In many fields of mathematics and physics, almost all scientific papers are self-archived on the arXiv repository. Begun on August 14,1991, arXiv. org passed the half-million article milestone on October 3,2008, by 2014 the submission rate had grown to more than 8,000 per month. The arXiv was made possible by the low-bandwidth TeX file format, around 1990, Joanne Cohn began emailing physics preprints to colleagues as TeX files, but the number of papers being sent soon filled mailboxes to capacity. Additional modes of access were added, FTP in 1991, Gopher in 1992. The term e-print was quickly adopted to describe the articles and its original domain name was xxx. lanl. gov. Due to LANLs lack of interest in the rapidly expanding technology, in 1999 Ginsparg changed institutions to Cornell University and it is now hosted principally by Cornell, with 8 mirrors around the world. Its existence was one of the factors that led to the current movement in scientific publishing known as open access. Mathematicians and scientists regularly upload their papers to arXiv.
org for worldwide access, Ginsparg was awarded a MacArthur Fellowship in 2002 for his establishment of arXiv. The annual budget for arXiv is approximately $826,000 for 2013 to 2017, funded jointly by Cornell University Library, annual donations were envisaged to vary in size between $2,300 to $4,000, based on each institution’s usage. As of 14 January 2014,174 institutions have pledged support for the period 2013–2017 on this basis, in September 2011, Cornell University Library took overall administrative and financial responsibility for arXivs operation and development. Ginsparg was quoted in the Chronicle of Higher Education as saying it was supposed to be a three-hour tour, Ginsparg remains on the arXiv Scientific Advisory Board and on the arXiv Physics Advisory Committee. The lists of moderators for many sections of the arXiv are publicly available, additionally, an endorsement system was introduced in 2004 as part of an effort to ensure content that is relevant and of interest to current research in the specified disciplines.
Under the system, for categories that use it, an author must be endorsed by an established arXiv author before being allowed to submit papers to those categories. Endorsers are not asked to review the paper for errors, new authors from recognized academic institutions generally receive automatic endorsement, which in practice means that they do not need to deal with the endorsement system at all. However, the endorsement system has attracted criticism for allegedly restricting scientific inquiry, perelman appears content to forgo the traditional peer-reviewed journal process, stating, If anybody is interested in my way of solving the problem, its all there – let them go and read about it. The arXiv generally re-classifies these works, e. g. in General mathematics, papers can be submitted in any of several formats, including LaTeX, and PDF printed from a word processor other than TeX or LaTeX. The submission is rejected by the software if generating the final PDF file fails, if any image file is too large.
ArXiv now allows one to store and modify an incomplete submission, the time stamp on the article is set when the submission is finalized
It is similar to the asteroid belt, but it is far larger—20 times as wide and 20 to 200 times as massive. Like the asteroid belt, it consists mainly of small bodies, although many asteroids are composed primarily of rock and metal, most Kuiper belt objects are composed largely of frozen volatiles, such as methane and water. The Kuiper belt is home to three officially recognized dwarf planets, Pluto and Makemake, some of the Solar Systems moons, such as Neptunes Triton and Saturns Phoebe, are thought to have originated in the region. The Kuiper belt was named after Dutch-American astronomer Gerard Kuiper, though he did not actually predict its existence, in 1992,1992 QB1 was discovered, the first Kuiper belt object since Pluto. Since its discovery, the number of known KBOs has increased to over a thousand, the Kuiper belt should not be confused with the theorized Oort cloud, which is a thousand times more distant and is mostly spherical. The objects within the Kuiper belt, together with the members of the scattered disc, Pluto is the largest and most-massive member of the Kuiper belt and the largest and the second-most-massive known TNO, surpassed only by Eris in the scattered disc.
Originally considered a planet, Plutos status as part of the Kuiper belt caused it to be reclassified as a planet in 2006. It is compositionally similar to other objects of the Kuiper belt, and its orbital period is characteristic of a class of KBOs, known as plutinos. After the discovery of Pluto in 1930, many speculated that it not be alone. The region now called the Kuiper belt was hypothesized in various forms for decades and it was only in 1992 that the first direct evidence for its existence was found. The number and variety of speculations on the nature of the Kuiper belt have led to continued uncertainty as to who deserves credit for first proposing it. The first astronomer to suggest the existence of a population was Frederick C. That same year, astronomer Armin O. Leuschner suggested that Pluto may be one of many long-period planetary objects yet to be discovered. Kuiper was operating on the common in his time that Pluto was the size of Earth and had therefore scattered these bodies out toward the Oort cloud or out of the Solar System.
