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35-489: Because the Sun is uniquely situated for close-range observing (other stars cannot be resolved with anything like the spatial or temporal resolution that the Sun can), there is a split between the related discipline of observational astrophysics (of distant stars) and observational solar physics. The study of solar physics is also important as it provides a "physical laboratory" for the study of plasma physics. Babylonians were keeping

70-469: A Solar Vacuum Tower Telescope was started by the architect and engineer Charles W. Jones in 1963. Construction on the final building started in 1966 under the U.S. Army Corps of Engineers and ended in 1967, at a cost of about $ 3 million, with the architectural firm of Roghlin and Baran, Associates. Richard B. Dunn, for whom the instrument was eventually dedicated, wrote an article in Sky & Telescope about

105-497: A better understanding of the Sun. Scientists and engineers use the telescope to investigate a range of solar activities, often in concert with satellites or rocket launches, and to develop new technologies for the 4-meter Daniel K. Inouye Solar Telescope . The telescope was inaugurated as the world's premier high spatial resolution optical solar telescope in 1969. With a horizontal rotating 40-foot-diameter (12 m) observing platform, such that instruments do not have to be mounted on

140-399: A day, at specific position of the Sun in the sky. As such, accurate observations of the Sun and its trajectory on the sky were needed. In the late 10th century, Iranian astronomer Abu-Mahmud Khojandi built a massive observatory near Tehran. There, he took accurate measurements of a series of meridian transits of the Sun, which he later used to calculate the obliquity of the ecliptic. Following

175-406: A flexibility to allow for the combination of any many spectral lines, "limited only by practical considerations (e.g., the number of detectors available, space on the optical bench, etc.)". The Interferometric Bidimensional Spectro-polarimeter (IBIS) is a dual interferometer, imaging spectropolarimeter. It uses a series of precise piezoelectric tuning to rapidly scan selected spectral lines within

210-501: A record of solar eclipses, with the oldest record originating from the ancient city of Ugarit, in modern-day Syria. This record dates to about 1300 BC. Ancient Chinese astronomers were also observing solar phenomena (such as solar eclipses and visible sunspots) with the purpose of keeping track of calendars, which were based on lunar and solar cycles. Unfortunately, records kept before 720 BC are very vague and offer no useful information. However, after 720 BC, 37 solar eclipses were noted over

245-649: Is a multi-slit spectropolarimeter made specifically for the Dunn Solar Telescope to study magnetism on the solar surface. The instrument samples adjacent slices of the solar surface using four parallel slits to achieve high cadence, diffraction-limited , precision spectropolarimetry. Up to four spectral lines at visible and infrared wavelengths, covering four different heights in the solar atmosphere, can be observed simultaneously. It can be optimized to provide simultaneous spectral coverage at visible (3,500 – 10,000 Å) and infrared (9,000 – 24,000 Å) wavelengths through

280-494: Is a two channel imaging spectrograph that first flew in 2006. It observes the solar corona with high spectral resolution. So far, it has provided information on the nature of coronal bright points, cool transients and coronal loop arcades. Data from it also helped calibrating SOHO and a few other telescopes. Al-Khujandi Abu Mahmud Hamid ibn al-Khidr al-Khujandi (known as Abu Mahmood Khujandi , al-khujandi or Khujandi , Persian: ابومحمود خجندی, c.  940 - 1000)

315-550: Is hung on three bolts, each only 76 millimeters (3.0 in) in diameter. Despite the size and weight, much of the telescope can be controlled and monitored from a single control room, off to one side of the main instrument observing table. The Dunn Solar Telescope has a rotating optical bench, which can be configured to multiple observing setups, depending on the requirements of the science under study. The four most widely used instruments, often used together in one complex observing setup, are: The Facility Infrared Spectropolarimeter

350-519: The American Astronomical Society boasts 555 members (as of May 2007), compared to several thousand in the parent organization. A major thrust of current (2009) effort in the field of solar physics is integrated understanding of the entire Solar System including the Sun and its effects throughout interplanetary space within the heliosphere and on planets and planetary atmospheres . Studies of phenomena that affect multiple systems in

385-722: The Richard B. Dunn Solar Telescope , is a unique vertical-axis solar telescope that specializes in high-resolution imaging and spectroscopy . It is located at Sacramento Peak in Sunspot, New Mexico . It is the main telescope at the Sunspot Solar Observatory , operated by New Mexico State University in partnership with the National Solar Observatory through funding from the National Science Foundation ,

