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PSR J0901–4046
PSR J0901–4046 is an ultra-long period pulsar. Its period, 75.9 seconds, is the longest for any known neutron star pulsar (some objects believed to be white dwarf pulsars, such as AR Scorpii, have longer periods). Its period is more than three times longer than that of PSR J0250+5854, the previous long period record-holder. The pulses are narrow; radio emission is seen from PSR J0901–4046 for only 0.5% of its rotation period. PSR J0901–4046 was discovered serendipitously on September 27, 2020, by the MeerTRAP team, when a single pulse from it was noticed during MeerKAT observations of Vela X-1 (which is less than 1/4 degree away from PSR J0901–4046 on the sky). After that pulse was detected, further examination of the data revealed that 14 weaker pulses were present in the ~30 minute long data set, but they had been missed by the real-time detection software. The deepest image of the MeerKAT field showed a diffuse shell-like structure that may be a supernova remna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vela (constellation)
Vela is a constellation in the southern sky, which contains the Vela Supercluster. Its name is Latin for the sails of a ship, and it was originally part of a larger constellation, the ship ''Argo Navis'', which was later divided into three parts, the others being Carina (constellation), Carina and Puppis. With an apparent magnitude of 1.8, its brightest star is the hot blue multiple star Gamma Velorum, one component of which is the brightest Wolf–Rayet star, Wolf-Rayet star in the sky. Delta Velorum, Delta and Kappa Velorum, together with Epsilon Carinae, Epsilon and Iota Carinae, form the asterism (astronomy), asterism known as the False Cross. 1.95-magnitude Delta is actually a triple or quintuple star system. History Argo Navis was one of the 48 classical constellations listed by the 2nd-century astronomer Ptolemy, and represented the ship ''Argo'', used by Jason and the Argonauts on their quest for the Golden Fleece in Greek mythology. German cartographer Johann Bayer depic ... [...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] |
Second
The second (symbol: s) is the unit of time in the International System of Units (SI), historically defined as of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds each (24 × 60 × 60 = 86400). The current and formal definition in the International System of Units ( SI) is more precise:The second ..is defined by taking the fixed numerical value of the caesium frequency, Δ''ν''Cs, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be when expressed in the unit Hz, which is equal to s−1. This current definition was adopted in 1967 when it became feasible to define the second based on fundamental properties of nature with caesium clocks. Because the speed of Earth's rotation varies and is slowing ever so slightly, a leap second is added at irregular intervals to civil time to keep clocks in sync with Earth's rotation. Uses Analog clocks and watches often ... [...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] |
AR Scorpii
AR Scorpii (AR Sco) is a binary pulsar that consists of a white dwarf and a red dwarf. It is located close to the ecliptic plane in the constellation Scorpius. Parallax measurements made by ''Gaia'' put the system at a distance of about 380 light-years (120 parsecs). AR Scorpii is the first, and as of 2021, the only "white dwarf-pulsar" to be discovered. Its unusual nature was first noticed by amateur astronomers. The 3.56-hour period in AR Scorpii's light curve caused it to be misclassified as a Delta Scuti variable, but in 2016, this period was found to be the binary orbital period. In addition, the system shows very strong optical, ultraviolet, and radio pulsations originating from the red dwarf with a period of just 1.97 minutes, which is a beat period from the orbital rotation and the white dwarf spin. These pulsations occur when a relativistic beam from the white dwarf sweeps across the red dwarf, which then reprocesses the beam into the observed electromagnetic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MeerKAT
