Giuseppe Donatiello | |
|---|---|
 Giuseppe Donatiello (2017) | |
| Born | December 14, 1967 Italy |
| Occupation | Amateur astronomer |
| Notes | |
Discoverer of eleven nearby dwarf galaxies in the Local Volume | |
Giuseppe Donatiello (born 14 December 1967) is an Italian amateur astronomer. He is primarily known as the discoverer of eleven nearby dwarf galaxies in the Local Volume. [1] [2]
To these discoveries must be added some candidate planetary nebulae [23] and the participation in the discovery and analysis of several dozen stellar streams [24] [25]
He is the principal investigator and coordinator of the National Deep Sky Research Section of the Italian Amateur Astronomers Union [26]
The Local Group is the galaxy group that includes the Milky Way, where Earth is located. It has a total diameter of roughly 3 megaparsecs (10 million light-years; 9×1019 kilometres), and a total mass of the order of 2×1012 solar masses (4×1042 kg). It consists of two collections of galaxies in a "dumbbell" shape; the Milky Way and its satellites form one lobe, and the Andromeda Galaxy and its satellites constitute the other. The two collections are separated by about 800 kiloparsecs (3×106 ly; 2×1019 km) and are moving toward one another with a velocity of 123 km/s. The group itself is a part of the larger Virgo Supercluster, which may be a part of the Laniakea Supercluster. The exact number of galaxies in the Local Group is unknown as some are occluded by the Milky Way; however, at least 80 members are known, most of which are dwarf galaxies.
The Triangulum Galaxy is a spiral galaxy 2.73 million light-years (ly) from Earth in the constellation Triangulum. It is catalogued as Messier 33 or NGC (New General Catalogue) 598. With the D25 isophotal diameter of 18.74 kiloparsecs (61,100 light-years), the Triangulum Galaxy is the third-largest member of the Local Group of galaxies, behind the Andromeda Galaxy and the Milky Way.
NGC 404 is a field galaxy located about 10 million light years away in the constellation Andromeda. It was discovered by William Herschel in 1784, and is visible through small telescopes. NGC 404 lies just beyond the Local Group and does not appear gravitationally bound to it. It is located within 7 arc-minutes of second magnitude star Mirach, making it a difficult target to observe or photograph and granting it the nickname "Mirach's Ghost".
A dwarf galaxy is a small galaxy composed of about 1000 up to several billion stars, as compared to the Milky Way's 200–400 billion stars. The Large Magellanic Cloud, which closely orbits the Milky Way and contains over 30 billion stars, is sometimes classified as a dwarf galaxy; others consider it a full-fledged galaxy. Dwarf galaxies' formation and activity are thought to be heavily influenced by interactions with larger galaxies. Astronomers identify numerous types of dwarf galaxies, based on their shape and composition.
Messier 110, or M110, also known as NGC 205, is a dwarf elliptical galaxy that is a satellite of the Andromeda Galaxy in the Local Group.
A dark galaxy is a hypothesized galaxy with no stars. They received their name because they have no visible stars but may be detectable if they contain significant amounts of gas. Astronomers have long theorized the existence of dark galaxies, but there are no confirmed examples to date. Dark galaxies are distinct from intergalactic gas clouds caused by galactic tidal interactions, since these gas clouds do not contain dark matter, so they do not technically qualify as galaxies. Distinguishing between intergalactic gas clouds and galaxies is difficult; most candidate dark galaxies turn out to be tidal gas clouds. The best candidate dark galaxies to date include HI1225+01, AGC229385, and numerous gas clouds detected in studies of quasars.
NGC 278 is an isolated spiral galaxy in the northern circumpolar constellation of Cassiopeia, near the southern constellation boundary with Andromeda. It lies at a distance of approximately 39 megalight-years from the Milky Way, giving it a physical scale of 190 ly (58 pc) per arcsecond. The galaxy was discovered on December 11, 1786 by German-born astronomer William Herschel. J. L. E. Dreyer described it as, "considerably bright, pretty large, round, 2 stars of 10th magnitude near".
Pisces II is a dwarf spheroidal galaxy situated in the Pisces constellation and discovered in 2010 in the data obtained by the Sloan Digital Sky Survey. The galaxy is located at the distance of about 180 kpc (kiloparsecs) from the Sun. It is classified as a dwarf spheroidal galaxy (dSph) meaning that it has an elongated shape with the half-light radius of about 60 pc and ratio of the axis of about 5:3.
NGC 3669 is a barred spiral galaxy in the constellation Ursa Major. It was discovered by William Herschel on March 18, 1790. The galaxy is seen edge-on and appears to be slightly warped. It has a small bulge.
Robert Jay GaBany is an American amateur astronomer and astrophotographer who is also known for his work with an international team of astrophysicists led by Dr. David Martínez-Delgado. GaBany helped pioneer the use of modest size telescopes and off the shelf CCD-cameras to produce long exposure images that revealed ancient galactic merger remnants in the form of star streams surrounding nearby galaxies that were previously undetected or suspected.
NGC 922 is a peculiar galaxy in the southern constellation of Fornax, located at a distance of 142 Mly from the Milky Way. It is one of the nearest known collisional galaxies. This object was described by the Herschels as "considerably faint, pretty large, round, gradually pretty much brighter middle." The general form is described by the morphological classification of SB(s)cd pec, which indicates a peculiar (pec) barred spiral galaxy (SB) with no inner ring system around the bar (s) and loosely-wound spiral arms (cd).
NGC 4660 is an elliptical galaxy located about 63 million light-years away in the constellation Virgo. The galaxy was discovered by astronomer William Herschel on March 15, 1784 and is a member of the Virgo Cluster.
NGC 536 is a barred spiral galaxy located in the constellation Andromeda. It is located at a distance of circa 200 million light-years from Earth, which, given its apparent dimensions, means that NGC 536 is about 180,000 light years across. It was discovered by William Herschel on September 13, 1784. It is a member of Hickson Compact Group 10, which also includes the galaxies NGC 529, NGC 531, and NGC 542. It belongs to the Perseus–Pisces Supercluster.
Donatiello I, also known as Mirach's Goblin, is a dwarf spheroidal galaxy in the constellation Andromeda, located between 8.1 and 11.4 million light-years from Earth. It is a possible satellite galaxy of the dwarf lenticular galaxy NGC 404, "Mirach's Ghost", which is situated 60 arcminutes away. It is otherwise one of the most isolated dwarf spheroidal galaxies known, being separated from NGC 404 by around 211,000 light-years. The galaxy is named after its discoverer, amateur astronomer and astrophotographer Giuseppe Donatiello, who sighted the galaxy in a 2016 review of his archival long exposures from 2010 and 2013. Follow-up observations with the Roque de los Muchachos Observatory led to a scientific paper on its discovery being published in December 2018.
NGC 7492 is a globular cluster in the constellation Aquarius. It was discovered by the astronomer William Herschel on September 20, 1786. It resides in the outskirts of the Milky Way, about 80,000 light-years away, more than twice the distance between the Sun and the center of the galaxy, and is a benchmark member of the outer galactic halo. The cluster is immersed in, but does not kinematically belong to, the Sagittarius Stream.
DGSAT I is a quenched, ultra diffuse galaxy (UDG) located on the outskirts of the Pisces-Perseus Supercluster, identified in 2016 during a visual inspection of a full color image of the Andromeda II dwarf galaxy. DGSAT I resides in a low-density environment compared to the densities where UDGs are typically found. Its chemical makeup have led astronomers to propose it was formed during the dawn of the universe when galaxies emerged in a different environment than today.