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420-550: The 550 and 860 nm range. This creates a time series of high-fidelity imaging, spectroscopy, and polarimetry of the Sun. It has a large circular field-of-view combined with high spectral (R ≥ 200,000), spatial ≃ 0.2″) and temporal resolution (several frames per second). The Rapid Oscillations in the Solar Atmosphere (ROSA) instrument is a single-controlled system of six imaging fast-readout CCD cameras. The full chip on each camera can be read out 30 frames per second, and all

455-518: The Earth's axial tilt ("obliquity of the ecliptic") to high precision. He determined the axial tilt to be 23°32'19" for the year 994 AD. He noted that measurements by earlier astronomers had found higher values (Indians: 24°; Ptolemy 23° 51') and thus discovered that the axial tilt is not constant but is in fact (currently) decreasing. His measurement of the axial tilt was however about 2 minutes too small, probably due to his heavy instrument settling over

490-705: The New Solar Telescope(NTS) which is a 1.6 meter, clear-aperture, off-axis Gregorian telescope. The NTS saw first light in December 2008. Until the ATST comes on line, the NTS remains the largest solar telescope in the world. The Big Bear Observatory is one of several facilities operated by the Center for Solar-Terrestrial Research at New Jersey Institute of Technology (NJIT). The Extreme Ultraviolet Normal Incidence Spectrograph (EUNIS)

525-687: The Sun of any artificial object. The Advanced Technology Solar Telescope (ATST) is a solar telescope facility that is under construction in Maui. Twenty-two institutions are collaborating on the ATST project, with the main funding agency being the National Science Foundation. Sunspot Solar Observatory (SSO) operates the Richard B. Dunn Solar Telescope (DST) on behalf of the NSF. The Big Bear Solar Observatory in California houses several telescopes including

560-596: The Sun. A publicly funded mission led by the Japanese Aerospace Exploration Agency, the HINODE satellite, launched in 2006, consists of a coordinated set of optical, extreme ultraviolet and X-ray instruments. These investigate the interaction between the solar corona and the Sun's magnetic field. The Solar Dynamics Observatory (SDO) was launched by NASA in February 2010 from Cape Canaveral. The main goals of

595-481: The autumn of 1611, Johannes Fabricius wrote the first book on sunspots, De Maculis in Sole Observatis ("On the spots observed in the Sun"). Modern day solar physics is focused towards understanding the many phenomena observed with the help of modern telescopes and satellites. Of particular interest are the structure of the solar photosphere, the coronal heat problem and sunspots. The Solar Physics Division of

630-428: The cameras are triggered from one control system. As such, it provides the ability to image multiple layers of the photosphere and chromosphere simultaneously. At its installation in 2010, it generated up to 12 TB of data per day, making it one of the largest datasets in ground-based solar astronomy at the time. In addition, some older instruments are available, although these are now rarely used: A design for

665-423: The completion of the instrument in 1969. As quoted from the article: "In our design we wanted most of all to eliminate problems of local seeing, which are discussed at every meeting on solar instrumentation. Solar astronomers worry about turbulence caused by the slot in the observatory dome, heating of the dome surfaces, heating of the telescope, local convection, and turbulence within the optical system...In our case,

700-511: The course of 240 years. Astronomical knowledge flourished in the Islamic world during medieval times. Many observatories were built in cities from Damascus to Baghdad, where detailed astronomical observations were taken. Particularly, a few solar parameters were measured and detailed observations of the Sun were taken. Solar observations were taken with the purpose of navigation, but mostly for timekeeping. Islam requires its followers to pray five times

735-458: The course of the observations. Khujandi stated a special case of Fermat's Last Theorem for n = 3, but his attempted proof of the theorem was incorrect. The spherical law of sines may have also been discovered by Khujandi, but it is uncertain whether he discovered it first, or whether Abu Nasr Mansur , Abul Wafa or Nasir al-Din al-Tusi discovered it first. Richard B. Dunn Solar Telescope The Dunn Solar Telescope , also known as

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770-463: The dome was eliminated. We put a window high up on a 135-foot pyramidal tower and then evacuated the air from the entire telescope inside the tower. The latter reduces the effects of local convection and the vacuum eliminates the internal turbulence and seeing problems. Also, it provides the comfort of a heated observing room [...]" The tower telescope was originally dedicated on October 15, 1969, and renamed in 1998 after Richard B. Dunn . A plaque at

805-515: The facility reads: "Named in honor of one of solar astronomy's most creative instrument builders, this vacuum tower telescope is the masterpiece of Richard B. Dunn's long scientific career at Sacramento Peak Observatory (1998). Construction of the vacuum tower used for the DST significantly impacted future solar instruments: So sharp were the images formed from this type of solar telescope, that almost every large solar telescope built since then has been based on

