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NGC 3754
NGC 3754 is a small barred spiral galaxy located in Leo. It is located 447 million light-years away from the Solar System and was discovered on April 5, 1874, by Ralph Copeland. The luminosity class of NGC 3754 is II and it is listed as a LINER galaxy by SIMBAD, meaning, a nucleus presenting an emission spectrum characterized by broad lines of weak ionized atoms. Copeland Septet NGC 3754 is a member of the Copeland Septet which is made up of 7 galaxies discovered by Copeland in 1874. The other members of the group, are NGC 3745, NGC 3746, NGC 3748, NGC 3750, NGC 3751 and NGC 3753. Halton Arp noticed the 7 galaxies in an article published in 1966. This group is designated as Arp 320 in which PGC 36010 is part of them. The 7 galaxies were also observed by Paul Hickson, in which he included them inside his article in 1982. This group is known as Hickson Hickson is an English surname. Notable people with the surname include: *Catherine Hickson (born 1955), Canadian volcano ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 3753
NGC 3753 is a large spiral galaxy with a bar located in the Leo constellation. It is located 435 million light-years away from the Solar System and was discovered on February 9, 1874, by Ralph Copeland. NGC 3753 is classified as a LINER galaxy meaning, it presents an emission spectrum characterized by broad lines of weak ionized atoms. It also has a luminosity class of I-II. Copeland Septet NGC 3753 is a member of the Copeland Septet which consists of 7 galaxies discovered by Copeland in 1874. The other members are NGC 3746, NGC 3745, NGC 3748, NGC 3750, NGC 3751 and NGC 3754. Halton Arp noticed the 7 galaxies in the group, in which he published the article in 1966. The group is designated as Arp 320 along another galaxy, PGC 36010. This group was observed by Paul Hickson in which he included them in his article in 1982. The group is known as Hickson Hickson is an English surname. Notable people with the surname include: *Catherine Hickson (born 1955), Canadian volcano ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellar Classification
In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction grating into a spectrum exhibiting the Continuum (spectrum), rainbow of colors interspersed with spectral lines. Each line indicates a particular chemical element or molecule, with the line strength indicating the abundance of that element. The strengths of the different spectral lines vary mainly due to the temperature of the photosphere, although in some cases there are true abundance differences. The ''spectral class'' of a star is a short code primarily summarizing the ionization state, giving an objective measure of the photosphere's temperature. Most stars are currently classified under the Morgan–Keenan (MK) system using the letters ''O'', ''B'', ''A'', ''F'', ''G'', ''K'', and ''M'', a sequence from the hottest (''O'' type) to the coo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hickson Compact Group
A Hickson Compact Group (abbreviation: HCG) is a collection of galaxies designated as published by Paul Hickson in 1982. The most famous group on Hickson's list of 100 objects is HCG 92, Stephan's Quintet. Hickson Compact Groups According to Hickson: “Most compact groups contain a high fraction of galaxies having morphological or kinematical peculiarities, nuclear radio and infrared emission, and starburst or active galactic nuclei (AGN) activity. They contain large quantities of diffuse gas and are dynamically dominated by dark matter. They most likely form as subsystems within looser associations and evolve by gravitational processes. Strong galaxy interactions result and merging is expected to lead to the ultimate demise of the group. Compact groups are surprisingly numerous, and may play a significant role in galaxy evolution.” List Gallery Image:A fossil in the making.jpg, NGC 201 is a barred spiral galaxy similar to the Milky Way, a member of HCG 7 Image:A members- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atlas Of Peculiar Galaxies
The ''Atlas of Peculiar Galaxies'' is a catalog of peculiar galaxies produced by Halton Arp in 1966. A total of 338 galaxies are presented in the atlas, which was originally published in 1966 by the California Institute of Technology. The primary goal of the catalog was to present photographs of examples of the different kinds of peculiar structures found among galaxies. (online version, including Arp's original tabular data, and PDF link) Background Arp realized that the reason why galaxies formed into spiral or elliptical shapes was not well understood. He perceived peculiar galaxies as small "experiments" that astronomers could use to understand the physical processes that distort spiral or elliptical galaxies. With this atlas, astronomers had a sample of peculiar galaxies that they could study in more detail. The atlas does not present a complete overview of every peculiar galaxy in the sky but instead provides examples of the different phenomena as observed in nearby ga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galaxy
A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. Galaxies, averaging an estimated 100 million stars, range in size from dwarfs with less than a hundred million stars, to the largest galaxies known – supergiants with one hundred trillion stars, each orbiting its galaxy's center of mass. Most of the mass in a typical galaxy is in the form of dark matter, with only a few percent of that mass visible in the form of stars and nebulae. Supermassive black holes are a common feature at the centres of galaxies. Galaxies are categorized according to their visual morphology as elliptical, spiral, or irregular. Many are thought to have supermassive black holes at their centers. The Milky Way's central black hole, known as Sagittarius A*, has a mass four million times greater than the Sun. As o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halton Arp
