One of the most magnetic objects in the universe had been silent for years. But when magnetar PSR J1622−4950 finally burst back to life, radio astronomer Fernando Camilo was without a telescope - until he remembered that he was commissioning one here in South Africa.
Without the new MeerKAT telescope, this science would not have been possible, Camilo says. The team’s observations were published on April 6 in The Astrophysical Journal, heralding the first MeerKAT-driven science publication.
Camilo, who is the chief scientist at the South African Radio Astronomy Observatory, had been keeping an eye on magnetars for years. “They are neutron stars that are barely stable - they have the strongest magnetic fields in the universe,” he explains. Normal neutron stars’ magnetic fields are a trillion times stronger than Earth’s; magnetars’ are a thousand times stronger than that.
PSR J1622−4950, one of only four magnetars known to produce radio waves, had been dormant for three years, but when it came back to life in April last year “it was like a big star quake”.
But the Australian Parkes telescope, with which Camilo had been observing magnetars, was about to shut down for month-long maintenance, and this particular magnetar can only be seen in the Southern Hemisphere. During these outbursts, the magnetars’ magnetic fields realign, and they give off firework-like bursts of radiation every four seconds.
Camilo, who had been about to catch a plane when he found out about the magnetar, says: “Midway over the Indian Ocean, I realised we had a telescope we could possibly use: It’s called MeerKAT!”
South Africa's 64-dish MeerKAT telescope, which became fully science-ready this month, will form part of the Square Kilometre Array, which will be the largest radio telescope on Earth. In conjunction with observations from scientists from the Australia, Canada, France, and New Zealand, their paper details the revival of this enigmatic celestial object.
“It was only the second outburst ever detected from this source from its known history. Without MeerKAT, we would not have done this,” Camilo says.