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IPTF14hls
iPTF14hls is an unusual supernova star that erupted continuously for about 1,000 days beginning in September 2014 before becoming a Supernova remnant, remnant nebula. It had previously erupted in 1954. None of the theories nor proposed hypotheses fully explain all the aspects of the object. Observations The star iPTF14hls was discovered in September 2014 by the Intermediate Palomar Transient Factory, and it was first made public in November 2014 by the Catalina Real-time Transient Survey, CRTS survey as CSS141118:092034+504148. Based on that information it was confirmed as an exploding star in January 2015. It was thought then that it was a single supernova event (Type II supernova, Type II-P) that would dim in about 100 days, but instead, it continued its eruption for about 1,000 days while fluctuating in brightness at least five times. The brightness varied by as much as 50%, going through five peaks. Also, rather than cooling down with time as expected of a Type II super ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IPTF14hls
iPTF14hls is an unusual supernova star that erupted continuously for about 1,000 days beginning in September 2014 before becoming a Supernova remnant, remnant nebula. It had previously erupted in 1954. None of the theories nor proposed hypotheses fully explain all the aspects of the object. Observations The star iPTF14hls was discovered in September 2014 by the Intermediate Palomar Transient Factory, and it was first made public in November 2014 by the Catalina Real-time Transient Survey, CRTS survey as CSS141118:092034+504148. Based on that information it was confirmed as an exploding star in January 2015. It was thought then that it was a single supernova event (Type II supernova, Type II-P) that would dim in about 100 days, but instead, it continued its eruption for about 1,000 days while fluctuating in brightness at least five times. The brightness varied by as much as 50%, going through five peaks. Also, rather than cooling down with time as expected of a Type II super ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulsational Pair-instability Supernova
A pulsational pair-instability supernova is a supernova impostor event that generally occurs in stars at around 100 to 130 solar mass (), as opposed to a typical pair-instability supernova which occurs in stars of 130 to . Like pair-instability supernovae, pulsational pair-instability supernovae are caused by draining of a star's energy in the production of electron-positron pairs but, whereas a pair-instability supernova completely disrupts the star in a massive supernova, the star's pulsational pair-instability eruption sheds . This generally shrinks it down to a mass of less than , too small for electron-positron pair creation, where it then undergoes a Core-collapse supernova, core-collapse supernova or hypernova. It is possible that this is what occurred during the 1843 eruption of the primary star of the Eta Carinae star system although there is no substantial evidence supporting this. Stellar behaviours Below Thermal Gamma radiation, gamma rays in the cores of stars of les ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Hole
A black hole is a region of spacetime where gravitation, gravity is so strong that nothing, including light or other Electromagnetic radiation, electromagnetic waves, has enough energy to escape it. The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole. The boundary (topology), boundary of no escape is called the event horizon. Although it has a great effect on the fate and circumstances of an object crossing it, it has no locally detectable features according to general relativity. In many ways, a black hole acts like an ideal black body, as it reflects no light. Moreover, quantum field theory in curved spacetime predicts that event horizons emit Hawking radiation, with thermal radiation, the same spectrum as a black body of a temperature inversely proportional to its mass. This temperature is of the order of billionths of a kelvin for stellar black holes, making it essentially impossible to observe directly. Obje ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SN 2009ip
SN 2009ip was a supernova discovered in 2009 in the spiral galaxy NGC 7259 in the constellation of Piscis Austrinus. Since the brightness waned after days post-discovery, it was redesignated as Luminous blue variable (LBV) Supernova impostor. During the following years several luminous outbursts were detected from the SN 2009ip. In September 2012 SN 2009ip was classified as a young type IIn supernova A Type II supernova (plural: ''supernovae'' or ''supernovas'') results from the rapid collapse and violent explosion of a massive star. A star must have at least 8 times, but no more than 40 to 50 times, the mass of the Sun () to undergo th .... References Further reading * * * * * * * * * * * * * * * * * * External links Light curves and spectraon thOpen Supernova CatalogRochester Academy of Science Supernovae Astronomical objects discovered in 2009 Piscis Austrinus Luminous blue variables {{var-star-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SN 1998S
SN 1998S was a type IIn supernova that was detected in NGC 3877 in March 1998. At the time of discovery, SN 1998S was the brightest type IIn event observed, although later outshone by SN 2010jl. It was discovered on 1998 March 2.68 UT in NGC 3877 NGC 3877 is a type Sc spiral galaxy that was discovered by William Herschel on February 5, 1788. It is located below the magnitude 3.7 star Chi Ursae Majoris in Ursa Major. Supernova The Type IIn supernova SN 1998S is the only supernova th ... by Z. Wan at a broadband (unfiltered) optical magnitude of +15.2. Its spectrum showed prominent H and He emission lines with narrow peaks and broad wings, superimposed on a blue continuum. These narrow lines indicate the presence of a dense circumstellar medium (CSM) in the vicinity of the supernova. The high luminosity of SN1998S is due to the interaction of fast material (ejecta) with previously-expelled slowly-expanding material (CSM), which can more effectively convert kinetic energ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nathan Smith (astronomer)