Were Kuipers hypothesis correct, there would not be a Kuiper belt today, the hypothesis took many other forms in the following decades. Cameron postulated the existence of a mass of small material on the outskirts of the solar system. Observation, ruled out this hypothesis, in 1977, Charles Kowal discovered 2060 Chiron, an icy planetoid with an orbit between Saturn and Uranus. He used a blink comparator, the device that had allowed Clyde Tombaugh to discover Pluto nearly 50 years before
Neptune trojans are bodies in orbit around the Sun that orbit near one of the stable Lagrangian points of Neptune. They therefore have approximately the same period as Neptune and follow roughly the same orbital path. Seventeen Neptune trojans are known, of which thirteen orbit near the Sun–Neptune L4 Lagrangian point 60° ahead of Neptune. The Neptune trojans are termed trojans by analogy with the Jupiter trojans and it is suspected that large Neptune trojans could outnumber Jupiter trojans by an order of magnitude. In 2010, the discovery of the first known L5 Neptune trojan,2008 LC18, was announced, Neptunes trailing L5 region is currently very difficult to observe because it is along the line-of-sight to the center of the Milky Way, an area of the sky crowded with stars. However, New Horizons may not have had sufficient downlink bandwidth, in 2001, the first Neptune trojan was discovered,2001 QR322, near Neptunes L4 region, and with it the fifth known populated stable reservoir of small bodies in the Solar System.
In 2005, the discovery of the high-inclination trojan 2005 TN53 has indicated that the Neptune trojans populate thick clouds, on August 12,2010, the first L5 trojan,2008 LC18, was announced. It was discovered by a survey that scanned regions where the light from the stars near the Galactic Center is obscured by dust clouds. This suggests that large L5 trojans are as common as large L4 trojans, to within uncertainty and it would have been possible for the New Horizons spacecraft to investigate L5 Neptune trojans discovered by 2014, when it passed through this region of space en route to Pluto. Some of the patches where the light from the Galactic Center is obscured by dust clouds are along New Horizonss flight path, allowing detection of objects that the spacecraft could image. 2011 HM102, the highest-inclination Neptune trojan known, was just bright enough for New Horizons to observe it in end-2013 at a distance of 1.2 AU. However, New Horizons may not have had sufficient downlink bandwidth, the orbits of Neptune trojans are highly stable, Neptune may have retained up to 50% of the original post-migration trojan population over the age of the Solar System.
Neptunes L5 can host stable trojans equally well as its L4, Neptune trojans can librate up to 30° from their associated Lagrangian points with a 10, 000-year period. Neptune trojans that escape enter orbits similar to centaurs, although Neptune cannot currently capture stable trojans, roughly 2. 8% of the centaurs within 34 AU are predicted to be Neptune co-orbitals. Of these, 54% would be in horseshoe orbits, 10% would be quasi-satellites, the unexpected high-inclination trojans are the key to understanding the origin and evolution of the population as a whole. The existence of high-inclination Neptune trojans points to a capture during planetary migration instead of in situ or collisional formation. The estimated equal number of large L5 and L4 trojans indicates that there was no gas drag during capture, the capture of Neptune trojans during a migration of the planets occurs via process similar to the chaotic capture of Jupiter trojans in the Nice model. When Uranus and Neptune are near but not in a mean-motion resonance the period at which the locations where Uranus passes Neptune circulate can resonate with the periods of Neptune trojans
In astronomy, a plutino is a trans-Neptunian object in 2,3 mean-motion resonance with Neptune. For every 2 orbits that a plutino makes, Neptune orbits 3 times, the term plutino derived from the dwarf planet Pluto, the largest and the first plutino discovered. The term does not imply common physical characteristics, Plutinos are named after mythological creatures associated with the underworld. Plutinos form the part of the Kuiper belt and represent about a quarter of the known Kuiper belt objects. Plutinos are the largest class of the resonant trans-Neptunian objects, aside from Pluto itself, the first plutino,1993 RO, was discovered on September 16,1993. It is thought that objects that are currently in mean orbital resonances with Neptune initially followed independent heliocentric paths. As Neptune migrated outward early in the Solar Systems history, the bodies it approached would have been scattered, during this process, the 3,2 resonance is the strongest and most stable among all resonances.
