Scutum is a small constellation introduced in the seventeenth century. Its name is Latin for shield. Scutum was named in 1684 by Polish astronomer Johannes Hevelius, who named it Scutum Sobiescianum to commemorate the victory of the Christian forces led by Polish King John III Sobieski in the Battle of Vienna in 1683; the name was shortened to Scutum. Five bright stars of Scutum were known as 1, 6, 2, 3, 9 Aquilae respectively. Coincidentally, the Chinese associated these stars with battle armor, incorporating them into the larger asterism known as Tien Pien, i.e. the Heavenly Casque. Scutum is not a bright constellation, with the brightest star, Alpha Scuti, at magnitude 3.85. But some stars are notable in the constellation. Beta Scuti is the second brightest at magnitude 4.22, followed by Delta Scuti at magnitude 4.72. Beta Scuti is a binary system, with the primary with a spectral type similar to the Sun, although it is 1,270 times brighter. Delta Scuti is a bluish white giant star, now coming at the direction of the Solar System.
Within 1.3 million years it will come as close to 10 light years from Earth, will be much brighter than Sirius by that time. UY Scuti is a red supergiant pulsating variable star and is one of the largest stars known with a radius over 1,000 times that of the Sun. Although not a large constellation, Scutum contains several open clusters, as well as a globular cluster and a planetary nebula; the two best known deep sky objects in Scutum are M11 and the open cluster M26. The globular cluster NGC 6712 and the planetary nebula IC 1295 can be found in the eastern part of the constellation, only 24 arcminutes apart; the most prominent open cluster in Scutum is the Wild Duck Cluster, M11. It was named by William Henry Smyth in 1844 for its resemblance in the eyepiece to a flock of ducks in flight; the cluster, 6200 light-years from Earth and 20 light-years in diameter, contains 3000 stars, making it a rich cluster. It is 220 million years old; the space probe. It will not be nearing the closest star in this constellation for over a million years at present speed, by which time its batteries will be long dead.
Taurus Poniatovii - a constellation created by the Polish astronomer Marcin Odlanicki Poczobutt in 1777 to honor King of Poland Stanisław August Poniatowski. Ian Ridpath and Wil Tirion. Stars and Planets Guide, London. ISBN 978-0-00-823927-5. Princeton University Press, Princeton. ISBN 978-0-69-117788-5; the Deep Photographic Guide to the Constellations: Scutum Star Tales – Scutum
Westerbork Synthesis Radio Telescope
The Westerbork Synthesis Radio Telescope is an aperture synthesis interferometer near World War II Nazi detention and transit camp Westerbork, north of the village of Westerbork, Midden-Drenthe, in the northeastern Netherlands. It consists of a linear array of 14 antennas with a diameter of 25 metres arranged on a 2.7 km East-West line. It has a similar arrangement to other radio telescopes such as the One-Mile Telescope, Australia Telescope Compact Array and the Ryle Telescope, its Equatorial mount is what sets it apart from most other radio telescopes, most of which have an Altazimuth mount. This makes it useful for specific types of science, like polarized emission research as the detectors maintain a constant orientation on the sky during an observation. Ten of the telescopes are on fixed mountings while the remaining four dishes are movable along two rail tracks; the telescope was completed in 1970 and underwent a major upgrade between 1995-2000. The telescopes in the array can operate at several frequencies between 120 MHz and 8.3 GHz with an instantaneous bandwidth of 120 MHz and 8092 line spectral resolution.
The WSRT is combined with other telescopes around the world to perform very-long-baseline interferometry observations, being part of the European VLBI Network. The telescope is operated by the Dutch foundation for astronomy research; as of writing, the WSRT is undergoing a major upgrade started in 2013 as part of the APERTIF project, where the current detectors are replaced with focal-plane arrays. This will allow a 25x larger field of view and will be used for large scale surveys of the northern sky, bringing back focus on the Hydrogen line for which it was designed, but large pulsar searches and other science; the Telescope has been out of operation since 2015 and is planned to be back in full operation in winter 2019. The WSRT is an International GNSS Service site. WSRT observed galaxies in the Spitzer Infrared Nearby Galaxies Survey at wavelengths of 18 and 22 cm; the WSRT site is hosting one of the two experimental EMBRACE phased array telescopes, part of the Phase 2 of the Square Kilometre Array project.
