FP trendFeb 03, 2021 12:07:09 PM IS
Astronomers have seen bizarre behavior from a magnetar, a type of neutron star that is believed to be one of the most powerful magnets in the universe. The latest discoveries shed light on their magnetic properties and therefore help scientists better understand their origins. A team from the ARC Center of Excellence for Gravitational Wave Discovery (OzGrav) and CSIRO carried out the observation. The study was published in the Royal Astronomical Society’s Monthly Notices on Monday, February 1.
Artist’s impression of the active magnetar Swift J1818.0-1607. Photo credit: Carl Knox, OzGrav.
A magnetized neutron star or magnetars are a very rare cosmic body with complex and strong magnetic fields. To date, astronomers have only discovered about 30 magnetars in and around the Milky Way. Some of them can emit radio waves, which is characteristic of a pulsar.
A pulsar, the less magnetic relatives of magnetars, which generate rays of radio waves from their magnetic poles.
One such magnetar that emits radio pulses, Swift J1818.0-1607 or J1818, was discovered in March 2020. Scientists discovered that it is a radioactive magnetar, that is, a star that can generate radio pulses. The “appearance” of the radio pulses recorded by J1818 was, however, “very different” than those which were recorded by other such magnetars in the past, see a Explanation from the ARC competence center for the discovery of gravitational waves.
While radio pulses from magnetars normally maintain a “constant brightness over a wide range of observation frequencies”, the pulses detected by J1818 were “much brighter at low frequencies than at high frequencies”. Scientists quickly noticed that this property was also observed in pulsars. Then the team observed the neutron star in 2020 for a period of five months.
Interestingly, J1818 was emitting unusual pulsar-like radio waves in May, but by June it began to flicker between magnetar and pulsar-like properties. This flicker peaked in July before turning to its magnetar-like state thereafter.
Swinburne University / CSIRO lead author and PhD student Marcus Lower said they found that “J1818’s magnetic axis is not aligned with its axis of rotation,” making it the first magnetar to have an “misaligned magnetic pole.”
Recently, the Chandra X-ray Observatory took a picture of a Supernova – RCW 103 – whose center (1E 1613) consists of a neutron star, but recently discovered that it is actually a magnetar.
