The Vela Pulsar (PSR J0835-4510 or PSR B0833-45) is a radio, optical,

X-ray An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...

- and

gamma Gamma (; uppercase , lowercase ; ) is the third letter of the Greek alphabet. In the system of Greek numerals it has a value of 3. In Ancient Greek, the letter gamma represented a voiced velar stop . In Modern Greek, this letter normally repr ...

-emitting

pulsar A pulsar (''pulsating star, on the model of quasar'') is a highly magnetized rotating neutron star that emits beams of electromagnetic radiation out of its Poles of astronomical bodies#Magnetic poles, magnetic poles. This radiation can be obse ...

associated with the

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 years ago (and was about 900 light-years away). The association of the Vela supernova remn ...

in the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The first constellati ...

of Vela. Its parent

Type II supernova A Type II supernova or SNII (plural: ''supernovae'') results from the rapid collapse and violent explosion of a massive star. A star must have at least eight times, but no more than 40 to 50 times, the mass of the Sun () to undergo this type ...

exploded approximately 11,000–12,300 years ago (and was about 800

light-year A light-year, alternatively spelled light year (ly or lyr), is a unit of length used to express astronomical distances and is equal to exactly , which is approximately 9.46 trillion km or 5.88 trillion mi. As defined by the International Astr ...

s away).

Characteristics

Vela is the brightest pulsar (at radio frequencies) in the sky and spins 11 times per second (i.e. a period of 89.33 milliseconds—the shortest known at the time of its discovery) and the remnant from the supernova explosion is estimated to be travelling outwards at . It has the third-brightest optical component of all known pulsars (V = 23.6 mag) which pulses twice for every single radio pulse. The Vela pulsar is the brightest persistent object in the high-energy gamma-ray sky. Pulsed emission up to 20

TeV TEV may refer to: * Transient Earth voltage: a term for voltages appearing on the metal work of switchgear due to internal partial discharges * TeV, or teraelectronvolt or trillion electron volt, a measure of energy * Total enterprise value, a ...

has been detected from the Vela pulsar and together with the

Crab pulsar The Crab Pulsar (PSR B0531+21 or Baade's Star) is a relatively young neutron star. The star is the central star in the Crab Nebula, a remnant of the supernova SN 1054, which was widely observed on Earth in the year 1054.

at 1.5 TeV these are the only two known pulsars with emission in this energy range.

Glitches

Glitches A glitch is a short-lived technical fault, such as a transient one that corrects itself, making it difficult to troubleshoot. The term is particularly common in the computing and electronics industries, in circuit bending, as well as among pla ...

are sudden spin-ups in the rotation of pulsars. Vela is the best known of all the glitching pulsars, with glitches occurring on average every three years. Glitches are currently not predictable. On 12 December 2016, Vela was observed to glitch live for the first time with a radio telescope (the 26 m telescope at the

Mount Pleasant Radio Observatory The Mount Pleasant Radio Observatory is a radio astronomy, radio-astronomy-based observatory owned and operated by the University of Tasmania, located 20 km east of Hobart in Cambridge, Tasmania. It is home to three radio astronomy antennas ...

) large enough to see individual pulses. This observation showed that the pulsar nulled (i.e. did not pulse) for one pulse, with the pulse prior being very broad and the two following pulses featuring low

linear polarization In electrodynamics, linear polarization or plane polarization of electromagnetic radiation is a confinement of the electric field vector or magnetic field vector to a given plane along the direction of propagation. The term ''linear polarizati ...

. It also appeared that the glitch process took under five seconds to occur and allowed to estimate physical properties of the pulsar. On 22 July 2021, a new glitch occurred. As a result, the period of the pulsar decreased by about 1 part in a million. Statistically, nearly the 1% of the long-term spin-down of the pulsar is reversed in spin-up glitches, a fraction that is also observed in other monitored pulsars. Careful estimation of the glitch activity and its uncertainty requires statistical tools beyond the simple linear regression.