Media related to Westerbork Synthesis Radio Telescope at Wikimedia Commons
A millisecond pulsar is a pulsar with a rotational period in the range of about 1–10 milliseconds. Millisecond pulsars have been detected in the radio, X-ray, gamma ray portions of the electromagnetic spectrum; the leading theory for the origin of millisecond pulsars is that they are old rotating neutron stars which have been spun up or "recycled" through accretion of matter from a companion star in a close binary system. For this reason, millisecond pulsars are sometimes called recycled pulsars. Millisecond pulsars are thought to be related to low-mass X-ray binary systems, it is thought that the X-rays in these systems are emitted by the accretion disk of a neutron star produced by the outer layers of a companion star that has overflowed its Roche lobe. The transfer of angular momentum from this accretion event can theoretically increase the rotation rate of the pulsar to hundreds of times a second, as is observed in millisecond pulsars. However, there has been recent evidence that the standard evolutionary model fails to explain the evolution of all millisecond pulsars young millisecond pulsars with high magnetic fields, e.g. PSR B1937+21.
Bülent Kiziltan and S. E. Thorsett showed that different millisecond pulsars must form by at least two distinct processes, but the nature of the other process remains a mystery. Many millisecond pulsars are found in globular clusters; this is consistent with the spin-up theory of their formation, as the high stellar density of these clusters implies a much higher likelihood of a pulsar having a giant companion star. There are 130 millisecond pulsars known in globular clusters; the globular cluster Terzan 5 alone contains 37 of these, followed by 47 Tucanae with 22 and M28 and M15 with 8 pulsars each. Millisecond pulsars, which can be timed with high precision, are better clocks than the best atomic clocks of 1997; this makes them sensitive probes of their environments. For example, anything placed in orbit around them causes periodic Doppler shifts in their pulses' arrival times on Earth, which can be analyzed to reveal the presence of the companion and, with enough data, provide precise measurements of the orbit and the object's mass.
The technique is so sensitive that objects as small as asteroids can be detected if they happen to orbit a millisecond pulsar. The first confirmed exoplanets, discovered several years before the first detections of exoplanets around "normal" solar-like stars, were found in orbit around a millisecond pulsar, PSR B1257+12; these planets remained for many years the only Earth-mass objects known outside the Solar System. One of them, PSR B1257+12 D, has an smaller mass, comparable to that of our Moon, is still today the smallest-mass object known beyond the Solar System; the first millisecond pulsar, PSR B1937 +21, was discovered in 1982 by al.. Spinning 641 times a second, it remains the second fastest-spinning millisecond pulsar of the 200 that have been discovered. Pulsar PSR J1748-2446ad, discovered in 2005, is, as of 2012, the fastest-spinning pulsar known, spinning 716 times a second. Current theories of neutron star structure and evolution predict that pulsars would break apart if they spun at a rate of c. 1500 rotations per second or more, that at a rate of above about 1000 rotations per second they would lose energy by gravitational radiation faster than the accretion process would speed them up.
