14 DAY TRIAL // The star was in fact known for a long time to be a magnetar, albeit SRON Netherlands Institute for Space Research astronomers have only recently discovered that it emits a strange high energy X-ray beam, sweeping across the surrounding medium as the star revolves around its axis.
"I was looking for new sources of high energy X-rays on a celestial chart, made using the space telescope INTEGRAL. To our surprise, at the edge of this chart a star was visible that we knew was a magnetar. However, we never expected that it would emit this type of radiation," said Peter den Hartog from SRON. Observations were conducted with ESA's INTEGRAL and XMM-Newton space telescopes and NASA's RXTE satellite.
Magnetars are neutron stars with extremely powerful magnetic fields, some of which are one billion times stronger that any man-made magnetic field generated on Earth. Simply put, no other known cosmic body in the universe surpasses the strength of their magnetic fields. Neutron stars can exceed masses of 1.5 times that of the Sun, and compress matter into a volume as small as 20 kilometers across.
Despite knowing a lot about neutron stars and how they form, with magnetars it's a whole different story. What is known is that during their lifespan, which can last as much as 10,000 years, they emit high amounts of X-rays as a result of their high rotation rate on their axis, and even though these X-rays are filtered by the Earth's atmosphere, they are nonetheless visible from space.
It was previously thought that the energy source of magnetars is released in the form of low energy X-rays, as the extreme internal magnetic field spirals through the star. However, a few years ago, SRON astronomer Lucien Kuiper, using the INTEGRAL satellite, discovered that magnetars emit much more energy than believed at the time. Again, magnetars fell into unknown territory.
"By converting the observations from INTEGRAL, XMM-Newton and RXTE into a type of short film, we could see how the characteristics of the X-rays changed over the course of time. Three different processes were found to be taking place in the magnetar that gave rise to three different pulses" accordingly to the rotation of the star, said De Hartog.
However, until NASA's GLAST space observatory, expected to be launched this June, reveals the results of its first investigation of the high energy radiation in the universe, the pulses emitted by the magnetar remain shrouded in mystery.