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Vela Supernova Remnant
__NOTOC__ The Vela supernova remnant is a supernova remnant in the southern constellation Vela. Its source Type II supernova exploded approximately 11,000–12,300 years ago (and was about 800 light-years away). The association of the Vela supernova remnant with the Vela pulsar, made by astronomers at the University of Sydney in 1968, was direct observational evidence that supernovae form neutron stars. The Vela supernova remnant includes NGC 2736. The Vela supernova remnant overlaps the Puppis A supernova remnant, which is four times more distant. Both the Puppis and Vela remnants are among the largest and brightest features in the X-ray sky. The Vela supernova remnant is one of the closest known to us. The Geminga pulsar is closer (and also resulted from a supernova), and in 1998 another near-Earth supernova remnant was discovered, RX J0852.0-4622, which from our point of view appears to be contained in the southeastern part of the Vela remnant. One estimate of its distanc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supernova Remnant
A supernova remnant (SNR) is the structure resulting from the explosion of a star in a supernova. The supernova remnant is bounded by an expanding shock wave, and consists of ejected material expanding from the explosion, and the interstellar material it sweeps up and shocks along the way. There are two common routes to a supernova: either a massive star may run out of fuel, ceasing to generate fusion energy in its core, and collapsing inward under the force of its own gravity to form a neutron star or a black hole; or a white dwarf star may accrete material from a companion star until it reaches a critical mass and undergoes a thermonuclear explosion. In either case, the resulting supernova explosion expels much or all of the stellar material with velocities as much as 10% the speed of light (or approximately 30,000 km/s). These speeds are highly supersonic, so a strong shock wave forms ahead of the ejecta. That heats the upstream plasma up to temperatures well above mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puppis A
Puppis A (Pup A) is a supernova remnant (SNR) about 100 light-years in diameter and roughly 6500–7000 light-years distant. Its apparent angular diameter is about 1 degree. The light of the supernova explosion reached Earth approximately 3700 years ago. Although it overlaps the Vela Supernova Remnant, it is four times more distant. A hypervelocity neutron star known as the Cosmic Cannonball has been found in this SNR. Puppis X-1 Puppis X-1 (Puppis A) was discovered by a Skylark flight in October 1971, viewed for 1 min with an accuracy ≥ 2 arcsec, probably at 1M 0821-426, with Puppis A ( RA 08h 23m 08.16s Dec -42° 41′ 41.40″) as the likely visual counterpart. Puppis A is one of the brightest X-ray sources in the X-ray sky. Its X-ray designation is 2U 0821-42. Gallery Image:PIA18468-SuperNova-PuppisA-XRayIR-20140821.jpg, Puppis A: X-ray lue:0.3-8 keV+ IR ed-green:24-70 microns(21 August 2014). Image:SuperNova-PuppisA-XRay-20140910.jpg, Puppis A: X-ray lue:high ree ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gum Nebula
The Gum Nebula (Gum 12) is an emission nebula that extends across 36° in the southern constellations Vela and Puppis. It lies approximately 450 parsecs from the Earth. Hard to distinguish, it was widely believed to be the greatly expanded (and still expanding) remains of a supernova that took place about a million years ago. More recent research suggests it may be an evolved H II region. It contains the 11,000-year-old Vela Supernova Remnant, along with the Vela Pulsar. The Gum Nebula contains about 32 cometary globules. These dense cloud cores are subject to such strong radiation from O-type stars γ2 Vel and ζ Pup and formerly the progenitor of the Vela Supernova Remnant that the cloud cores evaporate away from the hot stars into comet-like shapes. Like ordinary Bok globules, cometary globules are believed to be associated with star formation. It is named after its discoverer, the Australian astronomer Colin Stanley Gum (1924–1960). Gum had published his findings in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Supernovae
This is a list of supernovae that are of historical significance. These include supernovae that were observed prior to the availability of photography, and individual events that have been the subject of a scientific paper that contributed to supernova theory. An alternative, complete and updated list can be found in thOpen Supernova Catalog List ''In most entries, the year when the supernova was seen is part of the designation (1st column).'' See also * List of most distant supernovae * List of supernova candidates * List of supernova remnants * Lists of astronomical objects References Further reading * External linksList of all known supernovaeaThe Open Supernova CatalogIAU Supernovaeon thTransient Name Server (TNS) at IAU |
List Of Supernova Remnants
This is a list of observed supernova remnants (SNRs) in the Milky Way, as well as galaxies nearby enough to resolve individual nebulae, such as the Large Magellanic Cloud, Large and Small Magellanic Clouds and the Andromeda Galaxy. Supernova remnants typically only survive for a few tens of thousands of years, making all known SNRs fairly young compared to many other astronomical objects. See also *List of supernovae *Supernova *Lists of astronomical objects References External linksList of all known (extra)galactic supernova remnantsaThe Open Supernova Catalog {{DEFAULTSORT:List Of Supernova Remnants Lists of nebulae, Supernova Remnants Supernova remnants, * Light sources, Supernova Remnants, list of Articles containing video clips ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CG 4