However, in early 2007 data from the Rossi X-ray Timing Explorer and INTEGRAL spacecraft discovered a neutron star XTE J1739-285 rotating at 1122 Hz. The result is not statistically significant, with a significance level of only 3 sigma. Therefore, while it is an interesting candidate for further observations, current results are inconclusive. Still, it is believed. Furthermore, one X-ray pulsar that spins at 599 revolutions per second, IGR J00291+5934, is a prime candidate for helping detect such waves in the future. "Pinning Down a Pulsar's Age". Science News. "How Millisecond Pulsars Spin So Fast". Universe Today. "Fast-Spinning Star Could Test Gravitational Waves". New Scientist. "Astronomical whirling dervishes hide their age well". Astronomy Now. Audio: Cain/Gay - Pulsars Astronomy Cast - Nov 2009
Green Bank Telescope
The Robert C. Byrd Green Bank Telescope in Green Bank, West Virginia, US is the world's largest steerable radio telescope; the Green Bank site was part of the National Radio Astronomy Observatory until September 30, 2016. Since October 1, 2016, the telescope has been operated by the newly separated Green Bank Observatory; the telescope honors the name of the late Senator Robert C. Byrd who represented West Virginia and who pushed the funding of the telescope through Congress; the Green Bank Telescope operates at meter to millimeter wavelengths. Its 100-meter diameter collecting area, unblocked aperture, good surface accuracy provide superb sensitivity across the telescope's full 0.1–116 GHz operating range. The GBT is steerable, 85% of the entire local celestial hemisphere is accessible, it is used for astronomy about 6500 hours every year, with 2000–3000 hours per year going to high-frequency science. Part of the scientific strength of the GBT is its flexibility and ease of use, allowing for rapid response to new scientific ideas.
It is scheduled dynamically to match project needs to the available weather. The GBT is readily reconfigured with new and experimental hardware; the high-sensitivity mapping capability of the GBT makes it a necessary complement to the Atacama Large Millimeter Array, the Expanded Very Large Array, the Very Long Baseline Array, other high-angular resolution interferometers. Facilities of the Green Bank Observatory are used for other scientific research, for many programs in education and public outreach, for training students and teachers; the telescope began regular science operations in 2001, making it one of the newest astronomical facilities of the US National Science Foundation. It was constructed following the collapse of a previous telescope at Green Bank, a 90.44 m paraboloid erected in 1962. The previous telescope collapsed on 15 November 1988 due to the sudden loss of a gusset plate in the box girder assembly, a key component for the structural integrity of the telescope; the telescope sits near the heart of the United States National Radio Quiet Zone, a unique area located in the town of Green Bank, West Virginia, where authorities limit all radio transmissions to avoid emissions toward the GBT and the Sugar Grove Station.
The location of the telescope within the Radio Quiet Zone allows for the detection of faint radio-frequency signals which man-made signals might otherwise mask. The observatory borders National Forest land, the Allegheny Mountains shield it from some radio interference; the telescope's location has been the site of important radio astronomy telescopes since 1957. It houses seven additional telescopes, in spite of its somewhat remote location, receives about 40,000 visitors each year, from high school students to PhD candidates to visiting researchers; the structure is 485-foot tall. The surface area of the GBT is a 100 by 110 meter active surface with 2,209 actuators for the 2,004 surface panels, making the total collecting area of 2.3 acres. The panels are made from aluminium manufactured to a surface accuracy of better than 50 micrometres RMS; the actuators adjust the panel positions to compensate for sagging, or bending under its own weight, which changes as the telescope moves. Without this so-called "active surface", observations at frequencies above 4 GHz would not be as efficient.
Unusually for a radio telescope, the primary reflector is an off-axis segment of a paraboloid. This is the same design used in familiar home satellite television dishes; the asymmetric reflector allows the telescope's focal point and feed horn to be located at the side of the dish, so that it and its retractable support boom do not obstruct the incoming radio waves, as occurs in conventional radio telescope designs with the feed located on the telescope's beam axis. The offset support arm houses a retractable prime focus feed horn in front of the 8 m subreflector and eight higher-frequency feeds on a rotating turret at the Gregorian focus. Operational frequencies range from 290 MHz to 100 GHz; because of its height and bulk, locals sometimes refer to the GBT as the “Great Big Thing”. In 2002, astronomers detected three new millisecond pulsars in the globular cluster Messier 62. In 2006, several discoveries were announced, including a large coil-shaped magnetic field in the Orion molecular cloud, a large hydrogen gas superbubble 23,000 light years away, named the Ophiuchus Superbubble.
