PSR J2144-3933
Encyclopedia
|- style="vertical-align: top;"
| Distance
| 587.088 Ly (180 parsec
s)
PSR J2144-3933 is a pulsar
about 180 parsec
s (5.5 Em) from Earth. It was previously thought to have a period of 2.84 second
s but is now known to have a period of 8.51 s, which is among the longest known radio pulsar.
J2144-3933 is notable for other reasons: its mean pulse profile is very narrow in comparison to the pulse period with a half-intensity width of less than one degree of longitude. It also has the lowest spindown luminosity of any pulsar at about 3×1021 watt
s.
Writing in Nature
, astrophysicists M. D. Young and coworkers consider this object and suggest that its existence throws current theories into doubt. They state:
| Distance
Cosmic distance ladder
The cosmic distance ladder is the succession of methods by which astronomers determine the distances to celestial objects. A real direct distance measurement of an astronomical object is possible only for those objects that are "close enough" to Earth...
| 587.088 Ly (180 parsec
Parsec
The parsec is a unit of length used in astronomy. It is about 3.26 light-years, or just under 31 trillion kilometres ....
s)
PSR J2144-3933 is a pulsar
Pulsar
A pulsar is a highly magnetized, rotating neutron star that emits a beam of electromagnetic radiation. The radiation can only be observed when the beam of emission is pointing towards the Earth. This is called the lighthouse effect and gives rise to the pulsed nature that gives pulsars their name...
about 180 parsec
Parsec
The parsec is a unit of length used in astronomy. It is about 3.26 light-years, or just under 31 trillion kilometres ....
s (5.5 Em) from Earth. It was previously thought to have a period of 2.84 second
Second
The second is a unit of measurement of time, and is the International System of Units base unit of time. It may be measured using a clock....
s but is now known to have a period of 8.51 s, which is among the longest known radio pulsar.
J2144-3933 is notable for other reasons: its mean pulse profile is very narrow in comparison to the pulse period with a half-intensity width of less than one degree of longitude. It also has the lowest spindown luminosity of any pulsar at about 3×1021 watt
Watt
The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...
s.
Writing in Nature
Nature (journal)
Nature, first published on 4 November 1869, is ranked the world's most cited interdisciplinary scientific journal by the Science Edition of the 2010 Journal Citation Reports...
, astrophysicists M. D. Young and coworkers consider this object and suggest that its existence throws current theories into doubt. They state:
- Moreover, under the usual model assumptions, based on the neutron-star equations of stateEquation of stateIn physics and thermodynamics, an equation of state is a relation between state variables. More specifically, an equation of state is a thermodynamic equation describing the state of matter under a given set of physical conditions...
, this slowly rotating pulsar should not be emitting a radio beam. Therefore either the model assumptions are wrong, or current theories of radio emission must be revised —from Nature 400, 848–849 (26 August 1999); doi:10.1038/23650)