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Herschel 400
The Herschel 400 catalogue is a subset of William Herschel's original ''Catalogue of Nebulae and Clusters of Stars'', selected by Brenda F. Guzman (Branchett), Lydel Guzman, Paul Jones, James Morris, Peggy Taylor and Sara Saey of the Ancient City Astronomy Club in St. Augustine, Florida, United States 1980. They decided to generate the list after reading a letter published in ''Sky & Telescope'' by James Mullaney of Pittsburgh, Pennsylvania, United States. In this letter Mr. Mullaney suggested that William Herschel's original catalogue of 2,500 objects would be an excellent basis for deep sky object selection for amateur astronomers looking for a challenge after completing the Messier Catalogue. The Herschel 400 is a subset of John Herschel's '' General Catalogue of Nebulae and Clusters'' published in 1864 of 5,000 objects, and hence also of the ''New General Catalogue''. The catalogue forms the basis of thAstronomical League's Herschel 400 club In 1997, another subset of 400 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Herschel
Frederick William Herschel ( ; ; 15 November 1738 – 25 August 1822) was a German-British astronomer and composer. He frequently collaborated with his younger sister and fellow astronomer Caroline Herschel. Born in the Electorate of Hanover, William Herschel followed his father into the military band of Hanover, before immigrating to Kingdom of Great Britain, Britain in 1757 at the age of nineteen. Herschel constructed his first large telescope in 1774, after which he spent nine years carrying out sky surveys to investigate double stars. Herschel published catalogues of nebulae in 1802 (2,500 objects) and in 1820 (5,000 objects). The resolving power of the Herschel telescopes revealed that many objects called nebulae in the Messier object, Messier catalogue were actually clusters of stars. On 13 March 1781 while making observations he made note of a new object in the constellation of Gemini. This would, after several weeks of verification and consultation with other astrono ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 2422
Messier 47 (M47 or NGC 2422), also known as NGC 2478 is an open cluster in the mildly southern constellation of Puppis. It was discovered by Giovanni Batista Hodierna before 1654 and in his then keynote work re-discovered by Charles Messier on 1771. It was also independently discovered by Caroline Herschel. There is no cluster in the position indicated by Messier, which he expressed in terms of its right ascension and declination with respect to the star 2 Puppis. However, if the signs (+ and −) he wrote are swapped, the position matches. Until this equivalency was found, M47 was considered a lost Messier Object. This identification as the same thing (ad idem) only came in 1959 with a realization by Canadian astronomer T. F. Morris. M47 is centered about 1,600 light-year A light-year, alternatively spelled light year (ly or lyr), is a unit of length used to express astronomical distances and is equal to exactly , which is approximately 9.46 trillion km or 5.88 tri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 3992
Messier 109 (also known as NGC 3992 or the Vacuum Cleaner Galaxy) is a barred spiral galaxy exhibiting a weak inner ring structure around the central bar approximately away in the northern constellation Ursa Major. M109 can be seen south-east of the star Phecda (γ UMa, Gamma Ursa Majoris). History Messier 109 was discovered by Pierre Méchain in 1781. Two years later Charles Messier catalogued the object, as an appended object to his publication. Between the 1920s through the 1950s, it was considered that Messier objects over 103 were not official, but later the additions, further referred target objects from Méchain, became more widely accepted. David H. Levy mentions the modern 110 object catalog while Sir Patrick Moore places the limit at 104 objects but has M105 to 109 listed as addenda. By the late 1970s all 110 objects are commonly used among astronomers and remain so. General information This galaxy is the most distant object in the Messier Catalog, followed by M91. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 3556
