Mysterious colourful lights spotted
- The primary goal of the NuSTAR observations was to look at the supernova – explosion of a huge star.
- The green blob, which is known as ultraluminous X-ray source (ULX), near the bottom of the galaxy did not feature during the first observation. However, it appeared during a second observation after 10 days.
- Another NASA telescope called Chandra X-ray Observatory took a look at it again and found the object that had quickly disappeared. This object has been named as ULX-4 because it is the fourth ULX identified in this galaxy.
- According to the study, it can be possible that the light was from a black hole consuming another object like a star. When an object gets too close to a black hole, it can get pulled apart by gravity, and the debris gets pulled into a close orbit around the black hole.
- The material at the disk’s inner edge starts moving so quickly that it gets heated up to millions of degrees and radiates X-rays, NASA explained. For comparison, the surface of the Sun is around 10,000 degrees Fahrenheit or 5,500 degrees Celsius.
- Most ULXs typically last longer because they are formed by dense objects like black holes that “feed” on a star for an extended time. Short-lived or transient X-ray sources like this particular ULX are not common, so its appearance could be explained by a scenario such as a black hole quickly destroying a small star.
- However, this ULX may not be a single event, The study’s authors suggest that its source may be a neutron star- which is an extremely dense object created from the explosion of a star that wasn’t big enough to create a black hole. Like black holes, neutron stars can pull in material and cause debris to move really fast in a disk.
- Neutron stars can generate such strong magnetic fields which make “columns” that channel material down to the surface. These generate powerful X-rays in the process. But if the neutron star spins especially fast, material cannot reach the surface and create these X-ray bursts.
- This result is a step towards understanding some of the rarer and more extreme cases in which matter accretes onto black holes or neutron stars.
- The Nuclear Spectroscopic Telescope Array (NuSTAR) is a National Aeronautics and Space Administration (NASA) Small Explorer mission that carried the first focusing hard X-ray (6-79 keV) telescope into orbit.
- It was launched on a Pegasus rocket into a low-inclination Earth orbit on June 13, 2012, from Reagan Test Site, Kwajalein Atoll.
- The NuSTAR observatory is composed of the X-ray instrument and the spacecraft. The NuSTAR spacecraft is three-axis stabilized with a single articulating solar array based on Orbital Sciences Corporation's LEOStar-2 design.
- The NuSTAR science instrument consists of two co-aligned grazing incidence optics focusing on to two shielded solid state CdZnTe pixel detectors.
- The NuSTAR observatory operated out of the Mission Operations Center (MOC) at UC Berkeley.