CG 4, commonly referred to as God's Hand, is a star-forming region located in the Puppis constellation, about from Earth. It is one of several objects referred to as " cometary globules", because its shape is similar to that of a comet. It has a dense head formed of gas and dust, which is around in diameter, and an elongated faint tail around in length. , and the nearby cometary globules, generally point away from the Vela Supernova Remnant, located at the center of the Gum Nebula. Discovery In 1976, photographs from the UK Schmidt Telescope—operated by the Australian Astronomical Observatory—showed several objects resembling comets, located in the Gum Nebula, an emission nebula of the constellation. Due to their particular shape, these objects came to be known as cometary globules. Each globule has a dense, dark, ruptured head and a very long tail, with the latter pointing away from the Vela Supernova Remnant. As a part of the ESO Cosmic Gems program, the European Sout ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titanium-44
Naturally occurring titanium (22Ti) is composed of five stable isotopes; 46Ti, 47Ti, 48Ti, 49Ti and 50Ti with 48Ti being the most abundant (73.8% natural abundance). Twenty-one radioisotopes have been characterized, with the most stable being 44Ti with a half-life of 60 years, 45Ti with a half-life of 184.8 minutes, 51Ti with a half-life of 5.76 minutes, and 52Ti with a half-life of 1.7 minutes. All of the remaining radioactive isotopes have half-lives that are less than 33 seconds, and the majority of these have half-lives that are less than half a second. The isotopes of titanium range in atomic mass from 38.01 u (38Ti) to 62.99 u (63Ti). The primary decay mode for isotopes lighter than the stable isotopes (lighter than 46Ti) is β+ and the primary mode for the heavier ones (heavier than 50Ti) is β−; their respective decay products are scandium isotopes and the primary products after are vanadium isotopes. List of isotopes , - , rowspan=3, 39Ti , rowspan=3 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parsec
The parsec (symbol: pc) is a unit of length used to measure the large distances to astronomical objects outside the Solar System, approximately equal to or (au), i.e. . The parsec unit is obtained by the use of parallax and trigonometry, and is defined as the distance at which 1 au subtends an angle of one arcsecond ( of a degree). This corresponds to astronomical units, i.e. 1\, \mathrm = 1/\tan \left( \ \mathrm \right)\, \mathrm. The nearest star, Proxima Centauri, is about from the Sun. Most stars visible to the naked eye are within a few hundred parsecs of the Sun, with the most distant at a few thousand. The word ''parsec'' is a portmanteau of "parallax of one second" and was coined by the British astronomer Herbert Hall Turner in 1913 to make calculations of astronomical distances from only raw observational data easy for astronomers. Partly for this reason, it is the unit preferred in astronomy and astrophysics, though the light-year remains prominent in popular s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Near-Earth Supernova
A near-Earth supernova is an explosion resulting from the death of a star that occurs close enough to the Earth (roughly less than 10 to 300 parsecs (30 to 1000 light-years) away) to have noticeable effects on Earth's biosphere. An estimated 20 supernova explosions have happened within 300 pc of the Earth over the last 11 million years. Type II supernova explosions are expected to occur in active star-forming regions, with 12 such OB associations being located within 650 pc of the Earth. At present, there are six near-Earth supernova candidates within 300 pc. Effects on Earth On average, a supernova explosion occurs within of the Earth every 240 million years. Gamma rays are responsible for most of the adverse effects that a supernova can have on a living terrestrial planet. In Earth's case, gamma rays induce radiolysis of diatomic N2 and O2 in the upper atmosphere, converting molecular nitrogen and oxygen into nitrogen oxides, depleting the ozone layer enou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulsar
A pulsar (from ''pulsating radio source'') is a highly magnetized rotating neutron star that emits beams of electromagnetic radiation out of its magnetic poles. This radiation can be observed only when a beam of emission is pointing toward Earth (similar to the way a lighthouse can be seen only when the light is pointed in the direction of an observer), and is responsible for the pulsed appearance of emission. Neutron stars are very dense and have short, regular rotational periods. This produces a very precise interval between pulses that ranges from milliseconds to seconds for an individual pulsar. Pulsars are one of the candidates for the source of ultra-high-energy cosmic rays. (See also centrifugal mechanism of acceleration.) The periods of pulsars make them very useful tools for astronomers. Observations of a pulsar in a binary neutron star system were used to indirectly confirm the existence of gravitational radiation. The first extrasolar planets were discovered aroun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geminga
Geminga is a gamma ray and x-ray pulsar source thought to be a neutron star approximately 250 parsecs (around 800 light-years) from the Sun in the constellation Gemini. Its name, attributed by its discoverer Giovanni Bignami, is both a contraction of ''Gemini gamma-ray source'', and a transcription of the words ''ghè minga'' (), meaning "it's not there" in the Milanese dialect of Lombard. The name was approved by the International Astronomic Union on 4 April 2022. Pulsar The nature of Geminga was quite unknown for 20 years after its discovery by NASA's Second Small Astronomy Satellite (SAS-2). Finally, in March 1991 the ROSAT satellite detected a periodicity of 0.237 seconds in soft x-ray emission. Thus, it is supposed that Geminga is a sort of neutron star: the decaying core of a massive star that exploded as a supernova about 300,000 years ago. It was once thought that this nearby explosion was responsible for the low density of the interstella ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
