However, using an astronomical interferometer, measurements of the radius of the star can be made directly to an accuracy of 0. 5 %.

Surprisingly the first use of a radio interferometer for an astronomical observation was carried out by Payne-Scott, Pawsey and Lindsay McCready on 26 January 1946 using a SINGLE converted radar antenna ( broadside array ) at 200 MHz near Sydney, Australia.

They used an astronomical interferometer at the Mount Wilson Observatory to measure the diameter of the super-giant star Betelgeuse.

A century later, the specific interferometer instrumentation design produced by Albert Michelson has become the principle means to conduct astronomical interferometry.

The VLT consists of an arrangement of four large ( 8. 2 meter diameter ) telescopes ( called Unit Telescopes or UTs ) with optical elements that can combine them into an astronomical interferometer ( VLTI ), which is used to resolve small objects.

The telescopes can operate together to form a single astronomical interferometer.

# Atmospheric seeing causes the fringes in an astronomical interferometer to move rapidly

* December 13-The red giant star Betelgeuse is the first to have its diameter determined by an optical astronomical interferometer, the Michelson stellar interferometer on Mount Wilson Observatory's reflector telescope.

* Infrared Spatial Interferometer, an astronomical interferometer array of three telescopes

See astronomical interferometer for more information.

COAST, the Cambridge Optical Aperture Synthesis Telescope, is a multi-element optical astronomical interferometer with baselines of up to 100 metres, which uses aperture synthesis to observe stars with angular resolution as high as one thousandth of one arcsecond ( producing images with much higher resolution than can be obtained using individual telescopes such as the Hubble Space Telescope ).

The most recent design envisaged three free-flying space telescopes, each three to four metres in diameter, flying in formation as an astronomical interferometer.

Antoine Labeyrie has proposed a much larger space-based astronomical interferometer similar to Darwin, but with the individual telescopes positioned in a spherical arrangement and with an emphasis on interferometric imaging.

Capella also became the first astronomical object to be imaged by a separate element optical interferometer when it was imaged by the Cambridge Optical Aperture Synthesis Telescope in September 1995.

* the length of an astronomical interferometer

Payne-Scott played a major role in the first-ever radio astronomical interferometer observation from 26 January 1946, when the sea-cliff interferometer was used to determine the position and angular size of a solar burst.

The Navy Precision Optical Interferometer ( NPOI ) is a major astronomical interferometer ( world's largest baselines ), operated by the Naval Observatory Flagstaff Station ( NOFS ) in collaboration with the Naval Research Laboratory ( NRL ) and Lowell Observatory.

The NPOI is an astronomical interferometer laid out in a three-arm " Y " configuration, with each equally-spaced arm measuring long.

This array of holes acts as a miniature astronomical interferometer.

These telescopes form an astronomical interferometer where all the signals are combined in a purpose-built computer ( a correlator ) to produce high-resolution astronomical images.

The Institut de radioastronomie millimétrique ( IRAM ) operates two observatories for radio astronomy at millimeter wavelengths, which are open to the international astronomical community: the 30-m single-dish radio telescope located on Pico Veleta ( 2850 m ) in the Spanish Sierra Nevada ( Andalucia, Spain ), and the six-antenna interferometer on the Plateau de Bure ( 2550 m ) in the French Alps.

Astrology consists of a number of belief systems which hold that there is a relationship between astronomical phenomena and events in the human world.

The Diosemeia consists of forecasts of the weather from astronomical phenomena, with an account of its effects upon animals.

The TAC consists of about 100 members of the U. S. and international astronomical community, selected to represent a broad range of research expertise needed to evaluate the proposals.

The current astronomical model for the nebula consists of an ionized region roughly centered on Theta < sup > 1 </ sup > Orionis C, the star responsible for most of the ultraviolet ionizing radiation.

A large part of the volume consists of mathematical and astronomical tables, since Harris intended his work to serve as a small mathematical library.

A galaxy is a massive, gravitationally bound astronomical system that consists of a large number of stars and other matter.

The second pair, around 10, 000 astronomical units from the first, consists of two faint, small and relatively cool red dwarfs.

The binary system consists of two red dwarf stars orbiting each other at a distance of 1. 9 astronomical units.

It consists of two red dwarf stars in a nearly circular orbit with a separation of about 147 astronomical units.

The Xi Scorpii system consists of at least five stars in two groups separated by 4. 67 arcminutes ( or 0. 08 °) on the sky, corresponding to a distance of at least 8000 astronomical units ( AU ).

After an unspeakable siege, lasting the better part of two months, it was announced that the studio `` owed '' the government a tax debt in excess of eight million dollars while I, who had always remained aloof from such iniquitous practices as paying taxes on the salary I had earned and the little I legally inherited as Morris' helpless relict, was `` stung '' with a personal bill of such astronomical proportions as to `` wipe out '' all but a fraction of my poor, hard-come-by savings.

Woodcut showing the 16th century astronomical clock of Uppsala Cathedral, with two clockfaces, one with Arabic and one with Roman numerals.

