Washington: NASA may have captured screams of dead stars as they feed on the stellar companions with the help of a Nuclear Spectroscopic Telescope Array, or NuSTAR.
Peering into the heart of the Milky Way galaxy, NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) has spotted a mysterious glow of high-energy X-rays that, according to scientists, could be the “howls” from Zombie Stars.
Astronomers have four potential theories to explain the baffling X-ray glow, three of which involve different classes of stellar corpses. When stars die, they don’t always go quietly into the night.
Unlike stars like the sun, collapsed dead stars that belong to stellar pairs, or binaries, can siphon matter from their companions. This zombie-like “feeding” process differs depending on the nature of the normal star, but the result might be an eruption of X-rays.
According to one theory, a type of stellar zombie called a pulsar could be at work. Pulsars are the collapsed remains of stars that exploded in supernova blasts.
They could spin extremely fast and send out intense beams of radiation. As the pulsars spin, the beams sweep across the sky, sometimes intercepting the Earth, like lighthouse beacons.
Other possible culprits include heavy-set stellar corpses called white dwarfs, which are the collapsed, burned-out remains of stars not massive enough to explode in supernovae. The sun is such a star, and is destined to become a white dwarf in about five billion years.
Because these white dwarfs are much denser than they were in their youth, they have stronger gravity and can produce higher-energy X-rays than normal. Another theory points to small black holes that slowly feed off their companion stars, radiating X-rays as material plummets down into their bottomless pits.
Alternatively, the source of the high-energy X-rays might not be stellar corpses at all, astronomers stated, but rather a diffuse haze of charged particles, called cosmic rays. The cosmic rays might originate from the supermassive black hole at the centre of the galaxy as it devours material. When the cosmic rays interact with surrounding, dense gas, they emit X-rays.
However, none of these theories match what was known from previous research, leaving the astronomers largely stumped.