Since 2006 numerous discoveries have been made, including the most massive neutron star detected so far, a cloud of primordial gas which surrounds other galaxies, vast molecular clouds surrounding other galaxies, complex molecules, such as sugar, in space. The National Science Foundation Astronomy Portfolio Review committee chaired by Daniel Eisenstein of Harvard University recommended in August 2012 that the Robert C. Byrd Green Bank Telescope should be defunded over a five-year period. In the fiscal year 2014 budget, the US Congress did not recommend divesting the Green Bank Telescope; the Telescope is looking for partners to help fund its $10 million annual operating costs. As of October 2016, the Green Bank Observatory has begun separation from the NSF and accepting funding from private sources to stay operational; the telescope is a key facility of the Breakthrough Listen project, in which it is used to scan for radio signals emitted by extraterrestrial technologies. In late 2017, the telescope was used to scan ʻOumuamua for signs of extra terrestrial intelligence.
Grote Reber List of radio telescopes Project Ozma Green Bank Observat
The Arecibo Observatory is a radio telescope in the municipality of Arecibo, Puerto Rico. This observatory is operated by University of Central Florida, Yang Enterprises and UMET, under cooperative agreement with the US National Science Foundation; the observatory is the sole facility of the National Astronomy and Ionosphere Center, the formal name of the observatory. From its construction in the 1960s until 2011, the observatory was managed by Cornell University. For more than 50 years, from its completion in 1963 until July 2016 when the Five hundred meter Aperture Spherical Telescope in China was completed, the Arecibo Observatory's 1,000-foot radio telescope was the world's largest single-aperture telescope, it is used in three major areas of research: radio astronomy, atmospheric science, radar astronomy. Scientists who want to use the observatory submit proposals that are evaluated by an independent scientific board; the observatory has appeared in film and television productions, gaining more recognition in 1999 when it began to collect data for the SETI@home project.
It has been listed on the US National Register of Historic Places starting in 2008. It was the featured listing in the US National Park Service's weekly list of October 3, 2008; the center was named an IEEE Milestone in 2001. It has a visitor center, open part-time. On September 21, 2017, high winds associated with Hurricane Maria caused the 430 MHz line feed to break and fall onto the primary dish, damaging about 30 out of 38,000 aluminum panels. Most Arecibo observations do not use the line feed but instead rely on the feeds and receivers located in the dome. Overall, the damage inflicted by Maria was minimal; the main collecting dish is 305 m in diameter, constructed inside the depression left by a karst sinkhole. The dish surface is made of 38,778 perforated aluminum panels, each about 3 by 6 feet, supported by a mesh of steel cables; the ground beneath supports shade-tolerant vegetation. The observatory has four radar transmitters, with effective isotropic radiated powers of 20 TW at 2380 MHz, 2.5 TW at 430 MHz, 300 MW at 47 MHz, 6 MW at 8 MHz.
The reflector is a spherical reflector, not a parabolic reflector. To aim the device, the receiver is moved to intercept signals reflected from different directions by the spherical dish surface of 270 m radius. A parabolic mirror would have varying astigmatism when the receiver is off the focal point, but the error of a spherical mirror is uniform in every direction; the receiver is on a 900-ton platform suspended 150 m above the dish by 18 cables running from three reinforced concrete towers, one 111 m high and the other two 81 m high, placing their tops at the same elevation. The platform has a rotating, bow-shaped track 93 m long, called the azimuth arm, carrying the receiving antennas and secondary and tertiary reflectors; this allows the telescope to observe any region of the sky in a forty-degree cone of visibility about the local zenith. Puerto Rico's location near the Northern Tropic allows Arecibo to view the planets in the Solar System over the Northern half of their orbit; the round trip light time to objects beyond Saturn is longer than the 2.6 hour time that the telescope can track a celestial position, preventing radar observations of more distant objects.
