A millisecond pulsar (MSP), often referred to as "recycled pulsar", is a pulsar with a rotational period in the range of about 1-10 milliseconds. It may be visible in the microwave or X-ray portions of the electromagnetic spectrum. It has been suggested that Radio pulsar be merged into this article or section. ... One millisecond is one-thousandth of a second. ... Composite Optical/X-ray image of the Crab Nebula pulsar, showing surrounding nebular gases stirred by the pulsars magnetic field and radiation. ... An X-ray pulsar is a neutron star with a powerful magnetic field that gives rise to regular X-ray pulses. ... Legend γ = Gamma rays HX = Hard X-rays SX = Soft X-Rays EUV = Extreme ultraviolet NUV = Near ultraviolet Visible light NIR = Near infrared MIR = Moderate infrared FIR = Far infrared Radio waves EHF = Extremely high frequency (Microwaves) SHF = Super high frequency (Microwaves) UHF = Ultra high frequency VHF = Very high frequency HF = High...

The origin of millisecond pulsars is still somewhat mysterious. The leading theory is that they begin life as longer period pulsars but are spun up or "recycled" through accretion. Because of this theory, systems known as low-mass X-ray binary systems have received a great deal of attention. It is thought that the X-rays in these system are emitted by the accretion disk of a neutron star produced by the outer layers of a companion star that has overflowed its Roche lobe. The transfer of angular momentum from this accretion event can theoretically increase the rotation rate of the pulsar to hundreds of times a second, as is observed in millisecond pulsars. See also: Accretion (finance) Accretion is increase in size by gradual addition of smaller parts. ... Low-mass X-ray binaries (LMXBs) are binary stars where one of the components is either a black hole or neutron star. ... An accretion disc (or accretion disk) is a structure formed by material falling into a gravitational source. ... For the Hugo Award-winning story by Larry Niven, see Neutron Star (story). ... A three-dimensional representation of the Roche potential in a binary star with a mass ratio of 2, in the co-rotating frame. ... This gyroscope remains upright while spinning due to its angular momentum. ...

Many millisecond pulsars are found in globular clusters. This is consistent with the spin-up theory of their formation, as the extremely high stellar density of these clusters implies a much higher likelihood of a pulsar having (or capturing) a giant companion star. Currently there are approximately 130 millisecond pulsars known in globular clusters [1]. The globular cluster Terzan 5 alone contains 33 of these, followed by 47 Tucanae with 22 and M28 and M15 with 8 pulsars each. The Globular Cluster M80 in the constellation Scorpius is located about 28,000 light years from the Sun and contains hundreds of thousands of stars. ... 47 Tucanae ( NGC 104) or just 47 Tuc is a globular cluster located in the constellation Tucana. ... The central square arcminute of M15 imaged using the lucky imaging technique Globular Cluster M15 (also known as Messier Object 15 or NGC 7078) is a globular cluster in the constellation Pegasus. ...

Pulsar rotational speed limits

The first millisecond pulsar, PSR B1937+21, was discovered in 1982 by Backer et al. Spinning roughly 641 times a second, it remains one of the swiftest-spinning neutron stars of the approximately 180 that have been discovered. Pulsar PSR J1748-2446ad, discovered in 2005, is, as of 2007, the swiftest spinning neutron star currently known, spinning 716 times a second [2], [3]. In astronomy, and in particular the study of pulsars, PSR J1748-2446ad is the fastest known spinning pulsar, at 716 Hz, the period being 0. ...

Current theories of neutron star structure and evolution predict that pulsars would break apart if they spun at a rate of 1500 rotations per second or more, and that at a rate of above about 1000 rotations per second they would lose energy by gravitational radiation faster than the accretion process would speed them up. To meet Wikipedias quality standards, this article or section may require cleanup. ...

However, in early 2007 data from the Rossi X-ray Timing Explorer and INTEGRAL spacecraft indicated that the neutron star XTE J1739-285 rotates at 1122 Hz.^[1]. However, this result is not statistically significant, with a significance level of only 3 sigma. Therefore, while it is an interesting candidate for further observations, current results are only suggestive. Still, it is believed that gravitational radiation plays a role in slowing the rate of rotation. Furthermore, one X-ray pulsar that spins at 599 revolutions per second, IGR J00291+5934, is a prime candidate for helping detect such waves in the future (most such X-ray pulsars only spin at around 300 rotations per second). Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... The Rossi X-ray Timing Explorer (RXTE) satellite observes the fast-moving, high-energy worlds of black holes, neutron stars, X-ray pulsars and bursts of X-rays that light up the sky and then disappear forever. ... This article is about the concept of integrals in calculus. ... An X-ray pulsar is a neutron star with a powerful magnetic field that gives rise to regular X-ray pulses. ...

References

1. ^ Spaceflight Now Accessed 20 Feb 2007

• "How Millisecond Pulsars Spin So Fast". Universe Today.
• "Fast-Spinning Star Could Test Gravitational Waves". New Scientist.