Scientists are Baffled by Strange Infrared Signal Emanating from Space
Another day, another weird signal coming from deep in space that scientists can't really explain. NASA reports that a strange signal was recently detected by the Hubble Space Telescope. The signal seems to be coming from a nearby neutron star, but what sets it apart from other light signals in space is that for the first time, this strange signal is infrared.
In a study published in The Astrophysical Journal, an international team of researchers from Penn State, Sabanci University in Turkey, and the University of Arizona reports that the signal appears to be emanating from RX J0806.4-4123, a neutron star 800 light years away from Earth, but the amount of infrared radiation recorded in previous studies is more than the star should be emitting. "There's something more," lead author Bettina Posselt told Live Science. There are two theories as to what that something could be: a pulsar wind nebula, or what is known as a "fallback disc."
Animation of possible disc surrounding the neutron star. Credits: NASA, ESA, and N. Tr'Ehnl (Pennsylvania State University)
"A pulsar wind nebula would require that the neutron star exhibits a pulsar wind," explained Posselt in a statement. "A pulsar wind can be produced when particles are accelerated in the electric field that is produced by the fast rotation of a neutron star with a strong magnetic field. As the neutron star travels through the interstellar medium at greater than the speed of sound, a shock can form where the interstellar medium and the pulsar wind interact. The shocked particles would then radiate synchrotron emission, causing the extended infrared emission that we see. Typically, pulsar wind nebulae are seen in X-rays and an infrared-only pulsar wind nebula would be very unusual and exciting."
While the research team says that a pulsar wind emitting infrareds would be "definitely interesting," confirmation that the second source is a fallback disc would be a real game-changer. "Such a disk would be composed of matter from the progenitor massive star. Its subsequent interaction with the neutron star could have heated the pulsar and slowed its rotation," said Posselt. "If confirmed as a supernova fallback disk, this result could change our general understanding of neutron star evolution." Fallback discs could (in theory) stretch up to 18 billion miles across, but so far not a single one has been found.