The origins of the observatory trace to late 1950s efforts to develop anti-ballistic missile defences as part of the newly formed ARPA's ABM umbrella-effort, Project Defender. At this early stage it was clear that the use of radar decoys would be a serious problem at the long ranges needed to attack a warhead, ranges on the order of 1,000 miles. Among the many Defender projects were several studies based on the concept that a re-entering nuclear warhead would cause unique physical signatures while still in the upper atmosphere, it was known that hot, high-speed objects caused ionization of the atmosphere that reflects radar waves, it appeared that a warhead's signature would be different enough from decoys that a detector could pick out the warhead directly, or alternately, provide added information that would allow operators to focus a conventional tracking radar on the single return from the warhead. Although the concept appeared to offer a solution to the tracking problem, there was no information on either the physics of re-entry or a strong understanding of the normal composition of the upper layers of the ionosphere.
ARPA began to address both simultaneously. To better understand the radar returns from a warhead, several radars were built on Kwajalein Atoll, while Arecibo started with the dual purpose of understanding the ionosphere's F-layer while producing a general-purpose scientific radio observatory; the observatory was built between mid-1960 and November 1963. William E. Gordon of Cornell University oversaw its design, who intended to use it to study the Earth's ionosphere, he was attracted to the sinkholes in the karst regions of Puerto Rico that offered perfect cavities for a large dish. A fixed parabolic reflector was envisioned, pointing in a fixed direction with a 150 m tower to hold equipment at the focus; this design would have limited its use in other research areas, such as radar astronomy, radio astronomy and atmospheric science, which require the ability to point at different positions in the sky and track those positions for an extended time as Earth rotates. Ward Low of the Advanced Research Projects Agency pointed out this flaw and put Gordon in touch with the Air Force Cambridge Research Laboratory in Boston, where one group headed by Phil Blacksmith was working
The Fermilab Holometer in Illinois is intended to be the world's most sensitive laser interferometer, surpassing the sensitivity of the GEO600 and LIGO systems, theoretically able to detect holographic fluctuations in spacetime. According to the director of the project, the Holometer should be capable of detecting fluctuations in the light of a single attometer, meeting or exceeding the sensitivity required to detect the smallest units in the universe called Planck units. Fermilab states: "Everyone is familiar these days with the blurry and pixelated images, or noisy sound transmission, associated with poor internet bandwidth; the Holometer seeks to detect the equivalent blurriness or noise in reality itself, associated with the ultimate frequency limit imposed by nature."Craig Hogan, a particle astrophysicist at Fermilab, states about the experiment, "What we’re looking for is when the lasers lose step with each other. We’re trying to detect the smallest unit in the universe; this is great fun, a sort of old-fashioned physics experiment where you don’t know what the result will be."
Experimental physicist Hartmut Grote of the Max Planck Institute in Germany states that although he is skeptical that the apparatus will detect the holographic fluctuations, if the experiment is successful "it would be a strong impact to one of the most open questions in fundamental physics. It would be the first proof that space-time, the fabric of the universe, is quantized."Holometer has started, in 2014, collecting data that will help determine whether the universe fits the holographic principle. The hypothesis that holographic noise may be observed in this manner has been criticized on the grounds that the theoretical framework used to derive the noise violates Lorentz-invariance. Lorentz-invariance violation is however strongly constrained an issue, unsatisfactorily addressed in the mathematical treatment; the Fermilab holometer has found other uses than studying the holographic fluctuations of spacetime. It has shown constraints on the existence of high-frequency gravitational waves and primordial black holes.
The Holometer will consist of two 39m arm-length power-recycled Michelson interferometers, similar to the LIGO instruments. The interferometers will be able to be operated in two spatial configurations, termed "nested" and "back-to-back". According to Hogan's hypothesis, in the nested configuration the interferometers' beamsplitters should appear to wander in step with each other; the presence or absence of the correlated wandering effect in each configuration can be determined by cross-correlating the interferometers' outputs. The experiment started one year of data collection in August 2014. A paper about the project titled Now Broadcasting in Planck Definition by Craig Hogan ends with the statement "We don't know what we will find."A new result of the experiment released on December 3, 2015, after a year of data collection, has ruled out Hogan's theory of a pixelated universe to a high degree of statistical significance. The study found. Fermilab Holometer
The Virgo interferometer is a large interferometer designed to detect gravitational waves predicted by the general theory of relativity. Virgo is a Michelson interferometer, isolated from external disturbances: its mirrors and instrumentation are suspended and its laser beam operates in a vacuum; the instrument's two arms are three kilometres long and located in Santo Stefano a Macerata, near the city of Pisa, Italy. Virgo is part of a scientific collaboration of laboratories from six countries: Italy and France, the Netherlands, Poland and Spain. Other interferometers similar to Virgo have the same goal of detecting gravitational waves, including the two LIGO interferometers in the United States. Since 2007, Virgo and LIGO have agreed to share and jointly analyze the data recorded by their detectors and to jointly publish their results; because the interferometric detectors are not directional and they are looking for signals which are weak, one-time events, simultaneous detection of a gravitational wave in multiple instruments is necessary to confirm the signal validity and to deduce the angular direction of its source.