This is the reason it contains the largest number of bodies. The orbital periods of plutinos cluster around 247.3 years, the gravitational influence of Pluto is usually neglected given its small mass. However, the width is very narrow and only a few times larger than Pluto’s Hill sphere. Consequently, depending on the eccentricity, some plutinos will be driven out of the resonance by interactions with Pluto. Numerical simulations suggest that the orbits of plutinos with an eccentricity 10%–30% smaller or larger than that of Pluto are not stable over Ga timescales, the plutinos brighter than HV=6 include, David Jewitt on Plutinos Minor Planet Center, List of TNOs MPC List of Distant Minor Planets
National Optical Astronomy Observatory
The National Optical Astronomy Observatory is the United States national observatory for ground based nighttime ultraviolet-optical-infrared astronomy. The National Science Foundation funds NOAO to provide forefront astronomical research facilities for US astronomers, professional astronomers from any country in the world may apply to use the telescopes operated by NOAO under the NSFs open skies policy. Astronomers submit proposals for review to gain access to the telescopes which are scheduled every night of the year for observations. The combination of open access and the merit based science proposal process makes NOAO unique in the world. The NOAO headquarters are located in Tucson and are co-located with the headquarters of the National Solar Observatory, the NOAO is operated by the Association of Universities for Research in Astronomy, under a cooperative agreement with the NSF. NOAO operates world class research telescopes in both the northern and southern hemispheres and these telescopes are located at Kitt Peak and Cerro Tololo in the US and Chile, respectively.
Complemented with similar instruments, the two sites allow US astronomers to make observations over the entire sky. Instrumentation includes optical to near infrared wavelength cameras and spectrometers, CTIO has a base and office facility in the seaside town of La Serena, Chile. The CTIO telescopes are located some 70 km inland in the foothills of the Chilean Andes, access to the observatory is made through the picturesque Elqui Valley. The Blanco 4m played the role in discovery of Dark Energy. The Blanco began hosting a new 3-degree field of view called the Dark Energy Camera, known as DECam. This camera is being built at Fermilab in Chicago, USA, CTIO operates, and is a partner in the 4. 1m Southern Astrophysical Research Telescope. SOAR concentrates on high resolution observations and will soon deploy an adaptive optics module to help support such observations. KPNO is located near Tucson, AZ, USA, the mountain, Kitt Peak, is part of the tribal lands of the Native American people the Tohono Oodham.
The mountain has been leased from the Tohono Oodham since 1958, the native name for the mountain is loligam which means manzanita. The observatory was established in 1958, and its largest telescope, a new wide field imager working at near infrared wavelengths has been deployed to advance studies of galactic star formation and the structure and evolution of galaxies. NOAO manages US participation in the international Gemini Observatory, Gemini is a partnership of Argentina, Brazil, the United Kingdom, and the United States. The US holds a 50% share of the project which provides public access time on each of Geminis two 8m telescopes, one telescope is located near CTIO in Chile, and the other is located on the island of Hawaii
(87269) 2000 OO67
2000 OO67 is a small trans-Neptunian object discovered by the Deep Ecliptic Survey in 2000. It is remarkable for its eccentric orbit. At aphelion it is over 1,000 AU from the Sun and, with a perihelion of 21 AU, some astronomers list it as a centaur. 2000 OO67 came to perihelion in April 2005, both 2000 OO67 and 2006 SQ372 take longer than Sedna to orbit the Sun using either heliocentric coordinates or barycentric coordinates
Classical Kuiper belt object
A classical Kuiper belt object, called a cubewano, is a low-eccentricity Kuiper belt object that orbits beyond Neptune and is not controlled by an orbital resonance with Neptune. Cubewanos have orbits with semi-major axes in the 40–50 AU range and, unlike Pluto and that is, they have low-eccentricity and sometimes low-inclination orbits like the classical planets. The name cubewano derives from the first trans-Neptunian object found after Pluto, similar objects found were often called QB1-os, or cubewanos, after this object, though the term classical is much more frequently used in the scientific literature. Most cubewanos are found between the 2,3 orbital resonance with Neptune and the 1,2 resonance,50000 Quaoar, for example, has a near-circular orbit close to the ecliptic. Plutinos, on the hand, have more eccentric orbits bringing some of them closer to the Sun than Neptune. The majority of objects, have low inclinations and near-circular orbits, a smaller population is characterised by highly inclined, more eccentric orbits.
