Editing PSR J0737−3039 (section)

== Pulsars ==
A pulsar is a [[neutron star]] which produces pulsating radio emission due to a strong [[magnetic field]].  A neutron star is the ultra-compact remnant of a massive star which exploded as a [[supernova]].  Neutron stars have a mass bigger than the [[Sun]], yet are only a few kilometers across. These extremely dense objects rotate on their [[Rotation around a fixed axis|axes]], producing focused [[electromagnetic waves]] which sweep around the sky and briefly point toward Earth in a lighthouse effect at rates that can reach a few hundred pulses per second.

Although double neutron star systems were known before its discovery, PSR J0737−3039 is the first and only known system ({{asof|2021|lc=y}}) where both neutron stars are pulsars&nbsp;– hence, a "double pulsar" system.<ref name="Silva2021"/>  The object is similar to [[PSR B1913+16]], which was discovered in 1974 by Jocelyn Bell, [[Joseph Hooton Taylor Jr.|Taylor]] and [[Russell Alan Hulse|Hulse]], and for which the two won the 1993 [[Nobel Prize in Physics]]. Objects of this kind enable precise testing of [[Albert Einstein|Einstein]]'s theory of [[general relativity]], because the precise and consistent timing of the pulsar pulses allows relativistic effects to be seen when they would otherwise be too small.  While many known pulsars have a binary companion, and many of those are believed to be neutron stars, J0737−3039 is the first case where both components are known to be not just neutron stars but pulsars.

===Discovery===
PSR J0737−3039A was discovered in 2003, along with its partner, at Australia's 64&nbsp;m antenna of the [[Parkes Observatory|Parkes Radio Observatory]];  J0737−3039B was not identified as a pulsar until a second observation. The system was originally observed by an international team during a high-latitude multibeam survey organized in order to discover more pulsars in the night sky.<ref name="firstdp" />

Initially, this [[star system]] was thought to be an ordinary pulsar detection. The first detection showed one pulsar with a period of 23 milliseconds in orbit around a neutron star. Only after follow up observations was a weaker second pulsar detected with a pulse of 2.8 seconds from the companion star.