Messier 108 (also known as NGC 3556, nicknamed the Surfboard Galaxy) is a barred spiral galaxy about 46 million light-years away from Earth in the northern constellation Ursa Major. It was discovered by Pierre Méchain in 1781 or 1782. From the Earth, this galaxy is seen almost edge-on. This galaxy is an isolated member of the Ursa Major Cloud of galaxies in the local supercluster. It has a morphological classification of type SBbc in the de Vaucouleurs system, which means it is a barred spiral galaxy with somewhat loosely wound arms. The maximum angular size of the galaxy in the optical band is 11′.1 × 4′.6, and it is inclined 75° to the line of sight. This galaxy has an estimated mass of 125 billion solar masses () and bears about 290 ± 80 globular clusters. Examination of the distribution of neutral hydrogen in this galaxy shows discrete shells of expanding gas extending for several kiloparsecs, known as H1 supershells. These may be driven by currents of dark matter, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 6171
Messier 107 or M107, also known as NGC 6171 or the Crucifix Cluster, is a very loose globular cluster in a very mildly southern part of the sky close to the equator in Ophiuchus, and is the last such object in the Messier Catalogue. Observational history, namings and guide It was discovered by Pierre Méchain in April 1782, then independently by William Herschel in 1793. Herschel's son, John, in his 1864 General Catalogue, described it as a "globular cluster of stars, large, very rich, very much compressed, round, well resolved, clearly consisting of stars". It was not until 1947 that Helen Sawyer Hogg added it and three other objects found by Méchain to the modern Catalogue, the latter having contributed several of the suggested observation objects which Messier had verified and added. The cluster is to be found 2.5° south and slightly west of the star Zeta Ophiuchi. Properties M107 is close to the galactic plane and about 20,900 light-years from Earth and from the Galactic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 4258
Messier 106 (also known as NGC 4258) is an intermediate spiral galaxy in the constellation Canes Venatici. It was discovered by Pierre Méchain in 1781. M106 is at a distance of about 22 to 25 million light-years away from Earth. M106 contains an Active galactic nucleus, active nucleus classified as a Seyfert galaxy, Type 2 Seyfert, and the presence of a central supermassive black hole has been demonstrated from Radio astronomy, radio-wavelength observations of the rotation of a Accretion disk, disk of molecular gas orbiting within the inner light-year around the black hole. NGC 4217 is a possible companion galaxy of Messier 106. Besides the two visible arms, it has two "anomalous arms" detectable using an X-ray telescope. Characteristics M106 has a water vapor megamaser (the equivalent of a laser operating in microwave instead of visible light and on a galactic scale) that is seen by the 22-GHz line of ortho-H2O that evidences dense and warm molecular gas. Water masers are usefu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 3379
Messier 105 or M105, also known as NGC 3379, is an elliptical galaxy 36.6 million light-years away in the equatorial constellation of Leo. It is the biggest elliptical galaxy in the Messier catalogue that is not in the Virgo cluster. It was discovered by Pierre Méchain in 1781, just a few days after he discovered the nearby galaxies Messier 95 and Messier 96. This galaxy is one of a few not object-verified by Messier so omitted in the editions of his Catalogue of his era. It was appended when Helen S. Hogg found a letter by Méchain locating and describing this object which matched those aspects under its first-published name, NGC 3379. It has a morphological classification of E1, indicating a standard elliptical galaxy with a flattening of 10%. The major axis is aligned along a position angle of 71°. Isophotes of the galaxy are near perfect ellipses, twisting no more than 5° out of alignment, with changes in ellipticity of no more than 0.06. There is no fine structur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 4594
The Sombrero Galaxy (also known as Messier Object 104, M104 or NGC 4594) is a peculiar galaxy of unclear classification in the constellation borders of Virgo and Corvus, being about from the Milky Way galaxy. It is a member of the Virgo II Groups, a series of galaxies and galaxy clusters strung out from the southern edge of the Virgo Supercluster. It has an isophotal diameter of approximately , making it slightly bigger in size than the Milky Way. It has a bright nucleus, an unusually large central bulge, and a prominent dust lane in its outer disk, which from Earth is viewed almost edge-on. The dark dust lane and the bulge give it the appearance of a sombrero hat (thus the name). Astronomers initially thought the halo was small and light, indicative of a spiral galaxy; but the Spitzer Space Telescope found that the halo was significantly larger and more massive than previously thought, indicative of a giant elliptical galaxy. The galaxy has an apparent magnitude of +8.0, maki ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 5866
