This visible-light picture of the Fireworks Galaxy (NGC 6946) comes from the Digital Sky Survey and is overlaid with knowledge from NASA’s NuSTAR observatory (in blue and inexperienced). NASA/JPL-Caltech
Utilizing X-ray knowledge from NASA’s NuSTAR area observatory, astronomers regarded to the delightfully named Fireworks galaxy (NGC 6946) and in contrast the X-ray sources (proven in blue and inexperienced) to the seen mild sources (the numerous stars proven throughout the picture). They had been aiming to review a supernova that was occurring within the galaxy and which reveals up as the brilliant blue spot within the higher proper.
However whereas they had been amassing knowledge, they observed one thing odd. The inexperienced blob on the underside facet of the picture wasn’t there of their first observations however was seen clearly in a second remark solely ten days later. After which within the subsequent set of observations, it was gone once more. That is very uncommon for a luminous X-ray supply, and it wasn’t accompanied by a corresponding improve in seen mild so it couldn’t be one other supernova. It was a puzzle the researchers needed to research.
“Ten days is a extremely quick period of time for such a brilliant object to seem,” Hannah Earnshaw, a postdoctoral researcher at Caltech and lead creator of the brand new examine, stated in an announcement. “Normally with NuSTAR, we observe extra gradual adjustments over time, and we don’t typically observe a supply a number of instances in fast succession. On this occasion, we had been lucky to catch a supply altering extraordinarily shortly, which may be very thrilling.”
Earnshaw’s examine means that the supply of the X-rays may very well be a black gap that was devouring a close-by star. As materials is pulled into the black gap from the disc of matter round it, it turns into extraordinarily sizzling and radiates X-rays. This course of normally goes on for a very long time as a result of black holes feed on stars progressively. On this case, it may very well be a black gap gobbling up a small star .
There’s one other risk although. The X-rays may very well be coming from a neutron star, which generates magnetic fields which might be robust sufficient to channel supplies to its floor. If a neutron star spins very quick, the magnetic fields can act like a barrier that stops materials from falling onto the star. “It will form of be like attempting to leap onto a carousel that’s spinning at 1000’s of miles per hour,” Earnshaw defined. The barrier may be stronger at some instances and weaker at others, and when it’s weaker it might permit matter by way of which might present up as X-ray bursts.
The researchers might want to proceed to watch the phenomenon to seek out out which concept is right. If the X-rays come again once more, it’s doubtless that the neutron star concept is right. If not, it was doubtless brought on by a black gap devouring a small star.
The findings are printed within the Astrophysical Journal.