Astrometry is a branch of astronomy that involves precise measurements of the positions and movements of stars and other celestial bodies. It provides the kinematics and physical origin of the Solar System and this galaxy, the Milky Way.
Arcturus is the brightest star in the northern constellation of Boötes. With an apparent visual magnitude of −0.05, it is the fourth-brightest star in the night sky, and the brightest in the northern celestial hemisphere. The name Arcturus originated from ancient Greece; it was then cataloged as α Boötis by Johann Bayer in 1603, which is Latinized to Alpha Boötis. Arcturus forms one corner of the Spring Triangle asterism.
Hipparchus was a Greek astronomer, geographer, and mathematician. He is considered the founder of trigonometry, but is most famous for his incidental discovery of the precession of the equinoxes. Hipparchus was born in Nicaea, Bithynia, and probably died on the island of Rhodes, Greece. He is known to have been a working astronomer between 162 and 127 BC.
In textual studies, a palimpsest is a manuscript page, either from a scroll or a book, from which the text has been scraped or washed off in preparation for reuse in the form of another document. Parchment was made of lamb, calf, or kid skin and was expensive and not readily available, so, in the interest of economy, a page was often re-used by scraping off the previous writing. In colloquial usage, the term palimpsest is also used in architecture, archaeology and geomorphology to denote an object made or worked upon for one purpose and later reused for another; for example, a monumental brass the reverse blank side of which has been re-engraved.
A star catalogue is an astronomical catalogue that lists stars. In astronomy, many stars are referred to simply by catalogue numbers. There are a great many different star catalogues which have been produced for different purposes over the years, and this article covers only some of the more frequently quoted ones. Star catalogues were compiled by many different ancient people, including the Babylonians, Greeks, Chinese, Persians, and Arabs. They were sometimes accompanied by a star chart for illustration. Most modern catalogues are available in electronic format and can be freely downloaded from space agencies' data centres. The largest is being compiled from the spacecraft Gaia and thus far has over a billion stars.
Proper motion is the astrometric measure of the observed changes in the apparent places of stars or other celestial objects in the sky, as seen from the center of mass of the Solar System, compared to the abstract background of the more distant stars.
Hipparcos was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993. It was the first space experiment devoted to precision astrometry, the accurate measurement of the positions of celestial objects on the sky. This permitted the first high-precision measurements of the intrinsic brightnesses proper motions, and parallaxes of stars, enabling better calculations of their distance and tangential velocity. When combined with radial velocity measurements from spectroscopy, astrophysicists were able to finally measure all six quantities needed to determine the motion of stars. The resulting Hipparcos Catalogue, a high-precision catalogue of more than 118,200 stars, was published in 1997. The lower-precision Tycho Catalogue of more than a million stars was published at the same time, while the enhanced Tycho-2 Catalogue of 2.5 million stars was published in 2000. Hipparcos' follow-up mission, Gaia, was launched in 2013.
The Guide Star Catalog (GSC), also known as the Hubble Space Telescope, Guide Catalog (HSTGC), is a star catalog compiled to support the Hubble Space Telescope with targeting off-axis stars. GSC-I contained approximately 20,000,000 stars with apparent magnitudes of 6 to 15. GSC-II contains 945,592,683 stars out to magnitude 21. As far as possible, binary stars and non-stellar objects have been excluded or flagged as not meeting the requirements of Fine Guidance Sensors. This is the first full sky star catalog created specifically for navigation in outer space.
Gamma Eridani, formally named Zaurak, is a variable star in the constellation of Eridanus. It is visible to the naked eye with an apparent visual magnitude that varies around 2.9, and lies at a distance of about 203 light years from the Sun, as determined by the Hipparcos astrometry satellite.
The Catasterismi or Catasterisms is a lost work by Eratosthenes of Cyrene. It was a comprehensive compendium of astral mythology including origin myths of the stars and constellations. Only a summary of the original work survives, called the Epitome Catasterismorum, by an unknown author sometimes referred to as pseudo-Eratosthenes.
Ancient Greek astronomy is the astronomy written in the Greek language during classical antiquity. Greek astronomy is understood to include the Ancient Greek, Hellenistic, Greco-Roman, and late antique eras. Ancient Greek astronomy can be divided into three primary phases: Classical Greek Astronomy, which encompassed the 5th and 4th centuries BC, and Hellenistic Astronomy, which encompasses the subsequent period until the formation of the Roman Empire ca. 30 BC, and finally Greco-Roman astronomy, which refers to the continuation of the tradition of Greek astronomy in the Roman world. During the Hellenistic era and onwards, Greek astronomy expanded beyond the geographic region of Greece as the Greek language had become the language of scholarship throughout the Hellenistic world, in large part delimited by the boundaries of the Macedonian Empire established by Alexander the Great. The most prominent and influential practitioner of Greek astronomy was Ptolemy, whose treatise Almagest shaped astronomical thinking until the modern era. Most of the most prominent constellations known today are taken from Greek astronomy, albeit via the terminology they took on in Latin.