NGC 5866 (also called the Spindle Galaxy or possibly Messier 102) is a lenticular galaxy in the constellation Draco. NGC 5866 was most likely discovered by Pierre Méchain or Charles Messier in 1781, and independently found by William Herschel in 1788. Measured orbital velocities of its globular cluster system imply that dark matter makes up only of the mass within 5 effective radii, a notable paucity. Dust lane One of the most outstanding features of NGC 5866 is the extended dust disk, which is seen almost exactly edge-on. This dust lane is highly unusual for a lenticular galaxy. The dust in most lenticular galaxies is generally found only near the nucleus and generally follows the light profile of the galaxies' bulges. This dust disk may contain a ring-like structure, although the shape of this structure is difficult to determine given the edge-on orientation of the galaxy. It is also possible that the galaxy is a spiral galaxy that was misclassified as a lenticular galax ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 4548
Messier 91 (also known as NGC 4548 or M91) is a barred spiral galaxy that is found in the south of Coma Berenices. It is in the local supercluster and is part of the Virgo Cluster of galaxies. It is about 63 million light-years away from our galaxy. It was the last of a group of eight "nebulae" – the term 'galaxy' only coming into use for these objects once it was realized in the 20th century that they were extragalactic – discovered by Charles Messier in 1781. It is the faintest object in the Messier catalog, with an apparent magnitude of 10.2. As a result of a bookkeeping error by Messier, M91 was for a long time one of the few missing entries in the Messier catalog, not matching any known object in the sky. It was not until 1969 that amateur astronomer William C. WilliamsWilliam C. WilliamsLetter Sky and Telescope, December 1969, p. 376. Accessed 13 April 2011 realized that M91 was NGC 4548,Students for the Exploration and Development of Spac Accessed online 14 A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 3034
Messier 82 (also known as NGC 3034, Cigar Galaxy or M82) is a starburst galaxy approximately 12 million light-years away in the constellation Ursa Major. It is the second-largest member of the M81 Group, with the D25 isophotal diameter of . It is about five times more luminous than the Milky Way and its central region is about one hundred times more luminous. The starburst activity is thought to have been triggered by interaction with neighboring galaxy M81. As one of the closest starburst galaxies to Earth, M82 is the prototypical example of this galaxy type. SN 2014J, a type Ia supernova, was discovered in the galaxy on 21 January 2014. In 2014, in studying M82, scientists discovered the brightest pulsar yet known, designated M82 X-2. In November 2023, a gamma-ray burst was observed in M82, which was determined to have come from a magnetar, the first such event detected outside the Milky Way (and only the fourth such event ever detected). Discovery M82, with M81, was disco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Little Dumbbell Nebula
The Little Dumbbell Nebula, also known as Messier 76, NGC 650/651, the Barbell Nebula, or the Cork Nebula, is a planetary nebula in the northern constellation of Perseus. It was discovered by Pierre Méchain in 1780 and included in Charles Messier's catalog of comet-like objects as number 76. It was first classified as a planetary nebula in 1918 by the astronomer Heber Doust Curtis. However, others might have previously recognized it as a planetary nebula; for example, William Huggins found its spectrum indicated it was a nebula (instead of a galaxy or a star cluster); and Isaac Roberts in 1891 suggested that M76 might be similar to the Ring Nebula (M57), as seen instead from the side view. M76 is currently classed as a type of bipolar planetary nebula (BPN), composed of a ring which we see edge-on as the central bar structure, and two lobes on either opening of the ring. The progenitor star ejected the ring when it was in the asymptotic giant branch, before it had become a pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
