The object is one of the youngest of its kind that we know about

A GAMMA-RAY pulsar has been detected outside the Milky Way, the first time such an object has been seen in another galaxy. It has set a new record for the most luminous known gamma-ray pulsar.

The pulsar was seen in the Tarantula Nebula, located in the Large Magellanic Cloud. NASA’s Fermi Space Telescope identified the region as a bright source of gamma rays early into its mission, but initially the glow was attributed to supernovae. “It’s now clear that a single pulsar, PSR J0540-6919, is responsible for roughly half of the gamma-ray brightness we originally thought came from the nebula,” says Pierrick Martin, an astrophysicist at the National Center for Scientific Research and the Research Institute in Astrophysics and Planetology in Toulouse, France. “That is a genuine surprise.”

A pulsar is formed when a massive star goes supernova, leaving behind a highly magnetised ball spinning tens of times each second and throwing out enormous levels of radiation. PSR J0540-6919 is relatively young, at only 1,700 years old, and is one of around 160 gamma-ray pulsars currently known.

“The gamma-ray pulses from J0540 have 20 times the intensity of the previous recordholder, the pulsar in the famous Crab Nebula, yet they have roughly similar levels of radio, optical and X-ray emission,” says Lucas Guillemot from the Laboratory for Physics and Chemistry of Environment and Space. “Accounting for these differences will guide us to a better understanding of the extreme physics at work in young pulsars.”

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