves measuring the astrometric shifts in the source position during the course of the event and resolving the separate images with interferometry. In practice, because the alignment needed is so precise and difficult to predict, microlensing is rare. Events, are found with surveys, which photometrically monitor tens of millions of potential source stars, every few days for several years. Dense background fields suitable for such surveys are nearby galaxies, such as the Magellanic Clouds and the Andromeda galaxy, the Milky Way bulge. In each case, the lens population studied comprises the objects between Earth and the source field: for the bulge, the lens population is the Milky Way disk stars, for external galaxies, the lens population is the Milky Way halo, as well as objects in the other galaxy itself.
The density and location of the objects in these lens populations determines the frequency of microlensing along that line of sight, characterized by a value known as the optical depth due to microlensing. (This
Charge-coupled device
A charge-coupled device is a device for the movement of electrical charge from within the device to an area where the charge can be manipulated, for example conversion into a digital value. This is achieved by "shifting" the signals between stages within the device one at a time. CCDs move charge between capacitive bins in the device, with the shift allowing for the transfer of charge between bins. In recent years CCD has become a major technology for digital imaging. In a CCD image sensor, pixels are represented by p-doped metal-oxide-semiconductors capacitors; these capacitors are biased above the threshold for inversion when image acquisition begins, allowing the conversion of incoming photons into electron charges at the semiconductor-oxide interface. Although CCDs are not the only technology to allow for light detection, CCD image sensors are used in professional and scientific applications where high-quality image data are required. In applications with less exacting quality demands, such as consumer and professional digital cameras, active pixel sensors known as complementary metal-oxide-semiconductors are used.
The charge-coupled device was invented in 1969 in the United States at AT&T Bell Labs by Willard Boyle and George E. Smith; the lab was working on semiconductor bubble memory when Boyle and Smith conceived of the design of what they termed, in their notebook, "Charge'Bubble' Devices". The device could be used as a shift register; the essence of the design was the ability to transfer charge along the surface of a semiconductor from one storage capacitor to the next. The concept was similar in principle to the bucket-brigade device, developed at Philips Research Labs during the late 1960s; the first patent on the application of CCDs to imaging was assigned to Michael Tompsett. The initial paper describing the concept listed possible uses as a memory, a delay line, an imaging device; the first experimental device demonstrating the principle was a row of spaced metal squares on an oxidized silicon surface electrically accessed by wire bonds. The first working CCD made with integrated circuit technology was a simple 8-bit shift register.
This device had input and output circuits and was used to demonstrate its use as a shift register and as a crude eight pixel linear imaging device. Development of the device progressed at a rapid rate. By 1971, Bell researchers led by Michael Tompsett were able to capture images with simple linear devices. Several companies, including Fairchild Semiconductor, RCA and Texas Instruments, picked up on the invention and began development programs. Fairchild's effort, led by ex-Bell researcher Gil Amelio, was the first with commercial devices, by 1974 had a linear 500-element device and a 2-D 100 x 100 pixel device. Steven Sasson, an electrical engineer working for Kodak, invented the first digital still camera using a Fairchild 100 x 100 CCD in 1975; the first KH-11 KENNEN reconnaissance satellite equipped with charge-coupled device array technology for imaging was launched in December 1976. Under the leadership of Kazuo Iwama, Sony started a large development effort on CCDs involving a significant investment.
Sony managed to mass-produce CCDs for their camcorders. Before this happened, Iwama died in August 1982. In January 2006, Boyle and Smith were awarded the National Academy of Engineering Charles Stark Draper Prize, in 2009 they were awarded the Nobel Prize for Physics, for their invention of the CCD concept. Michael Tompsett was awarded the 2010 National Medal of Technology and Innovation for pioneering work and electronic technologies including the design and development of the first charge coupled device imagers, he was awarded the 2012 IEEE Edison Medal "For pioneering contributions to imaging devices including CCD Imagers and thermal imagers". In a CCD for capturing images, there is a photoactive region, a transmission region made out of a shift register. An image is projected through a lens onto the capacitor array, causing each capacitor to accumulate an electric charge proportional to the light intensity at that location. A one-dimensional array, used in line-scan cameras, captures a single slice of the image, whereas a two-dimensional array, used in video and still cameras, captures a two-dimensional picture corresponding to the scene projected onto the focal plane of the sensor.