Halton Christian "Chip" Arp (March 21, 1927 – December 28, 2013) was an American astronomer. He was known for his 1966 ''Atlas of Peculiar Galaxies'', which (it was later theorized) catalogues many examples of interacting and merging galaxies, though Arp disputed the idea, claiming apparent associations were prime examples of ejections.Halton Arp, ''Seeing Red: Redshift, Cosmology and Academic Science'', Montreal: Aperion (1998), pp. 14, 61–62, 72, 104–105 Arp was also known as a critic of the Big Bang theory and for advocating a non-standard cosmology incorporating intrinsic redshift. Biography Arp was born on March 21, 1927, in New York City. He was married three times, has four daughters and five grandchildren. His bachelor's degree was awarded by Harvard (1949), and his PhD by Caltech (1953). Afterward he became a Fellow of the Carnegie Institution of Washington in 1953, performing research at the Mount Wilson Observatory and Palomar Observatory. Arp became a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 3751
NGC 3751 is a type E-S0 lenticular galaxy located in the Leo constellation. It is located 450 million light-years away from the Solar System and was discovered by Ralph Copeland on April 5, 1874. To date, a non-redshift measurement gives a distance of approximately 138,000 Mpc (450 million light-years) for NGC 3751. This value is within the Hubble Distance values. Copeland Septet NGC 3751 is a member of the Copeland Septet. The other members are NGC 3745, NGC 3746, NGC 3748, NGC 3750, NGC 3753 and NGC 3754. Halton Arp noticed the 7 galaxies in which he published inside his article in 1966. This group is known as Arp 320 in which another galaxy, PGC 36010 is part of it. This group was also observed by Paul Hickson, in which he included them inside his article which was published in 1982. It is noted that this group is designated as Hickson 57. NGC 3751 is known as HCG 57F.{{Cite web , title=Data from Revised NGC and IC catalogue by Wolfgang Steinicke - NGC 3700 to 3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 3748
NGC 3748 is a lenticular galaxy with a bar located in the Leo (constellation), Leo constellation. It is located 440 million light-years away from the Solar System and was discovered by Ralph Copeland on April 5, 1874, but also observed by Hermann Kobold, Lawrence Parsons, 4th Earl of Rosse, Lawrence Parsons and John Louis Emil Dreyer. Like NGC 3746, NGC 3748 also has a recessed core (RET). It is described as, "moderately bright, fairly small, slightly elongated NW-SE, 0.4'x0.3' with a small bright core". Copeland Septet NGC 3748 is a member of the Copeland Septet which is made up of 7 galaxies which were discovered by Copeland in 1874. The other members are NGC 3745, NGC 3746, NGC 3750, NGC 3751, NGC 3753 and NGC 3754. Halton Arp noticed the Galaxy, galaxies in this group in an article that was published in 1966. This group is known as Atlas of Peculiar Galaxies, Arp 320 along with another galaxy, PGC 36010. This group was observed by Paul Hickson whom he included in his art ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 3746
NGC 3746 is a large barred spiral galaxy with a ring structure located in the Leo constellation. It is located 449 million light-years from the Solar System and has an approximate diameter of 165,000 light-years. NGC 3746 was discovered by Ralph Copeland on 9 February 1874 with subsequent observations made by Hermann Kobold Hermann Kobold (5 August 1858 – 11 June 1942) was a German astronomer. Biography Hermann Albert Kobold was born in Hanover, Germany, the third of five children of the carpenter August Kobold and his wife Dorothea Kobold (née Brandt). Fro ..., Lawrence Parsons, 4th Earl of Rosse, Lawrence Parsons and John Louis Emil Dreyer. The luminosity class of NGC 3746 is II and it has a broad H II region with a recessed core (RET). Supernovae Two supernovae have been discovered in NGC 3746 so far: SN 2002ar and SN 2005ba. SN 2002ar SN 2002ar was discovered by Dr W.D. Li from the University of California, Berkeley via unfiltered CCD images which was taken b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 3745
NGC 3745 is a lenticular galaxy with a bar structure located in the constellation of Leo (constellation), Leo. NGC 3745 is located 471 million Light-year, light-years away from the Solar System and was discovered by Ralph Copeland on April 5, 1874, but also observed by Hermann Kobold, Lawrence Parsons, 4th Earl of Rosse, Lawrence Parsons and John Louis Emil Dreyer. Copeland Septet NGC 3745 is a member of the Copeland Septet. The other members of the group are NGC 3746, NGC 3748, NGC 3750, NGC 3751, NGC 3753 and NGC 3754. Halton Arp noticed the group when he published the article in 1966. The group is designated as Atlas of Peculiar Galaxies, Arp 320 in which another galaxy PGC 36010, is part of it. This group was also observed by Paul Hickson, in which he included them inside his article in 1982. This group is known as Hickson Compact Group, Hickson 57, in which NGC 3745 is designated as HCG 57G.{{Cite web , title=Data from Revised NGC and IC catalogue by Wolfgang Steinickle - N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atom
Every atom is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and a number of neutrons. Only the most common variety of hydrogen has no neutrons. Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms. Atoms are extremely small, typically around 100 picometers across. They are so small that accurately predicting their behavior using classical physics, as if they were tennis balls for example, is not possible due to quantum effects. More than 99.94% of an atom's mass is in the nucleus. The protons have a positive electric charge, the electrons have a negative electric charge, and the neutrons have no electric charge. If the number of protons and electrons are equal, then the atom is electrically neutral. If an atom has more or fewer electrons than protons, then it has an overall negative or positive charge, respectively – such atoms are called ions. The electrons of an atom are a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