After the separation of the two offices the position of Astronomer Royal has been largely honorary, though he remains available to advise the Sovereign on astronomical and related scientific matters, and the office is of great prestige.

The discovery that the comet was likely to collide with Jupiter caused great excitement within the astronomical community and beyond, as astronomers had never before seen two significant Solar System bodies collide.

The 14th of the paschal lunar month is designated by convention as the Paschal full moon, although the 14th of the lunar month may differ from the date of the astronomical full moon by up to two days.

With 24 optical and two radio telescopes, it is the largest, most diverse gathering of astronomical instruments in the world.

Johannes Kepler published his first two laws in 1609, having found them by analyzing the astronomical observations of Tycho Brahe.

A civil twilight period of about two weeks occurs before sunrise and after sunset, a nautical twilight period of about five weeks occurs before sunrise and after sunset and an astronomical twilight period of about seven weeks occurs before sunrise and after sunset.

Most of the ancients, including the first two just mentioned, refer to his work by his name: " Pytheas says ..." Two late writers give titles: the astronomical author Geminus of Rhodes mentions ( ta peri tou Okeanou ), literally " things about the Ocean ", sometimes translated as " Description of the Ocean ", " On the Ocean " or " Ocean ;" Marcianus, the scholiast on Apollonius of Rhodes, mentions a ( periodos gēs ), a " trip around the earth " or ( periplous ), " sail around.

( Note: Astronomy should not be confused with astrology, which assumes that people's destiny and human affairs in general are correlated to the apparent positions of astronomical objects in the sky -- although the two fields share a common origin, they are quite different ; astronomers embrace the scientific method, while astrologers do not.

Right ascension ( abbreviated RA ; symbol α ) is the astronomical term for one of the two direction coordinates of a point on the celestial sphere in the equatorial coordinate system, usually combined with declination.

The Aristotelian model was accepted in the Western world for roughly two millennia, until Copernicus revived Aristarchus ' theory that the astronomical data could be explained more plausibly if the earth rotated on its axis and if the sun were placed at the center of the universe.

Ptolemy ( 2nd century CE ) also mentions, in his work Almagest ( VII. 3 ), two astronomical observations made by Menelaus in Rome in January of the year 98.

A conjunction occurs when two astronomical objects have either the same right ascension or the same ecliptical longitude, normally when observed from the Earth.

In contrast, the term appulse is defined as the minimum apparent separation on the sky of two astronomical bodies.

A conjunction, as a phenomenon of perspective, is an event that involves two astronomical bodies seen by an observer on the Earth.

The clock tower featured large astronomical instruments of the armillary sphere and celestial globe, both driven by an early intermittently working escapement mechanism ( roughly two centuries before the discrete verge escapement of true mechanical clocks appeared in medieval clockworks ).

He carried his enquiries so far into the occult sciences of abstruse and hidden nature, that, after having given most ample proofs, by his writings concerning physiognomy, geomancy, and chiromancy, he moved on to the study of philosophy, physics, and astrology ; which studies proved so advantageous to him, that, not to speak of the two first, which introduced him to all the popes of his time, and acquired him a reputation among learned men, it is certain that he was a great master in the latter, which appears not only by the astronomical figures he had painted in the great hall of the palace at Padua, and the translations he made of the books of the most learned rabbi Abraham Aben Ezra, added to those he himself composed on critical days, and the improvement of astronomy, but by the testimony of the renowned mathematician Regiomontanus, who made a fine panegyric on him, in quality of an astrologer, in the oration he delivered publicly at Padua when he explained there the book of Alfraganus.

* First contact, the moment in astronomical transit when the apparent positions of the two bodies first touch

Much larger binoculars have been made by amateur telescope makers, essentially using two refracting or reflecting astronomical telescopes.

Several poetical works on various subjects, as well as a number of prose epistles, are attributed to Aratus, but none of them have come down to us, except his two astronomical poems in hexameter.

These two components are more than 500 astronomical units apart, with an estimated orbital period of approximately 3600 years.

Diurnal motion is an astronomical term referring to the apparent daily motion of stars around the Earth, or more precisely around the two celestial poles.

Amongst them may be mentioned a history of the dispute with Palamas ; biographies of his uncle and early instructor John, metropolitan of Heraclea, and of the martyr Codratus of Antioch ; funeral orations for Theodore Metochites, and the two emperors Andronicus ; commentaries on the wanderings of Odysseus and on Synesius's treatise on dreams ; tracts ‘ on orthography and on words of doubtful meaning ; a philosophical dialogue called Phlorentius or Concerning Wisdom ; astronomical treatises on the date of Easter, on the preparation of the astrolabe and on the predictive calculation of solar eclipses ; and an extensive correspondence.

The number of his astronomical publications exceeds 150, but his reputation depends mainly on his earlier work at Greenwich and his two great star catalogues — the Cape catalogue for 1880 and the Radcliffe catalogue for 1890.