Once the array has been exposed to the image, a control circuit causes each capacitor to transfer its contents to its neighbor. The last capacitor in the array dumps its charge into a charge amplifier, which converts the charge into a voltage. By repeating this process, the controlling circuit converts the entire contents of the array in the semiconductor to a sequence of voltages. In a digital device, these voltages are sampled and stored in memory. Before the MOS capacitors are exposed to light, they are biased into the depletion region; the gate is biased at a positive potential, above the threshold for strong inversion, which will result in the creation
CNES
The National Centre for Space Studies is the French government space agency. Its headquarters are located in central Paris and it is under the supervision of the French Ministries of Defence and Research, it operates from the Toulouse Space Center and Guiana Space Centre, but has payloads launched from space centres operated by other countries. The president of CNES is Jean-Yves Le Gall. CNES is member of Institute of its Applications and Technologies; as of April 2018, CNES has the second largest national budget—€2.438 billion—of all the world's civilian space programs, after only NASA. CNES was established under President Charles de Gaulle in 1961. CNES was responsible for the training of French astronauts, until the last active CNES astronauts transferred to the European Space Agency in 2001; as of January 2015, CNES is working with Germany and a few other governments to start a modest research effort with the hope to propose a LOX/methane reusable launch vehicle by mid-2015. If built, flight testing would not start before 2026.
The design objective is to reduce both the cost and duration of reusable vehicle refurbishment, is motivated by the pressure of lower-cost competitive options with newer technological capabilities not found in the Ariane 6. 1947: CIEES/Hammaguir missile range and launch facility built for the French military in French Algeria. 1961 CNES founded. 1962 First Berenice rocket launched. 1964 Diamant Launch Vehicle introduced. 1963 CNES became the first—and only—space agency to launch a cat into space. 1965 First French satellite put in orbit. 1967 Hammaguir range closed. 1968 Toulouse Space Center completed. 1969 French Guiana Space Centre completed. 1973 Évry Space Centre completed. 2014 E-CORCE Earth observation satellite launched CNES concentrates on five areas: Access to space Civil applications of space Sustainable development Science and technology research Security and defence France was the third space power to achieve access to space after the USSR and USA, sharing technologies with Europe to develop the Ariane launcher family.
Commercial competition in space is fierce, so launch services must be tailored to space operators’ needs. The latest versions of the Ariane 5 launch vehicle can launch large satellites to geosynchronous orbit or perform dual launches—launching two full-size satellites with one rocket—while the other launch vehicles used for European payloads and commercial satellites—the European/Italian Vega and Russian Soyuz-2—are small and medium-lift launchers, respectively. CNES and its partners in Europe—through the Global Monitoring for Environment and Security initiative —and around the world have put in place satellites dedicated to observing the land and atmosphere, as well as to hazard and crisis management; the best-known are the SPOT satellites flying the Vegetation instrument, the Topex/Poseidon, Jason-1 and Jason-2 oceanography satellites, the Argos system and the Pleiades satellites. CNES is taking part in the Galileo navigation programme alongside the European Union and the European Space Agency, and—in a wider international context—in the Cospas-Sarsat search-and-rescue system.
The aforementioned Gallieo navigation programme, though intended for civilian navigational use, has a military purpose as well, like the similar American Global Positioning System and Russian GLONASS satellite navigational systems. In addition to Spot and the future Pleiades satellites, CNES is working for the defence community as prime contractor for the Helios photo-reconnaissance satellites. Global Monitoring for Environment and Security—a joint initiative involving the EU, ESA, national space agencies—pools space resources to monitor the environment and protect populations, though it encompasses satellite support for armed forces on border patrol, maritime security, peacekeeping missions. France's contribution to the International Space Station is giving French scientists the opportunity to perform original experiments in microgravity. CNES is studying formation flying, a technique whereby several satellites fly components of a much heavier and complex instrument in a close and tightly-controlled configuration, with satellites being as close as tens of meters apart.
