Advertising supplements periodically accompany corresponding newspapers and are prepared by the paper's advertising staff instead of its editorial staff. It is common for them to cover topics such as real estate and automobiles on behalf of the paper's frequent advertisers.
17-454: The California Nebula (Also known NGC 1499 or Sh2 -220 ) is an emission nebula located in the constellation Perseus . Its name comes from its resemblance to the outline of the US State of California in long exposure photographs. It is almost 2.5° long on the sky and, because of its very low surface brightness , it is extremely difficult to observe visually. It can be observed with
34-454: A H α filter (isolates the H α line at 656 nm) or H β filter (isolates the H β line at 486 nm) in a rich-field telescope under dark skies. It lies at a distance of about 1,000 light years from Earth . Its fluorescence is due to excitation of the H β line in the nebula by the nearby prodigiously energetic O7 star, Xi Persei (also known as Menkib ). The California Nebula was discovered by E. E. Barnard in 1884. By coincidence,
51-518: A supplement to the NGC, and contains an additional 5,386 objects, collectively known as the IC objects. It summarizes the discoveries of galaxies, clusters and nebulae between 1888 and 1907, most of them made possible by photography . A list of corrections to the IC was published in 1912. The Revised New Catalogue of Nonstellar Astronomical Objects (abbreviated as RNGC ) was compiled by Sulentic and Tifft in
68-820: A second supplement to the General Catalogue , but the Royal Astronomical Society asked Dreyer to compile a new version instead. This led to the publication of the New General Catalogue in the Memoirs of the Royal Astronomical Society in 1888. Assembling the NGC was a challenge, as Dreyer had to deal with many contradictory and unclear reports made with a variety of telescopes with apertures ranging from 2 to 72 inches. While he did check some himself,
85-548: Is 301 objects (2.3%). The brightest star in this catalogue is NGC 771 with magnitude of 4.0. NGC 2000.0 (also known as the Complete New General Catalog and Index Catalog of Nebulae and Star Clusters ) is a 1988 compilation of the NGC and IC made by Roger W. Sinnott, using the J2000.0 coordinates. It incorporates several corrections and errata made by astronomers over the years. The NGC/IC Project
102-560: Is an astronomical catalogue of deep-sky objects compiled by John Louis Emil Dreyer in 1888. The NGC contains 7,840 objects, including galaxies , star clusters and emission nebulae . Dreyer published two supplements to the NGC in 1895 and 1908, known as the Index Catalogues (abbreviated IC ), describing a further 5,386 astronomical objects. Thousands of these objects are best known by their NGC or IC numbers, which remain in widespread use. The NGC expanded and consolidated
119-606: The NGC/IC Project in 1993. A Revised New General Catalogue and Index Catalogue (abbreviated as RNGC/IC) was compiled in 2009 by Wolfgang Steinicke and updated in 2019 with 13,957 objects. The original New General Catalogue was compiled during the 1880s by John Louis Emil Dreyer using observations from William Herschel and his son John , among others. Dreyer had already published a supplement to Herschel's General Catalogue of Nebulae and Clusters (GC), containing about 1,000 new objects. In 1886, he suggested building
136-542: The 18th and 19th centuries". It found that one of the 229—NGC 1498—was not actually in the sky. Five others were duplicates of other entries, 99 existed "in some form", and the other 124 required additional research to resolve. As another example, reflection nebula NGC 2163 in Orion was classified "non-existent" due to a transcription error by Dreyer. Dreyer corrected his own mistake in the Index Catalogues, but
153-537: The California Nebula transits in the zenith in central California as the latitude matches the declination of the object. NASA selected the California Nebula as its Astronomy Picture of the Day on October, 22, 2022, based on a submission from an amateur astronomer taken from a ground-based telescope. New General Catalogue The New General Catalogue of Nebulae and Clusters of Stars (abbreviated NGC )
170-490: The RNGC preserved the original error, and additionally reversed the sign of the declination, resulting in NGC 2163 being classified as non-existent. The Revised New General Catalogue and Index Catalogue (abbreviated as RNGC/IC ) is a compilation made by Wolfgang Steinicke in 2009. It is a comprehensive and authoritative treatment of the NGC and IC catalogues. The number of objects with status of "not found" in this catalogue
187-427: The RNGC. The designation is applied to objects which are duplicate catalogue entries, those which were not detected in subsequent observations, and a number of objects catalogued as star clusters which in subsequent studies were regarded as coincidental groupings. A 1993 monograph considered the 229 star clusters called non-existent in the RNGC. They had been "misidentified or have not been located since their discovery in
SECTION 10
#1732780605113204-604: The cataloguing work of William and Caroline Herschel , and John Herschel 's General Catalogue of Nebulae and Clusters of Stars . Objects south of the celestial equator are catalogued somewhat less thoroughly, but many were included based on observation by John Herschel or James Dunlop . The NGC contained multiple errors, but attempts to eliminate them were made by the Revised New General Catalogue (RNGC) by Jack W. Sulentic and William G. Tifft in 1973, NGC2000.0 by Roger W. Sinnott in 1988, and
221-473: The early 1970s, and was published in 1973, as an update to the NGC. The work did not incorporate several previously published corrections to the NGC data (including corrections published by Dreyer himself), and introduced some new errors. For example, the well-known compact galaxy group Copeland Septet in the Leo constellation appears as non-existent in the RNGC. Nearly 800 objects are listed as "non-existent" in
238-420: The information presented on course textbooks. These can include printed materials, CDs, websites, or other electronic materials. In academic publishing , some journals publish supplements, which often either cover an industry-funded conference or are "symposia" on a given topic. These supplements are often subsidized by an external sponsor. Such supplements can have guest editors, are often not peer-reviewed to
255-655: The objects. Supplement (publishing) Some supplements are spin-offs from a newspaper. They are sold separately and typically cover a specific topic, such as the Times Literary Supplement and the Times Educational Supplement Supplements found on some DVDs, HD DVDs, and Blu-rays are more commonly known as special features, bonus features, or bonus material. In education, supplemental materials are educational materials designed to accompany or expand on
272-667: The sheer number of objects meant Dreyer had to accept them as published by others for the purpose of his compilation. The catalogue contained several errors, mostly relating to position and descriptions, but Dreyer referenced the catalogue, which allowed later astronomers to review the original references and publish corrections to the original NGC. The first major update to the NGC is the Index Catalogue of Nebulae and Clusters of Stars (abbreviated as IC ), published in two parts by Dreyer in 1895 (IC I, containing 1,520 objects) and 1908 (IC II, containing 3,866 objects). It serves as
289-540: Was a collaboration among professional and amateur astronomers formed by Steve Gottlieb in 1990, although Steve Gottlieb already started to observe and record NGC objects as early as 1979. Other primary team members were Harold G. Corwin Jr., Malcolm Thomson, Robert E. Erdmann and Jeffrey Corder. The project was completed by 2017. This project identified all NGC and IC objects, corrected mistakes, collected images and basic astronomical data and checked all historical data related to
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