Research campaigns

The association of the Vela pulsar with the

, made by astronomers at the

University of Sydney The University of Sydney (USYD) is a public university, public research university in Sydney, Australia. Founded in 1850, it is the oldest university in both Australia and Oceania. One of Australia's six sandstone universities, it was one of the ...

in 1968, was direct observational proof that

supernova A supernova (: supernovae or supernovas) is a powerful and luminous explosion of a star. A supernova occurs during the last stellar evolution, evolutionary stages of a massive star, or when a white dwarf is triggered into runaway nuclear fusion ...

e form

neutron star A neutron star is the gravitationally collapsed Stellar core, core of a massive supergiant star. It results from the supernova explosion of a stellar evolution#Massive star, massive star—combined with gravitational collapse—that compresses ...

s. Studies conducted by Kellogg ''et al.'' with the ''Uhuru'' spacecraft in 1970–71 showed the Vela pulsar and Vela X to be separate but spatially related objects. The term ''Vela X'' was used to describe the entirety of the supernova remnant. Weiler and Panagia established in 1980 that Vela X was actually a

pulsar wind nebula A pulsar wind nebula (PWN, plural PWNe), sometimes called a plerion (derived from the Greek "πλήρης", ''pleres'', meaning "full"), is a type of nebula sometimes found inside the shell of a supernova remnant (SNR), powered by winds generate ...

, contained within the fainter supernova remnant and driven by energy released by the pulsar.

Nomenclature

The pulsar is occasionally referred to as ''Vela X'', but this phenomenon is separate from either the pulsar or the Vela X nebula. A radio survey of the Vela-Puppis region was made with the

Mills Cross Telescope The Mills Cross Telescope was a two-dimensional radio telescope built by Bernard Mills in 1954 at the Fleurs field station of the Australian Commonwealth Scientific and Industrial Research Organisation in the area known now as Badgerys Creek, a ...

in 1956–57 and identified three strong radio sources: Vela X, Vela Y, and Vela Z. These sources are observationally close to the

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 ye ...

supernova remnant, which is also a strong X-ray and radio source. Neither the pulsar nor either of the associated nebulae should be confused with

Vela X-1 Vela X-1 is a pulsing, eclipsing high-mass X-ray binary (HMXB) system, associated with the Uhuru source 4U 0900-40 and the supergiant star HD 77581. The X-ray emission of the neutron star is caused by the capture and accretion ...

, an observationally close but unrelated

high-mass X-ray binary X-ray binaries are a class of binary stars that are luminous in X-rays. The X-rays are produced by matter falling from one component, called the ''donor'' (usually a relatively common main sequence star), to the other component, called the ''acc ...

system.

In music

The emissions of Vela and the pulsar

PSR B0329+54 PSR B0329+54 is a pulsar approximately 5,300 light-years away in the constellation of Camelopardalis. It completes one rotation every 0.714 seconds and is approximately 5 million years old. The emissions of this pulsar and the Vela Pulsar ...

were converted into audible sound by French composer

Gérard Grisey Gérard Henri Grisey (; ; 17 June 1946 – 11 November 1998) was a twentieth-century French composer of contemporary classical music. His work is often associated with the Spectralist Movement in music, of which he was a major pioneer. Biograp ...

and used in the piece ''Le noir de l'étoile'' (1989–90).

Gallery

File:Cycle of pulsed gamma rays from the Vela pulsar 220px.gif , Cycle of pulsed

gamma ray A gamma ray, also known as gamma radiation (symbol ), is a penetrating form of electromagnetic radiation arising from high energy interactions like the radioactive decay of atomic nuclei or astronomical events like solar flares. It consists o ...

s from the Vela pulsar File:267641main allsky labeled HI.jpg , Position of the Vela Pulsar in the Milky Way File:Vela Pulsar jet seen by Chandra Observatory.ogv , Video consisting of eight images of Vela's particle jet, looped continuously

References

External links

Vela Pulsar
at

SIMBAD SIMBAD (the Set of Identifications, Measurements and Bibliography for Astronomical Data) is an astronomy, astronomical database of objects beyond the Solar System. It is maintained by the Centre de données astronomiques de Strasbourg (CDS), Fr ...

Vela Pulsar
at

NASA/IPAC Extragalactic Database The NASA/IPAC Extragalactic Database (NED) is an online astronomical database for astronomers that collates and cross-correlates astronomical information on extragalactic objects (galaxies, quasars, radio, x-ray and infrared sources, etc.). NED was ...

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