CNES is studying formation flying as part of the Swedish-led PRISMA project and on its own with the Simbol-x x-ray telescope mission. CNES collaborates with other space agencies on a number of projects, including orbital telescopes like INTErnational Gamma-Ray Astrophysics Laboratory, XMM-Newton, COROT and space probes like Mars Express, Venus Express, Cassini-Huygens, Rosetta. CNES has collaborated with NASA on missions like the Earth observation satellite PARASOL and the CALIPSO environment and weather satellite, it has collaborated with the Indian Space Agency on the Megha-Tropiques Mission, studying the water cycle and how it has been impacted by climate change. CNES plays a major role in the ESA's Living Planet Programme of Earth observation satellites, having constructed the Soil Moisture and Ocean Salinity satellite. In December 2006, CNES announced that it would publish its UFO archive online by late January or mid-February. Most of the 6,000 reports have been filed by the public and airline professionals.
Jacques Arnould, an official for the French Space Agency, said that the data had accumulated over a 30-year period and that UFO sightings were reported to the Gendarmerie. In the last two decades of the 20th century, France was the only country whose government paid UFO investigators, employed by CNES's UFO section GEPAN known as SEPRA and now as GEIPAN. On March 22
Solar telescope
A solar telescope is a special purpose telescope used to observe the Sun. Solar telescopes detect light with wavelengths in, or not far outside, the visible spectrum. Obsolete names for Sun telescopes include photoheliograph. Solar telescopes need optics large enough to achieve the best possible diffraction limit but less so for the associated light-collecting power of other astronomical telescopes; however newer narrower filters and higher framerates have driven solar telescopes towards photon-starved operations. Both the European Solar Telescope as well as the Advanced Technology Solar Telescope have larger apertures not only to increase the resolution, but to increase the light-collecting power; because solar telescopes operate during the day, seeing is worse than for night-time telescopes, because the ground around the telescope is heated which causes turbulence and degrades the resolution. To alleviate this, solar telescopes are built on towers and the structures are painted white; the Dutch Open Telescope is built on an open framework to allow the wind to pass through the complete structure and provide cooling around the telescope's main mirror.
Another solar telescope-specific problem is the heat generated by the tightly-focused sunlight. For this reason, a heat stop is an integral part of the design of solar telescopes. For the upcoming ATST, the heat load is 2.5 MW/m2, with peak powers of 11.4 kW. The goal of such a heat stop is not only to survive this heat load, but to remain cool enough not to induce any additional turbulence inside the telescope's dome. Professional solar observatories may have main optical elements with long focal lengths and light paths operating in a vacuum or helium to eliminate air motion due to convection inside the telescope. However, this is not possible for apertures over 1 meter, at which the pressure difference at the entrance window of the vacuum tube becomes too large. Therefore, the EST and ATST have active cooling of the dome to minimize the temperature difference between the air inside and outside the telescope; because the Sun travels on a narrow fixed path across the sky, some solar telescopes are fixed in position, with the only moving part being a heliostat to track the Sun.