The interferometer is named for the Virgo Cluster of about 1,500 galaxies in the Virgo constellation, about 50 million light-years from Earth. As no terrestrial source of gravitational wave is powerful enough to produce a detectable signal, Virgo must observe the Universe; the more sensitive the detector, the further it can see gravitational waves, which increases the number of potential sources. This is relevant as the violent phenomena Virgo is sensitive to are rare: the more galaxies Virgo is surveying, the larger the probability of a detection; the Virgo project was approved in 1993 by the French CNRS and in 1994 by the Italian INFN, the two institutes at the origin of the experiment. The construction of the detector started in 1996 in the Cascina site near Italy. In December 2000, CNRS and INFN created the European Gravitational Observatory joined by the Netherlands, Poland and Spain. EGO is responsible for the Virgo site, in charge of the construction, the maintenance and the operation of the detector, as well as of its upgrades.
The goal of EGO is to promote research and studies about gravitation in Europe. By December 2015, 19 laboratories plus EGO were members of the Virgo collaboration. In the 2000s, the "initial" Virgo detector was built and operated; the instrument reached its design sensitivity to gravitational wave signals. This long-term endeavour allowed. However, the initial Virgo detector was not sensitive enough to achieve such a detection. Therefore, it was decommissioned from 2011 in order to be replaced by the "advanced" Virgo detector which aims at increasing its sensitivity by a factor of 10; the advanced Virgo detector benefits from the experience gained on the initial detector and from technological advances since it was made. The construction of the initial Virgo detector was completed in June 2003 and several data taking periods followed between 2007 and 2011; some of these runs were done in coincidence with the two LIGO detectors. A long upgrade to the second generation detector, called Advanced Virgo, started.
Advanced Virgo started commissioning in 2016, joining the two advanced LIGO detectors for a first "engineering" observing period in May and June 2017. On 14 August 2017, LIGO and Virgo detected a signal, GW170814, reported on 27 September 2017, it was the first binary black hole merger detected by both Virgo. The first goal of Virgo is to directly observe gravitational waves, a straightforward prediction of Albert Einstein's general relativity; the study over three decades of the binary pulsar 1913+16, whose discovery was awarded the 1993 Nobel Prize in Physics, led to indirect evidence of the existence of gravitational waves. The observed evolution over time of this binary pulsar's orbital period is in excellent agreement with the hypothesis that the system is losing energy by emitting gravitational waves; the rotation motion is accelerating and the two compact stars get closer by about three meters each year. They should coalesce in about 300 million years, but only the last moments preceding that particular cosmic collision will generate gravitational waves strong enough to be visible in a detector like Virgo.
This theoretical scenario for the evolution of Binary Pulsar B1913+16 would be confirmed by a direct detection of gravitational waves from a similar system, the main goal of giant interferometric detectors like Virgo and LIGO. On the longer term, after accomplishing the primary goal of discovering gravitational waves, Virgo aims at being part of the birth of a new branch of astronomy by observing the Universe with a different and complementary perspective than current telescopes and detectors. Information brought by gravitational waves will be added to those provided by the study of the electromagnetic spectrum, of cosmic rays and of neutrinos. In order to correlate a gravitational wave detection with visible and localized events in the sky