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Arp 148
Mayall's Object (also classified under the Atlas of Peculiar Galaxies as Arp 148) is the result of two colliding galaxies located 500 million light years away within the constellation of Ursa Major. It was discovered by American astronomer Nicholas U. Mayall of the Lick Observatory on 13 March 1940, using the Crossley reflector. When first discovered, Mayall's Object was described as a peculiar nebula, shaped like a question mark. Originally theorized to represent a galaxy reacting with the intergalactic medium, it is now thought to represent the collision of two galaxies, resulting in a new object consisting of a ring-shaped galaxy with a tail emerging from it. It is thought that the collision between the two galaxies created a shockwave that initially drew matter into the center which then formed the ring. Arp 148 was imaged by the Hubble Space Telescope as part of a survey of what are thought to be colliding galaxies. The image was taken with Wide Field and Planetary Camera 2 i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hubble Space Telescope
The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versatile, renowned both as a vital research tool and as a public relations boon for astronomy. The Hubble telescope is named after astronomer Edwin Hubble and is one of NASA's Great Observatories. The Space Telescope Science Institute (STScI) selects Hubble's targets and processes the resulting data, while the Goddard Space Flight Center (GSFC) controls the spacecraft. Hubble features a mirror, and its five main instruments observe in the ultraviolet, visible, and near-infrared regions of the electromagnetic spectrum. Hubble's orbit outside the distortion of Earth's atmosphere allows it to capture extremely high-resolution images with substantially lower background light than ground-based telescopes. It has recorded some of the most detaile ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Irregular Galaxy
An irregular galaxy is a galaxy that does not have a distinct regular shape, unlike a spiral or an elliptical galaxy. Irregular galaxies do not fall into any of the regular classes of the Hubble sequence, and they are often chaotic in appearance, with neither a nuclear bulge nor any trace of spiral arm structure. Collectively they are thought to make up about a quarter of all galaxies. Some irregular galaxies were once spiral or elliptical galaxies but were deformed by an uneven external gravitational force. Irregular galaxies may contain abundant amounts of gas and dust. This is not necessarily true for dwarf irregulars. Irregular galaxies are commonly small, about one tenth the mass of the Milky Way galaxy. Due to their small sizes, they are prone to environmental effects like crashing with large galaxies and intergalactic clouds. Types There are three major types of irregular galaxies: * An Irr-I galaxy (Irr I) is an irregular galaxy that features some structure but not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ring Galaxies
A ring galaxy is a galaxy with a circle-like appearance. Hoag's Object, discovered by Art Hoag in 1950, is an example of a ring galaxy. The ring contains many massive, relatively young blue stars, which are extremely bright. The central region contains relatively little luminous matter. Some astronomers believe that ring galaxies are formed when a smaller galaxy passes through the center of a larger galaxy. Because most of a galaxy consists of empty space, this "collision" rarely results in any actual collisions between stars. However, the gravitational disruptions caused by such an event could cause a wave of star formation to move through the larger galaxy. Other astronomers think that rings are formed around some galaxies when external accretion takes place. Star formation would then take place in the accreted material because of the shocks and compressions of the accreted material. Formation theories Ring galaxies are theorized to be formed through various methods includi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interacting Galaxies
Interacting galaxies (''colliding galaxies'') are galaxies whose gravitational fields result in a disturbance of one another. An example of a minor interaction is a satellite galaxy disturbing the primary galaxy's spiral arms. An example of a major interaction is a galactic collision, which may lead to a galaxy merger. Satellite interaction A giant galaxy interacting with its satellites is common. A satellite's gravity could attract one of the primary's spiral arms. Alternatively, the secondary satellite can dive into the primary galaxy, as in the Sagittarius Dwarf Elliptical Galaxy diving into the Milky Way. That can possibly trigger a small amount of star formation. Such orphaned clusters of stars were sometimes referred to as "blue blobs" before they were recognized as stars. Galaxy collision Colliding galaxies are common during galaxy evolution. The extremely tenuous distribution of matter in galaxies means these are not collisions in the traditional sense of the w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ursa Major (constellation)
Ursa Major (; also known as the Great Bear) is a constellation in the northern sky, whose associated mythology likely dates back into prehistory. Its Latin name means "greater (or larger) bear," referring to and contrasting it with nearby Ursa Minor, the lesser bear. In antiquity, it was one of the original 48 constellations listed by Ptolemy in the 2nd century AD, drawing on earlier works by Greek, Egyptian, Babylonian, and Assyrian astronomers. Today it is the third largest of the 88 modern constellations. Ursa Major is primarily known from the asterism of its main seven stars, which has been called the "Big Dipper," "the Wagon," "Charles's Wain," or "the Plough," among other names. In particular, the Big Dipper's stellar configuration mimics the shape of the "Little Dipper." Two of its stars, named Dubhe and Merak ( α Ursae Majoris and β Ursae Majoris), can be used as the navigational pointer towards the place of the current northern pole star, Polaris in Ursa Mino ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Hubble Anniversary Images