One example of this is the McMath-Pierce Solar Telescope. The Einstein Tower became operational in 1924 McMath-Pierce Solar Telescope McMath-Hulbert Observatory Swedish Vacuum Solar Telescope Swedish 1-m Solar Telescope Richard B. Dunn Solar Telescope Mount Wilson Observatory Dutch Open Telescope The Teide Observatory hosts multiple solar telescopes, including the 70 cm Vacuum Tower Telescope and the 1.5 m GREGOR Solar Telescope. Advanced Technology Solar Telescope, a planned telescope with 4m aperture. European Solar Telescope, a future 4-meter class aperture telescope. National Large Solar Telescope, is a Gregorian multi-purpose open telescope proposed to be built and Installed in India and aims to study the Sun's microscopic structure. WISPR, is double solar telescope on the Parker Solar Probe designed to image the corona close to the Sun from space Most solar observatories observe optically at visible, UV, near infrared wavelengths, but other solar phenomena can be observed — albeit not from the Earth's surface due to the absorption of the atmosphere: Solar X-ray astronomy, observations of the Sun in x-rays Multi-spectral solar telescope array, a rocket launched payload of UV telescopes in the 1990s Leoncito Astronomical Complex operated a submillimeter wavelength solar telescope.
The Radio Solar Telescope Network is a network of solar observatories maintained and operated by the U. S. Air Force Weather Agency. CERN Axion Solar Telescope, looks for solar axions in the early 2000s In the field of amateur astronomy there are many methods used to observe the Sun. Amateurs use everything from simple systems to project the Sun on a piece of white paper, light blocking filters, Herschel wedges which redirect 95% of the light away from the eyepiece, up to hydrogen-alpha filter systems and home built spectrohelioscopes. In contrast to professional telescopes, amateur solar telescopes are much smaller. List of solar telescopes List of telescope types Heliostat Solar telescopes, Wolfgang Schmidt, Scholarpedia,3:4333. Doi:10.4249/scholarpedia.4333 CSIRO Solar Heliograph part 2 Solar Gallery of an amateur astronomer Solar Gallery of the Hong Kong Astronomical Society Lawrence, Pete. "Solar Observing". Deep Sky Videos. Brady Haran
Observatory
An observatory is a location used for observing terrestrial or celestial events. Astronomy, climatology/meteorology, geophysical and volcanology are examples of disciplines for which observatories have been constructed. Observatories were as simple as containing an astronomical sextant or Stonehenge. Astronomical observatories are divided into four categories: space-based, ground-based, underground-based. Ground-based observatories, located on the surface of Earth, are used to make observations in the radio and visible light portions of the electromagnetic spectrum. Most optical telescopes are housed within a dome or similar structure, to protect the delicate instruments from the elements. Telescope domes have a slit or other opening in the roof that can be opened during observing, closed when the telescope is not in use. In most cases, the entire upper portion of the telescope dome can be rotated to allow the instrument to observe different sections of the night sky. Radio telescopes do not have domes.
For optical telescopes, most ground-based observatories are located far from major centers of population, to avoid the effects of light pollution. The ideal locations for modern observatories are sites that have dark skies, a large percentage of clear nights per year, dry air, are at high elevations. At high elevations, the Earth's atmosphere is thinner, thereby minimizing the effects of atmospheric turbulence and resulting in better astronomical "seeing". Sites that meet the above criteria for modern observatories include the southwestern United States, Canary Islands, the Andes, high mountains in Mexico such as Sierra Negra. A newly emerging site which should be added to this list is Mount Gargash. With an elevation of 3600 m above sea level, it is the home to the Iranian National Observatory and its 3.4m INO340 telescope. Major optical observatories include Mauna Kea Observatory and Kitt Peak National Observatory in the US, Roque de los Muchachos Observatory and Calar Alto Observatory in Spain, Paranal Observatory in Chile.
Specific research study performed in 2009 shows that the best possible location for ground-based observatory on Earth is Ridge A — a place in the central part of Eastern Antarctica. This location provides the least atmospheric disturbances and best visibility. Beginning in 1930s, radio telescopes have been built for use in the field of radio astronomy to observe the Universe in the radio portion of the electromagnetic spectrum; such an instrument, or collection of instruments, with supporting facilities such as control centres, visitor housing, data reduction centers, and/or maintenance facilities are called radio observatories. Radio observatories are located far from major population centers to avoid electromagnetic interference from radio, TV, other EMI emitting devices, but unlike optical observatories, radio observatories can be placed in valleys for further EMI shielding; some of the world's major radio observatories include the Socorro, in New Mexico, United States, Jodrell Bank in the UK, Arecibo in Puerto Rico, Parkes in New South Wales and Chajnantor in Chile.
