Only 31 Magnetars Have Ever Been Discovered. This one is Extra Strange. It’s Also a Pulsar

Some of the most stunningly powerful objects in the sky aren’t necessarily the prettiest to look at.  But their secrets can allow humanity to glimpse some of the more intricate details of the universe that are exposed in their extreme environs.  Any time we find one of these unique objects it’s a cause for celebration, and recently astronomers have found an extremely unique object that is both a magnetar and a pulsar, making it one of only 5 ever found.

The object, called J1818.0-1607, was first detected in March by NASA’s Neil Gehreis Swift Telescope.  It was first classified simply as a magnetar – one of only 31 ever found.  Magnetars are a type of neutron star that has the strongest magnetic field ever detected – millions of billions of times stronger than that of Earth.  But J1818.0-1607 wasn’t the same as other magnetars found so far.

It appeared to be the youngest, with an estimated age of 500 years.  Correspondingly, it also spins faster than any other observed magnetar.  Younger magnetars will spin more quickly than older ones, which have had a chance to slow down some.  J1818.0-1607 takes the cake with a blistering rotational speed of 1.4 seconds.  

Finding a unique magnetar such as this will always attract other astronomers, and some brought other kinds of telescopes to bear.  One of those telescopes was the Chandra X-ray Observatory, which a team led by researchers from the University of West Virginia and the University of Manitoba commanded to look at the newly found magnetar less than a month after its original discovery.

Chandra is able to see in the X-ray spectrum, so it was able to calculate the efficiency with which the object was translating its decreasing spin energy into X-rays.  That efficiency was in line with another type of object, known as a rotation-powered pulsar.

Pulsars are a type of neutron star that repeatedly pulses out radiation as it spins.  Observations from other telescopes, including the Very Large Array, provided supporting data for the magnetar to also be a pulsar.  That puts it on a very short list of only 5 objects ever discovered that combined the characteristics of both types of object.

All of the mysteries of the newly discovered object are not yet solved, however.  One is where all the debris has gone.  All neutron stars are formed as a result of a supernova, and J1818.0-1607 is no exception. However, at such a young age, astronomers would expect to see the debris field from the explosion.  There was some that Chandra picked up, however, it is much farther away than expected, implying that J1818.0-1607 is either much older than previously thought, or that it exploded with such force that it blew the debris field out much faster than other known neutron stars.

Either hypothesis is viable, and of course more data will need to be collected in order to truly solve that mystery.  But the discovery of J1818.0-1607 and its subsequent observation are an excellent example of the kind of science that is possible when multiple instruments operating in multiple spectra are brought to bear on a single object of interest.  With luck that coordination will lead to more discoveries of these ultra rare combinations of magnetically powerful lighthouses.

Learn More:
NASA: Chandra Studies Extraordinary Magnetar
NASA: A Cosmic Baby is Discovered and Its Brilliant
Sci-News: Astronomers Discover Youngest Magnetar Ever
UT: A brand new magnetar found, it’s only 240 years old

Lead Image: Composite image of J1818.0-1607 in Xray and infrared.
Credit: NASA / CXC / U West Virginia / H. Blumer / JPL-CalTech / Spitzer