This is a list of images released to celebrate the Hubble Space Telescope's anniversaries. They celebrate its "birthday" when it was launched into orbit on April 24, 1990, by the crew of Space Shuttle ''Discovery''. 15th (2005) The 15th anniversary, in 2005, was celebrated with a collection of images of M51 (the Whirlpool Galaxy), and also with a section of the Eagle nebula. The 15th anniversary included a collection of other content including, in multiple languages, the video release, ''Hubble — 15 Years of Discovery''. 17th (2007) The 17th-anniversary celebration featured a panorama of part of the Carina Nebula, and a collection of images selected from that area. 18th (2008) 59 images of merging galaxies were released for the 18th anniversary on 24 April 2008. 19th (2009) 20th (2010) 21st (2011) 22nd (2012) 23rd (2013) 24th (2014) 25th (2015) 26th (2016) 27th (2017) 28th (2018) 29th (2019) In April 2019, a special celebration image of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andromeda–Milky Way Collision
The Andromeda–Milky Way collision is a galactic collision predicted to occur in about 4.5 billion years between the two largest galaxies in the Local Group—the Milky Way (which contains the Solar System and Earth) and the Andromeda Galaxy. The stars involved are sufficiently far apart that it is improbable that any of them will individually collide. Some stars will be ejected from the resulting galaxy, often nicknamed ''Milkomeda'' or ''Milkdromeda'', a portmanteau of the respective galaxy names. Certainty The Andromeda Galaxy is approaching the Milky Way at about as indicated by blueshift. However, the lateral speed (measured as proper motion) is very difficult to measure with sufficient precision to draw reasonable conclusions. Until 2012, it was not known whether the possible collision was definitely going to happen or not. Researchers then used the Hubble Space Telescope to measure the positions of stars in Andromeda in 2002 and 2010, relative to hundreds of distant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 2207 And IC 2163
__NOTOC__ NGC 2207 and IC 2163 are a pair of colliding spiral galaxies about 80 million light-years away in the constellation Canis Major. Both galaxies were discovered by John Herschel in 1835. The larger spiral, NGC 2207, is classified as an intermediate spiral galaxy exhibiting a weak inner ring structure around the central bar. The smaller companion spiral, IC 2163, is classified as a barred spiral galaxy that also exhibits a weak inner ring and an elongated spiral arm that is likely being stretched by tidal forces with the larger companion. Both galaxies contain a vast amount of dust and gas, and are beginning to exhibit enhanced rates of star formation, as seen in infrared images. NGC 2207 is in the process of colliding and merging with IC 2163. But unlike the Antennae or the Mice Galaxies, they are still two separate spiral galaxies. They are only in the first step of colliding and merging, with NGC 2207 being in the process of tidally stripping IC 2163. Soon they will c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mayall II
Mayall II, also known as NGC-224-G1, SKHB 1, GSC 2788:2139, HBK 0-1, M31GC J003247+393440 or Andromeda's Cluster, is a globular cluster orbiting M31, the Andromeda Galaxy. It is located from the Andromeda Galaxy's galactic core, and is the brightest (by absolute magnitude) globular cluster in the Local Group, having an apparent magnitude of 13.81 in V band. Mayall II is considered to have twice the mass of Omega Centauri, and may contain a central, intermediate-mass (∼ 2 M⊙) black hole. It was first identified as a possible globular cluster by American astronomers Nicholas Mayall and Olin J. Eggen in 1953 using a Palomar Schmidt plate exposed in 1948. Because of the widespread distribution of metallicity, indicating multiple star generations and a large stellar creation period, many contend that it is not a true globular cluster, but is actually the galactic core that remains of a dwarf galaxy consumed by Andromeda. Origin of names * Mayall II is named after Nichola ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peculiar Galaxy
A peculiar galaxy is a galaxy of unusual size, shape, or composition. Between five and ten percent of known galaxies are categorized as peculiar. Astronomers have identified two types of peculiar galaxies: ''interacting galaxies'' and ''active galactic nuclei'' (AGN). When two galaxies come close to each other, their mutual gravitational forces can cause them to acquire highly irregular shapes. The terms 'peculiar galaxy' and 'interacting galaxy' have now become synonymous because the majority of peculiar galaxies attribute their forms to such gravitational forces. Formation Scientists hypothesize that many peculiar galaxies are formed by the collision of two or more galaxies. As such, peculiar galaxies tend to host more active galactic nuclei than normal galaxies, indicating that they contain supermassive black holes. Many peculiar galaxies experience starbursts, or episodes of rapid star formation, due to the galaxies merging. The periods of elevated star formation and the l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interacting Galaxy
Interacting galaxies (''colliding galaxies'') are galaxies whose gravitational fields result in a disturbance of one another. An example of a minor interaction is a satellite galaxy disturbing the primary galaxy's spiral arms. An example of a major interaction is a galactic collision, which may lead to a galaxy merger. Satellite interaction A giant galaxy interacting with its satellites is common. A satellite's gravity could attract one of the primary's spiral arms. Alternatively, the secondary satellite can dive into the primary galaxy, as in the Sagittarius Dwarf Elliptical Galaxy diving into the Milky Way. That can possibly trigger a small amount of star formation. Such orphaned clusters of stars were sometimes referred to as "blue blobs" before they were recognized as stars. Galaxy collision Colliding galaxies are common during galaxy evolution. The extremely tenuous distribution of matter in galaxies means these are not collisions in the traditional sense of the wor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