Nathan Smith may refer to: Sports *Nathan Smith (Irish cricketer) (born 1995), Irish cricketer * Nathan Smith (New Zealand cricketer) (born 1998), New Zealand cricketer * Nathan Smith (rugby league, born 1983), Australian rugby league player for Penrith Panthers *Nathan Smith (rugby league, born 1988), Australian rugby league footballer for the Parramatta Eels *Nathan Smith (footballer, born 1987), English-born Jamaican football player *Nathan Smith (soccer, born 1994), American soccer player *Nathan Smith (footballer, born 1996), English football player * Nathan Smith (golfer) (born 1978), American amateur golfer *Nate Smith (golfer) (born 1983), American professional golfer on the Nationwide Tour *Nathan Smith (ice hockey, born 1982), Canadian NHL player *Nathan Smith (ice hockey, born 1998), American Olympic hockey player *Nathan Smith (biathlete) (born 1985), Canadian biathlete Others *Nathan Smith (politician) (1770–1835), U.S. Senator * Nathan Lloyd Smith (1975–2002), Cana ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jennifer E Andrews (astronomer)
Jennifer or Jenifer may refer to: People *Jennifer (given name) * Jenifer (singer), French pop singer * Jennifer Warnes, American singer who formerly used the stage name Jennifer * Daniel of St. Thomas Jenifer * Daniel Jenifer Film and television * ''Jennifer'' (1953 film), a film starring Ida Lupino * ''Jennifer'' (1978 film), a horror film by Brice Mack * ''Jennifer'', a 1998 Ghanaian film starring Brew Riverson Jnr * "Jenifer" (''Masters of Horror''), an episode of ''Masters of Horror'' Music * The Jennifers, a British band, some of whose members later formed Supergrass * ''Jenifer'' (album), an album by French singer Jenifer * ''Jennifer'' (album), a 1972 album by Jennifer Warnes * "Jennifer", a 1974 song by Faust from ''Faust IV'' * "Jennifer", a 1983 song by Eurythmics from ''Sweet Dreams (Are Made of This)'' (album) * "Jennifer", a 2001 song by M2M from ''The Big Room'' Other uses * Hurricane Jennifer * Project Jennifer, a CIA attempt to recover a Soviet su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetar
A magnetar is a type of neutron star with an extremely powerful magnetic field (∼109 to 1011 T, ∼1013 to 1015 G). The magnetic-field decay powers the emission of high-energy electromagnetic radiation, particularly X-rays and gamma rays.Ward; Brownlee, p.286 The existence of magnetars was proposed in 1992 by Robert Duncan and . Their proposal sought to explain the properties of transient sources of gamma rays, now known as soft gamma repeaters (SGRs). Over the following decade, the magnetar hypothesis became widely accepted, and was extended to explain anomalous X-ray pulsars (AXPs). , 24 confirmed magnetars were known. It has been suggested that magnetars are the source of fast radio bursts (FRB), in particular as a result of findings in 2020 by scientists using the Australian Square Kilometre Array. Description Like other neutron stars, magnetars are around in diameter, and have a mass about 1.4 solar masses. They are formed by the collapse of a star with a mass 10– ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supernova Impostor
Supernova impostors are stellar explosions that appear at first to be a supernova but do not destroy their progenitor stars. As such, they are a class of extra-powerful novae. They are also known as Type V supernovae, Eta Carinae analogs, and giant eruptions of luminous blue variables (LBV). Appearance, origin and mass loss Supernova impostors appear as remarkably faint supernovae of spectral type IIn—which have hydrogen in their spectrum and narrow spectral lines that indicate relatively low gas speeds. These impostors exceed their pre-outburst states by several magnitudes, with typical peak absolute visual magnitudes of −11 to −14, making these outbursts as bright as the most luminous stars. The trigger mechanism of these outbursts remains unexplained, though it is thought to be caused by violating the classical Eddington luminosity limit, initiating severe mass loss. If the ratio of radiated energy to kinetic energy is near unity, as in Eta Carinae, then we might expect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antimatter
In modern physics, antimatter is defined as matter composed of the antiparticles (or "partners") of the corresponding particles in "ordinary" matter. Antimatter occurs in natural processes like cosmic ray collisions and some types of radioactive decay, but only a tiny fraction of these have successfully been bound together in experiments to form antiatoms. Minuscule numbers of antiparticles can be generated at particle accelerators; however, total artificial production has been only a few nanograms. No macroscopic amount of antimatter has ever been assembled due to the extreme cost and difficulty of production and handling. Theoretically, a particle and its antiparticle (for example, a proton and an antiproton) have the same mass, but opposite electric charge, and other differences in quantum numbers. A collision between any particle and its anti-particle partner leads to their mutual annihilation, giving rise to various proportions of intense photons (gamma rays), neutrin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photosphere
The photosphere is a star's outer shell from which light is radiated. The term itself is derived from Ancient Greek roots, φῶς, φωτός/''phos, photos'' meaning "light" and σφαῖρα/''sphaira'' meaning "sphere", in reference to it being a spherical surface that is perceived to emit light. It extends into a star's surface until the plasma becomes opaque, equivalent to an optical depth of approximately , or equivalently, a depth from which 50% of light will escape without being scattered. A photosphere is the deepest region of a luminous object, usually a star, that is transparent to photons of certain wavelengths. Temperature The surface of a star is defined to have a temperature given by the effective temperature in the Stefan–Boltzmann law. Stars, except neutron stars, have no solid or liquid surface. Therefore, the photosphere is typically used to describe the Sun's or another star's visual surface. Composition of the Sun The Sun is composed primarily of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circumstellar Envelope
A circumstellar envelope (CSE) is a part of a star that has a roughly spherical shape and is not gravitationally bound to the star core. Usually circumstellar envelopes are formed from the dense stellar wind, or they are present before the formation of the star. Circumstellar envelopes of old stars (Mira variables and OH/IR stars) eventually evolve into protoplanetary nebulae, and circumstellar envelopes of young stellar objects evolve into circumstellar discs. Types of circumstellar envelopes * Circumstellar envelopes of AGB stars * Circumstellar envelopes around young stellar objects See also * Circumstellar dust * Common envelopes * Stellar evolution Stellar evolution is the process by which a star changes over the course of time. Depending on the mass of the star, its lifetime can range from a few million years for the most massive to trillions of years for the least massive, which is cons ... References External links The Structure and Evolution of Envelopes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