Since the mid-20th century, a number of astronomical observatories have been constructed at high altitudes, above 4,000–5,000 m. The largest and most notable of these is the Mauna Kea Observatory, located near the summit of a 4,205 m volcano in Hawaiʻi; the Chacaltaya Astrophysical Observatory in Bolivia, at 5,230 m, was the world's highest permanent astronomical observatory from the time of its construction during the 1940s until 2009. It has now been surpassed by the new University of Tokyo Atacama Observatory, an optical-infrared telescope on a remote 5,640 m mountaintop in the Atacama Desert of Chile; the oldest proto-observatories, in the sense of a private observation post, Wurdi Youang, Australia Zorats Karer, Armenia Loughcrew, Ireland Newgrange, Ireland Stonehenge, Great Britain Quito Astronomical Observatory, located 12 minutes south of the Equator in Quito, Ecuador. Chankillo, Peru El Caracol, Mexico Abu Simbel, Egypt Kokino, Republic of Macedonia Observatory at Rhodes, Greece Goseck circle, Germany Ujjain, India Arkaim, Russia Cheomseongdae, South Korea Angkor Wat, CambodiaThe oldest true observatories, in the sense of a specialized research institute, include: 825 AD: Al-Shammisiyyah observatory, Iraq 869: Mahodayapuram Observatory, India 1259: Maragheh observatory, Iran 1276: Gaocheng Astronomical Observatory, China 1420: Ulugh Beg Observatory, Uzbekistan 1442: Beijing Ancient Observatory, China 1577: Constantinople Observatory of Taqi ad-Din, Turkey 1580: Uraniborg, Denmark 1581: Stjerneborg, Denmark 1642: Panzano Observatory, Italy 1642: Round Tower, Denmark 1633: Leiden Observatory, Netherlands 1667: Paris Observatory, France 1675: Royal Greenwich Observatory, England 1695: Sukharev Tower, Russia 1711: Berlin Observatory, Germany 1724: Jantar Mantar, India 1753: Stockholm Observatory, Sweden 1753: Vilnius University Observatory, Lithuania 1753: Navy Royal Institute and Observatory, Spain 1759: Trieste Observatory, Italy 1757: Macfarlane Observatory, Scotland 1759: Turin Observatory, Italy 1764: Brera Astronomical Observatory, Italy 1765: Mohr Observatory, Indonesia 1774: Vatican Observatory, Vatican 1785: Dunsink Observatory, Ireland 1786: Madras Observatory, India 1789: Armagh Observatory, Northern Ireland 1790: Real Observatorio de Madrid, Spain, 1803: National Astronomical Observatory, Bogotá, Colombia.
1811: Tartu Old Observatory, Estonia 1812: Astronomical Observatory of Capodimonte, Italy 1830/1842: Depot of Charts & Instruments
Brian Schmidt
Brian Paul Schmidt is the Vice-Chancellor of the Australian National University. He was a Distinguished Professor, Australian Research Council Laureate Fellow and astrophysicist at the University's Mount Stromlo Observatory and Research School of Astronomy and Astrophysics, he is known for his research in using supernovae as cosmological probes. He holds an Australia Research Council Federation Fellowship and was elected a Fellow of the Royal Society in 2012. Schmidt shared both the 2006 Shaw Prize in Astronomy and the 2011 Nobel Prize in Physics with Saul Perlmutter and Adam Riess for providing evidence that the expansion of the universe is accelerating, making him the only Montana-born Nobel laureate. Schmidt, an only child, was born on 24 February 1967, in Missoula, where his father Dana C. Schmidt was a fisheries biologist; when he was 13, his family relocated to Alaska. Schmidt attended Bartlett High School in Anchorage and graduated in 1985, he has said that he wanted to be a meteorologist "since I was about five-years-old...
