On November 27, NASA shared a time-lapse footage of a stellar-mass black hole, about eight times the mass of the Sun, drifting away from its orbiting companion star and carrying out superluminal ejection in space. The outburst activity was occurring at 80 percent the speed of light, according to astronomers. Dubbed as the MAXI J1820+070, the black hole X-ray binary was discovered by the AstroSat spacecraft and its galactic flare-up was captured by NASA’s Chandra X-ray Observatory. Sharing the stunning visuals on twitter, NASA identified it as a stellar-mass black hole located 10,000 light-years from the planet Earth. Stellar-mass black holes form after they destroy and engulf the massive stars, NASA explained in a release.
“The companion star orbiting the black hole has about half the mass of the Sun. The black hole’s strong gravity pulls material away from the companion star into an X-ray emitting disk surrounding the black hole,” the Space Administration said.
NASA further informed that the hot gas ejected from the nucleus of the stellar-mass black hole would undergo a phenomenon called the “event horizon” where the gaseous material falls back into the black hole and diminishes forever. Meanwhile, the other type of the short beams of material, or jets are ejected away from the black hole in the magnetic lines surrounding the disk outside the event horizon. MAXI J1820+070 stellar-mass black hole’s behaviour was decoded via four sets of observations with Chandra and the research was published by scientist Mathilde Espinasse of the Université de Paris.
‘Superluminal motion’ in MAXI J1820+070
Observing the MAXI J1820+070 location from the Milky Way with PanSTARRS optical telescope in Hawaii, scientists found that the massive stellar-mass black hole was a point source of X-rays and jets that grew faint towards the south. Scientists studied the speed of jets composed of the hot material from the Earth’s perspective, saying, that the northern jet was moving at 60 percent of the speed of light, while at south the jets at “impossible-sounding 160 percent of light speed.” This phenomenon was termed as ‘superluminal motion’ by NASA scientists. “This means the object travels almost as quickly towards us as the light it generates, giving the illusion that the jet’s motion is more rapid than the speed of light,” NASA asserted in its finding. The MAXI J1820+070’s southern jet appears to be moving faster than the northern, proving that the high-speed expulsions appear several times faster than the light, although both jets are emitted at 80 per cent of the speed of light.
[Illustration of MAXI J1820+070. Credit: NASA’s Goddard]
Separately, a team led by Joe Bright from the University of Oxford observed the radio wavelengths of MAXI J1820+070 and discovered the superluminal motion in the stellar-mass black hole that occurred due to the launch of the jets. “Most of the energy in the jets is not converted into radiation, but is released when jets particles interact with surrounding material,” NASA explained. It added that when these jets collided with surrounding material in interstellar space, shock waves were created like the sonic booms caused by supersonic aircraft. This causes an estimated 400 million billion pounds of material ejecting out of the black hole, including the material accumulated on the disk. “Studies of MAXI J1820+070 and similar systems promise to teach us more about the jets produced by stellar-mass black holes and how they release their energy once their jets interact with their surroundings,” scientists concluded.