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An X-ray pulsar is a type of binary star system consisting of a typical star (stellar companion) in orbit around a magnetized neutron star.The magnetic field strength at the surface of the neutron star is typically about 10 8 Tesla, over a trillion times stronger than the strength of the magnetic field measured at the surface of the Earth (60 μT).
Pulsars that were discovered before 1993 tend to retain their B names rather than use their J names (e.g. PSR J1921+2153 is more commonly known as PSR B1919+21). Recently discovered pulsars only have a J name (e.g. PSR J0437−4715). All pulsars have a J name that provides more precise coordinates of its location in the sky. [38]
An intermediate-mass binary pulsar (IMBP) is a pulsar-white dwarf binary system with a relatively long spin period of around 10–200 ms consisting of a white dwarf with a relatively high mass of approximately . [7] The spin periods, magnetic field strengths, and orbital eccentricities of IMBPs are significantly larger than those of low mass binary pulsars (LMBPs). [7]
Millisecond pulsars have been detected in radio, X-ray, and gamma ray portions of the electromagnetic spectrum. The leading hypothesis for the origin of millisecond pulsars is that they are old, rapidly rotating neutron stars that have been spun up or "recycled" through accretion of matter from a companion star in a close binary system.
Most observed magnetars rotate once every two to ten seconds, [8] whereas typical neutron stars, observed as radio pulsars, rotate one to ten times per second. [9] A magnetar's magnetic field gives rise to very strong and characteristic bursts of X-rays and gamma rays. The active life of a magnetar is short compared to other celestial bodies.
Dame Susan Jocelyn Bell Burnell (/ b ɜːr ˈ n ɛ l /; née Bell; born 15 July 1943) is an astrophysicist from Northern Ireland who, as a postgraduate student, discovered the first radio pulsars in 1967.
The pulsar provides a strong periodic signal that is used to check the timing of the X-ray detectors. In X-ray astronomy, "crab" and "millicrab" are sometimes used as units of flux density. A millicrab corresponds to a flux density of about 2.4 × 10 −11 erg s −1 cm −2 ( 2.4 × 10 −14 W/m 2 ) in the 2–10 keV X-ray band, for a "crab ...
The formation scenarios have consequences for the planets' composition: A planet formed from supernova debris is likely rich in metals and radioactive isotopes [15] and may contain large quantities of water; [18] one formed through the break-up of a white dwarf would be carbon rich [15] and consist of large amounts of diamond; [19] an actual white dwarf fragment would be extremely dense. [15]