NASA has discovered something mysterious in space that can not be fully explained – bright flashes of green and blue spots that appeared and disappeared in a cosmic second.
The NuSTAR X-ray Observatory looked at the fireworks galaxy (NGC 6946) and saw several blue and green spots of light that appeared and disappeared within a few weeks, according to a new study published in the Astrophysical Journal. NASA's Chandra X-ray Observatory has also witnessed the appearance and disappearance of the Green Blob, known as the Ultraluminous X-ray Source (ULX), which confirms the sighting.
"Ten days are a really short time for such a bright light object to appear," said Hannah Earnshaw, a postdoctoral fellow at Caltech, in a statement. "Normally, with NuSTAR, we observe more gradual changes over time, and we often do not watch a source multiple times in a row. In this case, we were fortunate to find a source that changes extremely fast, which is very exciting.
While researchers quickly point out that ULXs are a common occurrence in space (this was the fourth discovered in this galaxy). They also find that ULXs are "typically long-lived." This ULX detected "visible light … with the X-ray source," which probably excludes the possibility that it is a supernova.
So, what is it? ? The researchers uncovered several theories about the appearance of the Green Blob, including the fact that it could be a black hole picking up another object.
"If an object gets too close to a black hole, gravity can pull that object apart and put the debris into close orbit around the black hole," NASA wrote in the post. "The material on the inside edge of this newly formed disc is starting to move so fast that it heats up to millions of degrees and emits X-rays."
Given that ULX-4 could be a recurring event, this is another possible explanation that it is a neutron star. Neutron stars, which are roughly the same mass as the Sun, can attract material to form debris disks that can produce ULX sources.
However, if the neutron star rotates too fast, the magnetic fields it generates can actually create a barrier that would prevent the material from reaching the surface of the star.
"It would be like jumping on a carousel that spins at a speed of thousands of miles per hour," Earnshaw added.
The barrier effect would prevent the star from being an X-ray source. However, the barrier could "wobble" briefly, causing material to land on the surface of the neutron star and land there, which could explain the sudden appearance and disappearance of the ULX, the researchers suggested.
"This result is a step towards understanding some of the rarer and more extreme cases in which matter accumulates on black holes or neutron stars," Earnshaw said.