Love a good mystery? Look no further than Fast Radio Bursts, one of the hottest topics in the world of astronomy. These enigmatic pulses of low frequency radiation emit tremendous energy and seem to appear randomly and disappear rapidly, lasting only for about a millisecond. We don’t as yet know exactly what causes them, when to expect them or where in the universe they are likely to occur. Since the first Fast Radio Bursts, or FRBs as they are known, were discovered in 2007 more than sixty have been detected.
About two years ago researchers led by Shami Chatterjee of Cornell University made the exciting discovery of repeating FRBs coming from a dwarf galaxy 3 billion light-years from earth. And just last month a group of researchers from several Canadian universities reported the discovery of another FRB repeater about 1.5 billion light-years away.
Given these two recent discoveries it seems likely that there are many more Fast Radio Burst repeaters out there. But what causes them remains a mystery. Analysis of the signals from the FRB repeater detected two years ago suggests that they were generated by intensely powerful magnetic waves, but if so, what was their source? Data from the more recent set of repeaters suggests the radio waves were scattered by whatever surrounds the source, perhaps clumps of gas or dust from an exploded star.
While Fast Radio Bursts are thought to emanate from beyond our galaxy a clue to their nature may be found in the recent detection of radio wave pulses coming from an object close to the supermassive black hole at the center of our own galaxy. The object is a magnetar, a rotating, dense, dead star with a powerful magnetic field. The new research, led by scientists from Caltech and the Jet Propulsion Laboratory, suggests that magnetars similar to this one, positioned close to a black hole, could be a source of Fast Radio Bursts.
According to Aaron Pearlman of Caltech, “Our observations show that a radio magnetar can emit pulses with many of the same characteristics as those seen in some FRBs. Other astronomers have also proposed that magnetars near black holes could be behind FRBs, but more research is needed to confirm these suspicions.”
A magnetar is a rare kind of pulsar which, in turn, is a type of rotating, dead star known as a neutron star. It is thought that magnetars are young pulsars that spin more slowly than regular pulsars and have much stronger magnetic fields.
The magnetar observed by the Caltech-led team is the closest known pulsar to the supermassive black hole at the center of our Milky Way galaxy. It is only 0.3 light-years from the black hole, and is the only pulsar known to be gravitationally bound to the black hole and the region around it.
While there is still much conjecture as to the cause of Fast Radio Bursts there’s been nothing to suggest that these might be anything other than natural cosmic events, so we can rule out aliens. As of now, we’re still waiting for them to be in touch.
Join the Springfield Stars Club on Tuesday, February 26th at 7pm at the Springfield Science Museum for a talk by Richard Sanderson on “David Todd: Amherst’s Flamboyant Astronomer.” This adventurous astronomer from a century ago traveled the world to witness eclipses and was responsible for building Amherst College’s Wilder Observatory. Richard Sanderson is the recently retired curator of physical science at the Springfield Science Museum and a long time member of the Springfield Stars Club. He is an astronomy writer and co-author of the 2006 book, “Illustrated Timeline of the Universe.” Refreshments will be served, and the public is welcome. The meeting is free of charge for members, with a suggested donation of $2 per non-member.
Also, on Friday, March 1st at 7:30pm, the Stars Club and the Springfield Science Museum will host “Stars over Springfield,” an astronomy adventure for the whole family. Amateur astronomer Ed Faits will give a talk on “Comets, Asteroids and other Wanderers.” A fee of $3 for adults and $2 for children under 18 will be charged.
Copyright © Amanda Jermyn