I did some work at the USA National Weather Service up in Anchorage and didn't enjoy it much. It was less scientific, not as exciting as I thought it would be—there was a lot of routine, but I guess I was just a little naive about what being a meteorologist meant." His decision to study astronomy, which he had seen as "a minor pastime", was made just before he enrolled at university. He was not committed: he said "I'll do astronomy and change into something else later", just never made that change, he graduated with a BS and BS from the University of Arizona in 1989. He received his AM in 1992 and PhD in 1993 from Harvard University. Schmidt's PhD thesis was supervised by Robert Kirshner and used Type II Supernovae to measure the Hubble Constant. While at Harvard, he met his future wife, the Australian Jennifer M. Gordon, a PhD student in economics. In 1994, they moved to Australia. Schmidt was a postdoctoral research Fellow at the Harvard-Smithsonian Center for Astrophysics before moving on to the ANU's Mount Stromlo Observatory in 1995.
In 1994, Schmidt and Nicholas B. Suntzeff formed the High-Z Supernova Search Team to measure the expected deceleration of the universe and the deceleration parameter using distances to Type Ia supernovae. In 1995, the HZT at a meeting at the Harvard-Smithsonian Center for Astrophysics elected Schmidt as the overall leader of the HZT. Schmidt led the team from Australia and in 1998 in the HZT paper with first author Adam Riess the first evidence was presented that the universe's expansion rate is not decelerating; the team's observations were contrary to the then-current models, which predicted that the expansion of the universe should be slowing down, when the preliminary results emerged Schmidt assumed it was an error and he spent the next six weeks trying to find the mistake. But there was no mistake: contrary to expectations, by monitoring the brightness and measuring the redshift of the supernovae, they discovered that these billion-year old exploding stars and their galaxies were accelerating away from our reference frame.
This result was found nearly by the Supernova Cosmology Project, led by Saul Perlmutter. The corroborating evidence between the two competing studies led to the acceptance of the accelerating universe theory and initiated new research to understand the nature of the universe, such as the existence of dark energy; the discovery of the accelerating universe was named'Breakthrough of the Year' by Science in 1998, Schmidt was jointly awarded the 2011 Nobel Prize in Physics along with Riess and Perlmutter for their groundbreaking work. Schmidt is leading the SkyMapper telescope Project and the associated Southern Sky Survey, which will encompass billions of individual objects, enabling the team to pick out the most unusual objects. In 2014 they announced the discovery of the first star which did not contain any iron, indicating that it is a primitive star formed during the first rush of star formation following the Big Bang, he is the chairman of the board of directors of Astronomy Australia Limited, he serves on the management committee of the ARC Centre of Excellence for All-Sky Astrophysics.
In July 2012 Schmidt was given a three-year appointment to sit on the Questacon Advisory Council. As of March 2017, Schmidt serves as a member of the Bulletin of the Atomic Scientists' Board of Sponsors. On 24 June 2015 it was announced Schmidt would replace Ian Young as the 12th Vice-Chancellor of the Australian National University, to commence his tenure on 1 January 2016; the Chancellor of the ANU, Professor Gareth Evans, said, "Brian Schmidt is superbly placed to deliver on the ambition of ANU founders – to permanently secure our position among the great universities of the world, as a crucial contributor to the nation... We had a stellar field of international and Australian candidates, have chosen an inspirational leader.... Brian's vision, global stature and communication skills are going to take our national university to places it has never been before." The publicity that came with winning the Nobel Prize has given Schmidt the opportunity to help the public understand why science is important to society, to champion associated causes.
