The Slowest spinning Pulsar - " Do Scientists really need to refresh their Death Line "

Pulsars are one of the most dense and the most strange objects present out there in the Cosmos. They are called as the Light-house of the Cosmos because they continuously emit a beam of electromagnetic radiation from their poles and rotates at a rate upto 716 times per second ( that's the fastest rate ) and they are so dense that a even a teaspoon of the material would weigh more than all of the fishes present on the Earth. Recently, the rate of the slowest spinning pulsar was 7.833 times per second and everyone thought that this would be the slowest among all.

But, now researchers have found a Pulsar rotating nearly at a rate of once every 23.5 seconds - nearly three times slower than the previous record holder. This Pulsar is located at some 14 million light-years away. This Pulsar is discovered by the team led by Chia Min Tan, a doctoral student from the University of Manchester. As part of the LOFAR ( Low Frequency Array ) tied-array all-sky survey, Tan and her colleagues searched the entire Northern sky and they found one in radio pulsar PSR J0250+5854.

The radiation emitted from the Pulsar can be observed if and only if the beam of emission is pointing towards the Earth. The first Pulsar was discovered on November 28, 1967 by Jacoelyn Bell Burnell and Antony Hewish. They observed pulses separated by 1.33 seconds that originated from a particular location in the sky.

The discovery was recognised by the award of the 1974 Nobel Prize in Physics, but despite the fact that Jacoelyn Bell Burnell was the first to observe the Pulsars, Bell was excluded from the recipients of the prize. But, finally after a long time, in 2018 Bell was awarded with the Special Breakthrough Prize and with the tittle - Women of the year 2018.

• What are Pulsars ?  

When a massive star - between 10 to 30 times the mass of the Sun - reaches the end of its nuclear-burning life, it goes out with an explosion as beautiful as an Supernova. though the vast majority the exploded star's material is blown outward during this violent event, it also causes the star's core to collapse itself, leaving behind an absurdly dense stellar corpse known as Neutron Star.

Gravitational Collapse of Core 

And because these Neutron Stars are so much smaller than their original progenitors, to conserve angular momentum, they must drastically increase their spin rate. Since these Neutron Stars also often have very strong magnetic fields, as the star quickly spins, the motion of its magnetic fields generates a powerful electrical field, which in turn accelerates nearby charged particles to incredible speeds. This produces powerful jets of radiation that are the hallmarks of Pulsars.

• What made PSR J0250+5854 so slow ?

Over time, the jets that shoot from a Pulsar's pole slowly rob the star of energy, which causes its spin to slow down. Eventually, after only about 10 - 100 million years, pulsars are believed to slow down to the point where the magnetic mechanism responsible for their jets shut down. At this stage Scientists say that Pulsar has reached the "Death Line". According to the study, the strange thing about the PSR J0250+5854 is that the Pulsar lies beyond conventional pulsar death line, where radio emission is expected to cease. 

This discovery was completely unexpected. All the researches across the globe are still a bit shocked. This discovery challenges and informs our theories for how Pulsars shine. 

Moving forward, the team will continue to analyse the data collected by the LOFAR survey, hoping to discover the new aspects of Pulsars and as far as PSR J0250+5854 is concerned, they plan to use ESA ( European Space Agency ) XMM-Newton space telescope to further study the object in greater detail. If the super-slow Pulsar is detected as the source of X-rays, then this will give important insights into its history and origin !