MeerKAT, originally the Karoo Array Telescope, is a radio telescope consisting of 64 antennas in the Meerkat National Park, in the Northern Cape of South Africa. In 2003, South Africa submitted an expression of interest to host the Square Kilometre Array (SKA) Radio Telescope in Africa, and the locally designed and built MeerKAT was incorporated into the first phase of the SKA. MeerKAT was launched in 2018. Along with the Hydrogen Epoch of Reionization Array (HERA), also in South Africa, and two radio telescopes in Western Australia, the Australian SKA Pathfinder (ASKAP) and the Murchison Widefield Array (MWA), the MeerKAT is one of four precursors to the final SKA. History MeerKAT is a precursor for the SKA-mid array, as are the Hydrogen Epoch of Reionization Array (HERA), the Australian SKA Pathfinder (ASKAP) and the Murchison Widefield Array (MWA). Description It is located on the SKA site in the Karoo, and is a pathfinder for SKA-mid technologies and science. It was design ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vela X-1
Vela or Velas may refer to: Astronomy * Vela (constellation), a constellation in the southern sky (the Sails) ** Vela (Chinese astronomy) ** Vela Pulsar ** Vela X-1, a pulsing, eclipsing high-mass X-ray binary system Places * Vela Bluff, Antarctica *Vela, Dolj, Romania * Vela (Ilidža – Sarajevo), Bosnia and Herzegovina * Velas, Maharashtra, India Ships * '' CMA CGM Vela'', a container ship in service since 2008 * USNS ''Vela'' (T-AK-89), US Army port repair ship * ''Vela''-class submarine, of the Indian Navy ** INS ''Vela'' (S40), in service 1973–2010 Technology * Project Vela, a system developed by the United States to monitor compliance with the Partial Test Ban Treaty ** Vela (satellite), a series of satellites launched by the United States to monitor nuclear testing *** Vela Incident, an international incident, in which a Vela satellite is thought to possibly have observed a nuclear test * Versatile Laboratory Aid (VELA), a data logging tool used in education Peo ... [...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] |
GPM J1839−10
GPM J1839−10 is a potentially unique ultra-long period magnetar located about 15,000 light-years away from Earth in the Scutum constellation, in the Milky Way. It was discovered by a team of scientists at Curtin University using the Murchison Widefield Array. Its unusual characteristics violate current theory and prompted a search of other radio telescope archives, including the Giant Metrewave Radio Telescope and the Very Large Array, which revealed evidence of the object dating back to 1988. The signature of the object went unnoticed because scientists did not know to look for its unusual behavior. The current understanding of neutron stars is that below a certain rate of rotation, called "the death line", they cease emissions. Uniquely, not only does GPM J1839−10 have an extremely slow rotation of approximately twenty-two minutes, it emits bursts of radio waves lasting up to five minutes, for which there is currently no generally accepted explanation. See also * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PSR J1748−2446ad
, - ! style="background-color: #FFFFC0;" colspan="2" , Astrometry , - style="vertical-align: top;" , Distance , 18,000 Ly PSR J1748−2446ad is the fastest-spinning pulsar known, at 716 Hz (times per second), or 43,000 revolutions per minute. This pulsar was discovered by Jason W. T. Hessels of McGill University on November 10, 2004 and confirmed on January 8, 2005. If the neutron star is assumed to contain less than two times the mass of the Sun, within the typical range of neutron stars, its radius is constrained to be less than 16 km. At its equator it is spinning at approximately 24% of the speed of light, or over 70,000 km per second. The pulsar is located in a globular cluster of stars called Terzan 5, located approximately 18,000 light-years from Earth in the constellation Sagittarius. It is part of a binary system and undergoes regular eclipses with an eclipse magnitude of about 40%. Its orbit is highly circular, with a 26-hour period. The other ob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Objects Discovered In 2020
Astronomy () is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, galaxies, and comets. Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation. More generally, astronomy studies everything that originates beyond Earth's atmosphere. Cosmology is a branch of astronomy that studies the universe as a whole. Astronomy is one of the oldest natural sciences. The early civilizations in recorded history made methodical observations of the night sky. These include the Babylonians, Greeks, Indians, Egyptians, Chinese, Maya, and many ancient indigenous peoples of the Americas. In the past, astronomy included disciplines as diverse as astrometry, celestial navigation, observational astronomy, and the making of calendars. Nowadays, professi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
