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NGC 6193
NGC 6193 (also known as Caldwell 82) is open cluster containing 27 stars in the constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The first constellati ... Ara, visible to the unaided eye. NGC 6193 lies at the center of the Ara OB1 association, which extends over a square degree. The cluster is associated with (and provides the energizing radiation for) neighboring regions of the nebulosity NGC 6188. Cluster members NGC 6193 is dominated by two O class multiple star systems within 10" of each other at the centre of the cluster, and a probable binary B0 giant. There are at least 20 other early B stars in the cluster, of 9th and 10th magnitude. Image gallery Star cluster NGC 6193 and nebula NGC 6188.jpg, Star cluster NGC 6193 and nebula NGC 6188. File:NGC_6193_map.png, Map showing the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Cluster
An open cluster is a type of star cluster made of tens to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way galaxy, and many more are thought to exist. Each one is loosely bound by mutual gravity, gravitational attraction and becomes disrupted by close encounters with other clusters and clouds of gas as they orbit the Galactic Center. This can result in a loss of cluster members through internal close encounters and a dispersion into the main body of the galaxy. Open clusters generally survive for a few hundred million years, with the most massive ones surviving for a few billion years. In contrast, the more massive globular clusters of stars exert a stronger gravitational attraction on their members, and can survive for longer. Open clusters have been found only in spiral galaxy, spiral and irregular galaxy, irregular galaxies, in which active star formatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 150136
HD 150136 is a multiple star system in the southern constellation of Ara, around 4,300 light years away. It is the brightest member of the faint open cluster NGC 6193, part of the Ara OB1 association. System HD 150136 is listed in the Washington Double Star Catalog as having seven visual components within . Component A is a close triple system containing three massive class O main sequence stars. The brightest companion is catalogued individually as HD 150135 as well as component C of the multiple system, separated by only 10 arcseconds. It is another O class spectroscopic binary and also a member of NGC 6193. The other catalogued components are all 10th to 12th magnitude, similar to many other stars known to be members of NGC 6193. The primary star consists of a double-lined spectroscopic binary with a more distant tertiary companion. The third star is orbiting the other two with a period of 8.2 years, an eccentricity of 0.73, and an inclination of 108° ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apparent Magnitude
Apparent magnitude () is a measure of the Irradiance, brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction (astronomy), extinction of the object's light caused by interstellar dust along the sightline, line of sight to the observer. Unless stated otherwise, the word ''magnitude'' in astronomy usually refers to a celestial object's apparent magnitude. The magnitude scale likely dates to before the ancient Ancient Greek astronomy#Astronomy in the Greco-Roman and Late Antique eras, Roman astronomer Ptolemy, Claudius Ptolemy, whose Star catalogue, star catalog popularized the system by listing stars from First-magnitude star, 1st magnitude (brightest) to 6th magnitude (dimmest). The modern scale was mathematically defined to closely match this historical system by Norman Robert Pogson, Norman Pogson in 1856. The scale is reverse logarithmic scale, logarithmic: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Declination
In astronomy, declination (abbreviated dec; symbol ''δ'') is one of the two angles that locate a point on the celestial sphere in the equatorial coordinate system, the other being hour angle. The declination angle is measured north (positive) or south (negative) of the celestial equator, along the hour circle passing through the point in question. The root of the word ''declination'' (Latin, ''declinatio'') means "a bending away" or "a bending down". It comes from the same root as the words ''incline'' ("bend forward") and ''recline'' ("bend backward"). In some 18th and 19th century astronomical texts, declination is given as ''North Pole Distance'' (N.P.D.), which is equivalent to 90 – (declination). For instance an object marked as declination −5 would have an N.P.D. of 95, and a declination of −90 (the south celestial pole) would have an N.P.D. of 180. Explanation Declination in astronomy is comparable to geographic latitude, projected onto the celestial sphere, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Right Ascension