The Deep Ecliptic Survey reports the distributions of the two populations, one with the inclination centered at 4. 6° and another with inclinations extending beyond 30°, the vast majority of KBOs have inclinations of less than 5° and eccentricities of less than 0.1. The hot and cold populations are different, more than 30% of all cubewanos are in low inclination. The parameters of the orbits are more evenly distributed, with a local maximum in moderate eccentricities in 0. 15–0.2 range. See the comparison with scattered disk objects, when orbital inclinations are compared, hot cubewanos can be easily distinguished by their higher inclinations, as the plutinos typically keep orbits below 20°. In addition to the orbital characteristics, the two populations display different physical characteristics. The difference in colour between the red cold population and more heterogeneous hot population was observed as early as in 2002, another difference between the low-inclination and high-inclination classical objects is the observed number of binary objects.
Binaries are quite common on low-inclination orbits and are typically similar-brightness systems, binaries are less common on high-inclination orbits and their components typically differ in brightness. There is no definition of cubewano or classical KBO. However, the terms are used to refer to objects free from significant perturbation from Neptune. The Minor Planet Center and the Deep Ecliptic Survey do not list cubewanos using the same criteria, many TNOs classified as cubewanos by the MPC are classified as ScatNear by the DES. Dwarf planet Makemake is such a borderline classical cubewano/scatnear object,2002 KX14 may be an inner cubewano near the plutinos. Furthermore, there is evidence that the Kuiper belt has an edge, in that an apparent lack of objects beyond 47–49 AU was suspected as early as 1998
It is very likely to be a dwarf planet, although the IAU has not officially classified it as such. Light-curve-amplitude analysis shows only small deviations, which suggests that Ixion is a spheroid with small albedo spots and it has a diameter of approximately 650 km, making it about the fifth-largest plutino. It is moderately red in light and has a surface made of a mixture of tholin. It was discovered on May 22,2001 by the Cerro Tololo Inter-American Observatory and it is named after Ixion, a figure from Greek mythology. More recent estimates suggest that Ixion has an albedo and is smaller than Ceres. Observations of Ixion by Herschel Space Telescope and Spitzer Space Telescope in the part of the spectrum revealed that its size is about 620 km. Ixion is moderately red in the visible light and it has a higher albedo than the mid-sized red cubewanos. There may be a feature at the wavelength of 0.8 μm in its spectrum. In the near-infrared the spectrum of Ixion is flat and featureless, water ice absorption bands at 1.5 and 2 μm are absent.
This is in contrast to Varuna, which has a red slope in the near-infrared as well as prominent water absorption bands. The Very Large Telescope has checked Ixion for cometary activity, Ixion is currently about 41 AU from the Sun, and it is possible that Ixion could develop a coma or temporary atmosphere when it is closer to perihelion. Ixion and Pluto follow similar but differently oriented orbits, Ixion’s perihelion is below the ecliptic whereas Plutos is above it, uncharacteristically for bodies locked in resonance with Neptune, Ixion approaches Pluto with less than 20 degrees of angular separation. Ixion is currently below the ecliptic and will reach its perihelion in 2070, Pluto has passed its perihelion and is descending toward the ecliptic. Ixions orbital period is almost 250 Earth years, about 0. 5% larger than Plutos, Ixion does demonstrate some regular changes in brightness, which are thought to be caused by its rotation. As of 2010, the period of Ixion remains undetermined
A trans-Neptunian object is any minor planet in the Solar System that orbits the Sun at a greater average distance than Neptune,30 astronomical units. Twelve minor planets with a semi-major axis greater than 150 AU and perihelion greater than 30 AU are known, the first trans-Neptunian object to be discovered was Pluto in 1930. It took until 1992 to discover a second trans-Neptunian object orbiting the Sun directly,1992 QB1, as of February 2017 over 2,300 trans-Neptunian objects appear on the Minor Planet Centers List of Transneptunian Objects. Of these TNOs,2,000 have a perihelion farther out than Neptune, as of November 2016,242 of these have their orbits well-enough determined that they have been given a permanent minor planet designation. The largest known object is Pluto, followed by Eris,2007 OR10, Makemake. The Kuiper belt, scattered disk, and Oort cloud are three divisions of this volume of space, though treatments vary and a few objects such as Sedna do not fit easily into any division.