In astronomy, Durchmusterung or Bonner Durchmusterung (BD) is an astrometric star catalogue of the whole sky, published by the Bonn Observatory in Germany from 1859 to 1863, with an extension published in Bonn in 1886. The name comes from Durchmusterung, a German word used for a systematic survey of objects or data. The term has sometimes been used for other astronomical surveys, including not only stars, but also the search for other celestial objects. Special tasks include celestial scanning in electromagnetic wavelengths shorter or longer than visible light waves.
Tyndale House is an independent biblical studies library in Cambridge, England, with a Christian foundation. Founded in 1945, it aims to provide specialist resources in support of research into the Old and New Testaments, along with relevant historical backgrounds.
Delta Ceti, Latinized from δ Ceti, is a single, blue-white hued star in the equatorial constellation of Cetus. The star's apparent visual magnitude of +4.06 means it is near to the cusp of the faintest third of the stars that are visible the ideally-placed naked eye. It is 0.3238° north of the celestial equator compared to the celestial north pole's 90°. The star is positioned about 0.74° WNW of the spiral galaxy M77, but which at apparent magnitude 9.6 needs magnification to be made out and has an apparent size of only 0.1° by 0.12°.
Christian Palestinian Aramaic was a Western Aramaic dialect used by the Melkite Christian community, probably of Jewish descent, in Palestine, Transjordan and Sinai between the fifth and thirteenth centuries. It is preserved in inscriptions, manuscripts and amulets. All the medieval Western Aramaic dialects are defined by religious community. CPA is closely related to its counterparts, Jewish Palestinian Aramaic (JPA) and Samaritan Aramaic (SA). CPA shows a specific vocabulary that is often not paralleled in the adjacent Western Aramaic dialects.
Agnes Smith Lewis (1843–1926) and Margaret Dunlop Gibson (1843–1920), nées Smith, were English Semitic scholars and travellers. As the twin daughters of John Smith of Irvine, Ayrshire, Scotland, they learned more than 12 languages between them, specialising in Arabic, Christian Palestinian Aramaic, and Syriac, and became acclaimed scholars in their academic fields, and benefactors to the Presbyterian Church of England, especially to Westminster College, Cambridge.
Codex Climaci Rescriptus is a collective palimpsest manuscript consisting of several individual manuscripts underneath, Christian Palestinian Aramaic texts of the Old and New Testament as well as two apocryphal texts, including the Dormition of the Mother of God, and is known as Uncial 0250 with a Greek uncial text of the New Testament and overwritten by Syriac treatises of Johannes Climacus : the scala paradisi and the liber ad pastorem. Paleographically the Greek text has been assigned to the 7th or 8th century, and the Aramaic text to the 6th century. It originates from Saint Catherine's Monastery going by the New Finds of 1975. Formerly it was classified for CCR 5 and CCR 6 as lectionary manuscript, with Gregory giving the number ℓ 1561 to it.
42 Persei is a binary star system in the northern constellation of Perseus. It has the Bayer designation n Persei, while 42 Persei is the Flamsteed designation. The system is visible to the naked eye as a dim, white-hued point of light with an apparent visual magnitude of 5.11. It is located around 93 parsecs (302 ly) distant from the Sun, but is drifting closer with a radial velocity of −12.4 km/s.
Codex Sinaiticus Rescriptus, mostly originating in Saint Catherine's Monastery, Sinai from Sin. Georg. 34; Tsagareli 81, is an accumulation of nineteen Christian Palestinian Aramaic palimpsest manuscripts containing Old Testament, Gospel and Epistles pericopes of diverse Lectionaries, among them two witnesses of the Old Jerusalem Lectionary, various unidentified homilies and two by John Chrysostom, hagiographic texts as the Life of Pachomios, the Martyrdom of Philemon Martyrs, and the Catecheses by Cyril of Jerusalem. The palimpsests manuscripts are recycled parchment material that were erased and reused by the tenth century Georgian scribe Ioane-Zosime for overwriting them with homilies and a Iadgari. Part of the parchment leaves had been brought by him from the Monastery of Saint Sabas, south of Jerusalem in the Kidron Valley, when he moved to St Catherine's Monastery and became there librarian. In the nineteenth century most of the codex was removed from the monastery at two periods. C. Tischendorf took two thirds in 1855 and 1857 with the Codex Sinaiticus to St Peterburg and handed it over to the Imperial Library, now the National Library of Russia, and the remaining third left on a clandestine route [so-called collection of Dr Friedrich Grote (1862-1922)] and found its way into various European and later also into US collections, at present in a Norwegian collection. From the New Finds of 1975 in the Monastery of Saint Catherine missing folios of some of the underlying manuscripts could be retrieved, with one connected to Princeton, Garrett MS 24.
