A dead star over 12 million light-years away is giving off enough light in pulses that it breaks the Eddington limit, a law of physics that outlines the maximum brightness an object can give off based on its mass.
Because of the x-ray emissions the dead star is releasing, astronomers once thought it was a black hole. However, NASA's NuSTAR telescope recently identified it as a pulsar, a highly magnetized dense rotating collapsed star.
Generally speaking, pulsars are only about one or two times the mass of our sun. This new pulsar fits into that size, but it's x-ray emissions are 100 times brighter than normal. This easily breaks the Eddington limit, and is perplexing scientists.
"We've never seen a pulsar even close to being this bright," says Dom Walton, who works with NuSTAR data. "Honestly, we don't know how this happens, and theorists will be chewing on it for a long time."
This pulsar is located in a galaxy called M82 or the "Cigar Galaxy," given its name for its shape. Astronomers recently detected this supernova, which resulted in telescopes all over the world being pointed in its direction. There were also other extremely bright x-ray sources coming from this galaxy, suggesting that the galaxy harbored black holes.
However, after taking a closer look with NuSTAR, astronomers noticed that the collapsed star was pulsing once every 1.37 seconds. However, black holes don't pulse. But pulsars do.
After double-checking their data, astronomers now believe this dead star is a pulsar. But its relatively small mass created a conundrum. According to what we know, something as small as this pulsar cannot be this bright. And that is not only puzzling scientists, but also possibly changing certain laws of physics.
It could be that this pulsar is just a strange, unique sort of anomaly. Or it could be that the Eddington limit is wrong. And if that's the case, many objects previously identified as black holes may, in fact, be pulsars.
"This is going to be a problem challenging theorists when they read this result," says Jeanette Gladstone, of the University of Alberta in Canada.
Considering that some scientists are questioning if black holes really exist, at least in the way we think they do, perhaps this, along with other puzzling discoveries, will lead to a new understanding of the mechanics of these mysterious objects of the cosmos.