14 DAY TRIAL // Dutch astronomers using the International Low-Frequency Array (LOFAR) Telescope (ILT), in the Netherlands, announce the discovery of two fast-moving pulsars that were previously unknown to science. The objects were discovered as the radio observatory was warming up for its all-sky survey.
Details of the research were presented by astronomer Thijs Coenen on November 20, as he defended his PhD thesis based on LOFAR data at the University of Amsterdam. The two pulsars were revealed to be relatively weak, but fast-spinning.
A pulsar is a type of neutron star that boasts a powerful magnetic field. Unlike conventional neutron stars, it spins incredibly fast around its axis, and emits a beam of electromagnetic radiation throughout the spectrum as it does so. Viewed from Earth, such a star resembles a lighthouse, hence its name.
A neutron star is the extremely dense core of a former massive or supermassive star, which collapsed at the end of its main sequence. Astronomers say that a star has to be at least 8 times more massive than our Sun in order for it to have a chance at forming a neutron star when it dies, SpaceRef reports.
Their cores compact after supernova blasts that remove the outer layers of their atmosphere. Once formed, a neutron star has a diameter of only 20 miles (32 kilometers), which packs the mass of several Sun. A single teaspoon of material from a neutron star can weigh 100 trillion tons.
LOFAR was developed and built by the Netherlands Institute for Radio Astronomy (ASTRON), and represents an extremely sensitive tool for pulsar research. It is most responsive to radio frequencies between 30 and 1.3 meters in the electromagnetic spectrum.
This observatory is the first built on a new principle, which connects vast array of omni-directional antennas together in a telescope with a diameter of more than 1,000 kilometers (621 miles). LOFAR features in excess of 20,000 dipole antennae.
The telescope's capabilities will be further extended by the upcoming Square Kilometre Array (SKA), the largest radio observatory in the world, currently under construction.
“SKA will take LOFAR technology one step further, and these discoveries show we can expect to detect a large fraction of the pulsars in our galaxy with SKA,” says research leader Jason Hessels, who is based at both the University of Amsterdam and ASTRON.