The orbit of each of the planets is slightly affected by the influences of the other planets. Discrepancies in the early 1900s between the observed and expected orbits of Uranus and Neptune suggested that there were one or more additional planets beyond Neptune, the search for these led to the discovery of Pluto in February 1930, which was too small to explain the discrepancies. Revised estimates of Neptunes mass from the Voyager 2 flyby in 1989 showed that the problem was spurious, Pluto was easiest to find because it has the highest apparent magnitude of all known trans-Neptunian objects. It has an inclination to the ecliptic than most other large TNOs. After Plutos discovery, American astronomer Clyde Tombaugh continued searching for years for similar objects. For a long time, no one searched for other TNOs as it was believed that Pluto. Only after the 1992 discovery of a second TNO,1992 QB1, a broad strip of the sky around the ecliptic was photographed and digitally evaluated for slowly moving objects.
Hundreds of TNOs were found, with diameters in the range of 50 to 2,500 kilometers and Eris were eventually classified as dwarf planets by the International Astronomical Union. Kuiper belt objects are classified into the following two groups, Resonant objects are locked in an orbital resonance with Neptune. Objects with a 1,2 resonance are called twotinos, and objects with a 2,3 resonance are called plutinos, after their most prominent member, classical Kuiper belt objects have no such resonance, moving on almost circular orbits, unperturbed by Neptune. Examples are 1992 QB1,50000 Quaoar and Makemake, the scattered disc contains objects farther from the Sun, usually with very irregular orbits. A typical example is the most massive known TNO, scattered-extended —Scattered-extended objects have a Tisserand parameter greater than 3 and have a time-averaged eccentricity greater than 0
An astronomical survey is a general map or image of a region of the sky which lacks a specific observational target. Alternatively, a survey may comprise a set of many images or spectra of objects which share a common type or feature. Surveys have generally performed as part of the production of an astronomical catalog. In some cases, an interested in a particular object will find that survey images are sufficient to make telescope time entirely unnecessary. Surveys help astronomers obtain observation time on larger, more powerful telescopes, if the astronomer can show a telescope scheduling committee that previous observations support his or her hypothesis, he or she is more likely to be given a chance to make more detailed observations. The wide scope of surveys makes them ideal for astronomers searching for moving objects such as asteroids. An astronomer can compare existing survey images to current observations to locate targets which are in motion, images of the same object taken by different surveys can be compared to detect transient events such as variable stars.
It began in 1977 to 1982 from 1985 to 1995.3,4.7,12, the telescope is over a thousand times as sensitive as previous infrared surveys. The initial survey, consisting of each sky position imaged at least eight times, was completed by July 2010, 1997–2002 Ohio Sky Survey – Over 19,000 radio sources at 1415 MHz. NVSS – Survey at 1.4 GHz mapping the sky north of −40 deg FIRST – Survey to look for faint radio sources at twenty cms, PALFA Survey – On-going 1.4 GHz survey for radio pulsars using the Arecibo Observatory. 2008–present, the goal for the lifetime is 10 years. The resulting dataset aims to be a resource for studying the physics of the galaxy population. GOODS – The Great Observatories Origins Deep Survey, COSMOS – The Cosmic Evolution Survey. Atlas 3d Survey – sample of 260 galaxies for the Astrophysics project, timeline of astronomical maps and surveys