840-711: The fall of the Western Roman Empire, Western Europe was cut from all sources of ancient scientific knowledge, especially those written in Greek. This, plus de-urbanisation and diseases such as the Black Death led to a decline in scientific knowledge in Medieval Europe, especially in the early Middle Ages. During this period, observations of the Sun were taken either in relation to the zodiac, or to assist in building places of worship such as churches and cathedrals. In astronomy,

875-518: The heliosphere, or that are considered to fit within a heliospheric context, are called heliophysics , a new coinage that entered usage in the early years of the current millennium. Helios-A and Helios-B are a pair of spacecraft launched in December 1974 and January 1976 from Cape Canaveral, as a joint venture between the German Aerospace Center and NASA. Their orbits approach the Sun closer than Mercury. They included instruments to measure

910-433: The light and reflects it back up, where it exits the vacuum tube through six quartz optical windows in the floor of an optical laboratory at ground level. The telescope's entire optical system – from the top of the tower to the base of its underground portion, plus the 40-foot-diameter (12 m) observing room floor – is contained within the vacuum tube. The optics are evacuated to eliminate distortion due to convection in

945-431: The lowest excavated point (the bottom of the sump) is 228 feet (69 m) below ground. Enclosed within the concrete tower is a vertical vacuum tube with 3-foot-thick walls. The optical path starts at a heliostat on top of the tower. An entrance window at the top of the tower, and two mirrors, reflect sunlight down the vacuum tube to the 64-inch primary mirror, 193 feet (59 m) underground. The primary mirror focuses

980-400: The mission are understanding how solar activity arises and how it affects life on Earth by determining how the Sun's magnetic field is generated and structured and how the stored magnetic energy is converted and released into space. The Parker Solar Probe (PSP) was launched in 2018 with the mission of making detailed observations of the outer solar corona. It has made the closest approaches to

1015-411: The renaissance period started with the work of Nicolaus Copernicus . He proposed that planets revolve around the Sun and not around the Earth, as it was believed at the time. This model is known as the heliocentric model. His work was later expanded by Johannes Kepler and Galileo Galilei . Particularly, Galilei used his new telescope to look at the Sun. In 1610, he discovered sunspots on its surface. In

1050-401: The solar wind, magnetic fields, cosmic rays, and interplanetary dust. Helios-A continued to transmit data until 1986. The Solar and Heliospheric Observatory, SOHO, is a joint project between NASA and ESA that was launched in December 1995. It was launched to probe the interior of the Sun, make observations of the solar wind and phenomena associated with it and investigate the outer layers of

1085-612: The state of New Mexico, and private funds from other partners. The Dunn Solar Telescope helps astrophysicists worldwide better understand the Sun and how it affects Earth. Completed in 1969, the telescope was upgraded with high-order adaptive optics in 2004 and remains a highly versatile astrophysical observatory that serves as an important test platform for developing new instrumentation and technologies. The Dunn Solar Telescope specializes in solar high-resolution imaging and spectroscopy. These observations allow solar astronomers worldwide to obtain

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1120-453: The telescope itself, the Dunn Solar Telescope continues to offer a versatile, user-friendly setup. It has two high-order adaptive optics benches to compensate for blurring by Earth's atmosphere. The whole building from top to bottom is a single instrument. Like an iceberg, only a part of the telescope's bulk is visible above ground. More than half the entire building is underground – the tower extends 136 feet (41 m) feet above ground, while

1155-419: The telescope that would otherwise be caused by the great heat produced by focusing sunlight. The interior vacuum tube, which weighs more than 250 tons, is suspended from the top of the tower by a mercury float bearing that contains 10 tons of mercury. This bearing allows the entire vacuum tube to be rotated, compensating for the apparent rotation of the image as the Sun rises into the sky. The bearing, in turn,

1190-446: The use of a unique dual-armed design. It was "designed to capture the Fe I 6302 Å and Fe I 15648 Å or He I 10830 Å lines with maximum efficiency." The Spectro-Polarimeter for Infrared and Optical Regions performs achromatic lens Stokes polarimetry across several visible and infrared spectral regions. Completed in 2005, it was designed to act as 'experimental oriented' instrument, built with

1225-586: Was a Muslim Transoxanian astronomer and mathematician born in Khujand (now part of Tajikistan ) who lived in the late 10th century and helped build an observatory , near the city of Ray (near today's Tehran ), in Iran . Khujandi worked under the patronage of the Buwayhid Amirs at the observatory near Ray, Iran , where he is known to have constructed the first huge mural sextant in 994 AD, intended to determine

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