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Orion–Cygnus Arm
The Orion Arm, also known as the Orion–Cygnus Arm, is a minor spiral arm within the Milky Way Galaxy spanning in width and extending roughly in length. This galactic structure encompasses the Solar System, including Earth. It is sometimes referred to by alternate names such as the Local Arm or Orion Bridge, and it was previously identified as the Local Spur or the Orion Spur. It should not be confused with the outer terminus of the Norma Arm, known as the Cygnus Arm. Naming and brightness The arm is named after the Orion Constellation, one of the most prominent constellations of the Northern Hemisphere in winter (or the Southern Hemisphere in summer). Some of the brightest stars in the sky as well as other well-known celestial objects of the constellation (e.g. Betelgeuse, Rigel, the three stars of Orion's Belt, and the Orion Nebula) are found within it, as shown on Orion Arm's interactive map. Location The Orion arm is located between the Carina–Sagittarius Arm, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milky Way Arms Ssc2008-10
Milky is an Italian dance music production group consisting of producers Giordano Trivellato and Giuliano Sacchetto, with Italian singer Giuditta serving as their lead singer on their album ''Star''. Although Giuditta Gazza was the singer on the recordings, a model, the Egyptian-born and German-raised Sabrina Elahl, was used for the music video for the "Just the Way You Are (Milky song), Just the Way You Are" single. The same model was used for the gramophone record, vinyl cover. Elahl's voice did not appear on any of Milky's recordings, where all songs were sung by Giuditta. Giuditta can be seen on the "Be My World" twelve-inch single, 12" cover as well as in the video for "In My Mind". Two of the tracks from ''Star'' eventually became hits in the United States; "Just the Way You Are" reached the chart-topper, nu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astrophysical Maser
An astrophysical maser is a naturally occurring source of Stimulated emission, stimulated spectral line emission, typically in the microwave portion of the electromagnetic spectrum. This emission may arise in molecular clouds, comets, planetary atmospheres, stellar atmospheres, or various other conditions in interstellar space. Background Discrete transition energy Like a laser, the emission from a maser is Stimulated emission, stimulated (or ''seeded'') and monochromatic, having the frequency Max Planck, corresponding to the energy difference between two Quantum mechanics, quantum-mechanical energy levels of the species in the gain medium which have been Laser pumping, pumped into a Statistical mechanics, non-thermal Population inversion, population distribution. However, naturally occurring masers lack the resonance, resonant Cavity resonator, cavity engineered for terrestrial laboratory masers. The emission from an astrophysical maser is due to a single pass through the gain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winnecke 4
Winnecke 4 (also known as Messier 40 or WNC 4) is an optical double star consisting of two unrelated stars in a northerly zone of the sky, Ursa Major. The pair were discovered by Charles Messier in 1764 while he was searching for a nebula that had been reported in the area by Johannes Hevelius. Not seeing any nebulae, Messier catalogued this apparent pair instead. The pair were rediscovered by Friedrich August Theodor Winnecke in 1863, and included in the Winnecke Catalogue of Double Stars as number 4. Burnham calls M40 "one of the few real mistakes in the Messier catalog," faulting Messier for including it when all he saw was a double star, not a nebula of any sort. In 1991 the separation between the components was measured at 51.7 ″, an increase since 1764. Data gathered by astronomers Brian Skiff (2001) and Richard L. Nugent (2002) strongly suggested the subject was merely an optical double star rather than a physically connected (binary) system. The A star ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Messier 39
Messier 39 or M39, also known as NGC 7092, is an open cluster of stars in the constellation of Cygnus (constellation), Cygnus, sometimes referred to as the Pyramid Cluster. It is positioned two degrees south of the star Pi Cygni and around 9° east-northeast of Deneb. The cluster was discovered by Guillaume Le Gentil in 1749, then Charles Messier added it to his catalogue in 1764. When observed in a small telescope at low power the cluster shows around two dozen members but is best observed with binoculars. It has a total integrated magnitude (astronomy), magnitude (brightness) of 4.6 and spans an angular diameter of – about the size of the full Moon. It is centered about away. This cluster has an estimated mass of and a linear tidal radius (cluster), tidal radius of . Of the 15 brightest components, six form binary star systems; one more is suspected. Henry Draper Catalogue, HD 205117 is a probable eclipsing binary system with a period of 113.2 days that varies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Messier 35
Messier 35 or M35, also known as NGC 2168 or the Shoe-Buckle Cluster, is a relatively close open cluster of stars in the west of Gemini, at about the declination of the Sun when the latter is at June solstice. It was discovered by Philippe Loys de Chéseaux around 1745 and independently discovered by John Bevis before 1750. It is scattered over part of the sky almost the size of the full moon and is away. The compact open cluster NGC 2158 lies directly southwest of it. Leonard & Merritt (1989) computed the mass of M35 using a statistical technique based on proper motion velocities of its stars. The mass within the central was found to be between 1600 and 3200 solar masses, consistent with the mass of a realistic stellar population within the same radius. Bouy et al. in 2015 found a mass of around within the central . There are 305 stars that can be intrinsically shown to be extremely likely to be members, and up to 4,349 averaging the 50% membership probability, from the k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Messier 34
Messier 34 (also known as M34, NGC 1039, or the Spiral Cluster) is a large and relatively near open cluster in Perseus. It was probably discovered by Giovanni Batista Hodierna before 1654 and included by Charles Messier in his catalog of comet-like objects in 1764. Messier described it as, "A cluster of small stars a little below the parallel of γ (Andromedae). In an ordinary telescope of 3 feet one can distinguish the stars." Based on the distance modulus of 8.38, it is about away. For stars ranging from 0.12 to 1 solar mass (), the cluster has about 400. It spans about 35′ on the sky which translates to a true radius of 7.5 light years at such distance. The cluster is just visible to the naked eye in very dark conditions, well away from city lights. It is possible to see it in binoculars when light pollution is low. The age of this cluster lies between the ages of the Pleiades open cluster at 100 million years and the Hyades open cluster at 800 million years. Specificall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Messier 29