Right ascension (abbreviated RA; symbol ) is the angular distance of a particular point measured eastward along the celestial equator from the Sun at the equinox (celestial coordinates), March equinox to the (hour circle of the) point in question above the Earth. When paired with declination, these celestial coordinate system, astronomical coordinates specify the location of a point on the celestial sphere in the equatorial coordinate system. An old term, ''right ascension'' (), "''Ascensio recta'' Solis, stellæ, aut alterius cujusdam signi, est gradus æquatorus cum quo simul exoritur in sphæra recta"; roughly translated, "''Right ascension'' of the Sun, stars, or any other sign, is the degree of the equator that rises together in a right sphere" refers to the ''ascension'', or the point on the celestial equator that rises with any celestial object as seen from Earth's equator, where the celestial equator perpendicular, intersects the horizon at a right angle. It contrasts wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 6188
NGC 6188, also known as the Firebird Nebula, is an emission nebula located about 4,000 light years away in the constellation Ara (constellation), Ara. The bright open cluster NGC 6193, visible to the naked eye, is responsible for a region of reflection nebulosity within NGC 6188. NGC 6188 is a star forming nebula, and is sculpted by the massive, young stars that have recently formed there – some are only a few million years old. This spark of formation was probably caused when the last batch of stars went supernova. References External links * * NGC objects, 6188 Emission nebulae Star-forming regions Ara (constellation) {{nebula-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HarperCollins
HarperCollins Publishers LLC is a British–American publishing company that is considered to be one of the "Big Five (publishers), Big Five" English-language publishers, along with Penguin Random House, Hachette Book Group USA, Hachette, Macmillan Publishers, Macmillan, and Simon & Schuster. HarperCollins is headquartered in New York City and London and is a subsidiary of News Corp. The company's name is derived from a combination of the firm's predecessors. Harper & Brothers, founded in 1817 in New York, merged with Row, Peterson & Company in 1962 to form Harper & Row, which was acquired by News Corp in 1987. The Scotland, Scottish publishing company William Collins, Sons, founded in 1819 in Glasgow, was acquired by News Corp in 1987 and merged with Harper & Row to form HarperCollins. The logo for the firm combines the fire from Harper's torch and the water from Collins' fountain. HarperCollins operates publishing groups in the United States, Canada, the United Kingdom, Austr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The first constellations were likely defined in prehistory. People used them to relate stories of their beliefs, experiences, creation myth, creation, and mythology. Different cultures and countries invented their own constellations, some of which lasted into the early 20th century before today's constellations were internationally recognized. The recognition of constellations has changed significantly over time. Many changed in size or shape. Some became popular, only to drop into obscurity. Some were limited to a single culture or nation. Naming constellations also helped astronomers and navigators identify stars more easily. Twelve (or thirteen) ancient constellations belong to the zodiac (straddling the ecliptic, which the Sun, Moon, and planets all traver ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caldwell Catalog
The Caldwell catalogue is an astronomical catalogue of 109 star clusters, nebulae, and galaxies for observation by amateur astronomers. The list was compiled by Patrick Moore as a complement to the Messier catalogue. While the Messier catalogue is used by amateur astronomers as a list of deep-sky objects for observation, Moore noted that Messier's list was not compiled for that purpose and excluded many of the sky's brightest deep-sky objects, such as the Hyades, the Double Cluster (NGC 869 and NGC 884), and the Sculptor Galaxy (NGC 253). The Messier catalogue was actually compiled as a list of known objects that might be confused with comets. Moore also observed that since Messier compiled his list from observations in Paris, it did not include bright deep-sky objects visible in the Southern Hemisphere, such as Omega Centauri, Centaurus A, the Jewel Box, and 47 Tucanae. Moore compiled a list of 109 objects to match the commonly accepted number of Messier objects (he excluded ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
J2000
In astronomy, an epoch or reference epoch is a moment in time used as a reference point for some time-varying astronomical quantity. It is useful for the celestial coordinates or orbital elements of a celestial body, as they are subject to perturbations and vary with time. These time-varying astronomical quantities might include, for example, the mean longitude or mean anomaly of a body, the node of its orbit relative to a reference plane, the direction of the apogee or aphelion of its orbit, or the size of the major axis of its orbit. The main use of astronomical quantities specified in this way is to calculate other relevant parameters of motion, in order to predict future positions and velocities. The applied tools of the disciplines of celestial mechanics or its subfield orbital mechanics (for predicting orbital paths and positions for bodies in motion under the gravitational effects of other bodies) can be used to generate an ephemeris, a table of values giving ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