Public education One of his first acts after winning the Nobel Prize was to donate $100,000 out of his prize money to the PrimaryConnections program, an initiative of the Australian Academy of Science that assists primary school teachers. He has continued to press for improvements to the public school system in the sciences and mathematical literacy (numeracy
Anglo-Australian Telescope
The Anglo-Australian Telescope is a 3.9-metre equatorially mounted telescope operated by the Australian Astronomical Observatory and situated at the Siding Spring Observatory, Australia at an altitude of a little over 1,100 m. In 2009, the telescope was ranked as the fifth highest-impact of the world's optical telescopes. In 2001–2003, it was considered the most scientifically productive 4-metre-class optical telescope in the world based on scientific publications using data from the telescope; the telescope was commissioned in 1974 with a view to allowing high quality observations of the sky from the southern hemisphere. At the time, most major telescopes were located in the northern hemisphere, leaving the southern skies poorly observed, it was the largest telescope in the Southern hemisphere from 1974-1976 a close second to the Victor M. Blanco Telescope from 1976 until 1998, when the first ESO Very Large Telescope was opened; the AAT was credited with stimulating a resurgence in British optical astronomy.
It was built by the United Kingdom in partnership with Australia but has been funded by Australia since 2010. Observing time is available to astronomers worldwide; the AAT was one of the last large telescopes built with an equatorial mount. More recent large telescopes have instead adopted the more compact and mechanically stable altazimuth mount; the AAT was, one of the first telescopes to be computer-controlled, set new standards for pointing and tracking accuracy. British astronomer Richard van der Riet Woolley pushed for a large optical telescope for the southern hemisphere in 1959. In 1965, Macfarlane Burnet, president of the Australian Academy of Science, wrote to the federal education minister John Gorton inviting the federal government to support a joint British-Australian telescope project. Gorton was supportive, nominated the Australian National University and CSIRO as Australia's representatives in the joint venture. Gorton brought the proposal before cabinet in April 1967, which endorsed the scheme and agreed to contribute half the capital and running costs.
An agreement with the British was finalised a few weeks and a Joint Policy Committee started work on construction planning in August 1967. It took until September 1969 for plans to be finalised; the agreement committed the specification to a telescope design based on the American Kitt Peak telescope until its deficiencies were known. Both the horseshoe mount and the gearing system needed improvements. Although the revised gear system was more expensive it was more accurate, lending itself well to future applications; the mirror blank was made by Owens-Illinois in Ohio. It was transported to Newcastle, England where Sir Howard Grubb, Parsons and Co took two years to grind and polish the mirror's surface. Mitsubishi Electric built the mount, constructed by August 1973. First light occurred on 27 April 1974; the telescope was opened by Prince Charles on 16 October 1974. The telescope is housed within a seven-story, concrete building topped with a 36m diameter rotating steel dome, it was designed to withstand the high winds prevailing at that location.
The slit is narrow. The dome is required to move with the telescope to avoid obstruction; the top of the dome is 50m above ground level. The telescope tube structure is supported inside a massive 12m diameter horseshoe, which rotates around the polar axis for tracking the sky. Total moving mass is 260 tonnes; the telescope has various foci for flexible instrumentation: there were three top-end rings which can be exchanged using the dome crane during the daytime. One was for f/3.3 prime-focus, with corrector lenses and a cage for a human observer taking photographs. A fourth top-end was built in the 1990s to give a 2-degree field of view at prime focus, with 400 optical fibres feeding the 2dF instrument and its enhancements AAOmega and HERMES; the AAT is equipped with a number of instruments, including: The Two Degree Field facility, a robotic optical fibre positioner for obtaining spectroscopy of up to 400 objects over a 2° field of view simultaneously. The University College London Échelle Spectrograph, a high-resolution optical spectrograph, used to discover many extrasolar planets.
IRIS2, a wide-field infrared camera and spectrograph. The newest instrument, HERMES, was commissioned in 2015, it is a new high-resolution spectrograph to be used with the 2dF fibre positioner. HERMES is being used for the'Galactic Archaeology with Hermes' Survey, which aims to reconstruct the history of our galaxy's formation from precise multi-element abundances of 1 million stars derived from HERMES spectra. List of largest optical reflecting telescopes Official website Online catalogue of building project papers
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