Messier 29 or M29, also known as NGC 6913 or the Cooling Tower Cluster, is a quite small, bright open cluster of stars just south of the central bright star Gamma Cygni of a northerly zone of the sky, Cygnus. It was discovered by Charles Messier in 1764, and can be seen from Earth by using binoculars. M29 is well within the several degrees of the arms and bulge of the Milky Way. It is at least many hundreds of light years short of the yardstick distance to the Galactic Center, as is between 4,000Kenneth Glyn Jones (ed.) ''The Sky Catalogue 2000.0'' and 7,200 light years away.Preferred by most sources including Mallas/Kreimer and Burnham, and agreeing with early estimates or R.J. Trumpler 1930 A 1998 popular work gives a value within this range.Kepple, George Robert., Sanner, Glen W.. The Night Sky Observer's Guide: Spring & summer. United States: Willmann-Bell, 1998 at Chapter 42. Cygnus, The Swan Data from Gaia EDR3 gives a parallactic distance of about 5,240 light year ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dumbbell Nebula
The Dumbbell Nebula (also known as the Apple Core Nebula, Messier 27, and NGC 6853) is a planetary nebula (nebulosity surrounding a white dwarf) in the constellation Vulpecula, at a distance of about 1360 light-years. It was the first such nebula to be discovered, by Charles Messier in 1764. At its brightness of visual magnitude 7.5 and diameter of about 8 arcminutes, it is easily visible in binoculars and is a popular observing target in amateur astronomy, amateur telescopes. The Dumbbell Nebula appears shaped like a prolate spheroid and is viewed from our perspective along the plane of its equator. In 1992, Moreno-Corral et al. computed that its rate of expansion angularly was, viewed from our distance, no more than (″) per century. From this, an upper limit to the age of 14,600 years may be determined. In 1970, Bohuski, Smith, and Weedman found an expansion velocity of . Given its semi-minor axis radius of , this implies that the kinematic age of the nebula is 9,800 years. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Messier 25
Messier 25, also known as IC 4725, is an open cluster of stars in the southern constellation of Sagittarius. The first recorded observation of this cluster was made by Philippe Loys de Chéseaux in 1745 and it was included in Charles Messier's list of nebulous objects in 1764. The cluster is located near some obscuring features, with a dark lane passing near the center. M25 is at a distance of about away from Earth and is 67.6 million years old. The spatial dimension of this cluster is about across. It has an estimated mass of , of which about 24% is interstellar matter. A Delta Cephei type variable star designated '' U Sagittarii'' is a member of this cluster, as are two red giants, one of which is a binary system. New research indicates M25 may constitute a ternary star cluster together with NGC 6716 and Collinder 394. See also * List of Messier objects The Messier objects are a set of 110 astronomical objects catalogued by the French astronomer Charles Messier ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Messier 23
Messier 23, also known as NGC 6494, is an open cluster of stars in the northwest of the southern constellation of Sagittarius. It was discovered by Charles Messier in 1764. It can be found in good conditions with binoculars or a modestly sized telescope. It is in front of "an extensive gas and dust network", which there may be no inter-association. It is within 5° the sun's position (namely in mid-December) so can be occulted by the moon. The cluster is centered about 2,050 light years away. Estimates for the number of its members range from 169 up to 414, with a directly-counted mass of ; by application of the virial theorem. The cluster is around 330 million years old with a near-solar metallicity of e/H= −0.04. The brightest component (lucida) is of magnitude 9.3. Five of the cluster members are candidate red giants, while orange variable VV Sgr in the far south, is a candidate asymptotic giant branch star. A 6th-magnitude star, shown in the top-right co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ptolemy Cluster
Messier 7 or M7, also designated NGC 6475 and sometimes known as the Ptolemy Cluster, is an open cluster of stars in the constellation of Scorpius. The cluster is easily detectable with the naked eye, close to the "stinger" of Scorpius. With a declination of −34.8°, it is the southernmost Messier object. M7 has been known since antiquity; it was first recorded by the 2nd-century Greek-Roman astronomer Ptolemy, who described it as a nebula in 130 AD. Italian astronomer Giovanni Batista Hodierna observed it before 1654 and counted 30 stars in it. In 1764, French astronomer Charles Messier catalogued the cluster as the seventh member in his list of comet-like objects. English astronomer John Herschel described it as "coarsely scattered clusters of stars". Telescopic observations of the cluster reveal about 80 stars within a field of view of 1.3° across. At the cluster's estimated distance of 980 light years this corresponds to an actual diameter of 25 light years. The tid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Butterfly Cluster
The Butterfly Cluster (cataloged as Messier 6 or M6, and as NGC 6405) is an open cluster of stars in the southern constellation of Scorpius. Its name derives from the resemblance of its shape to a butterfly. The first astronomer to record the Butterfly Cluster's existence was Giovanni Battista Hodierna in 1654. However, Robert Burnham Jr. has proposed that the 2nd century astronomer Ptolemy may have seen it with the naked eye while observing its neighbor the Ptolemy Cluster (M7). Credit for the discovery is usually given to Jean-Philippe Loys de Chéseaux in 1746. Charles Messier observed the cluster on May 23, 1764, and added it to his Messier Catalog. Estimates of the Butterfly Cluster's distance have varied over the years. Wu et al. (2009) found a distance estimate of , giving it a spatial dimension of some 12 light years. Modern measurements show its total visual brightness to be magnitude 4.2. The cluster is estimated to be 94.2 million years old. Cluster members sho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
