Black holes are known to gobble up stars voraciously, due to their intense gravitational pull, and emit streams of matter at nearly the speed of light. A new study has, however, dispelled this long-believed notion.
A team of astronomers from the University of Florida has published a paper, in the journal Science, which indicates the magnetic fields of black holes are not that powerful.
Black Hole V404 Cygni
The scientists conducted the study after getting a rare opportunity to measure the magnetic field of a black hole referred to as V404 Cygni. It is located 8,000 light years away from Earth and has a width of 40 miles.
The measurements were developed from data collected in 2015 when V404 Cygni’s had a rare outburst of jets. The lens mirror of the 34-foot Gran Telescopio Canarias in Canary Islands, Spain was used to observe the event.
The research team found that V404 Cygni’s magnetic energy is around 400 times less than it was crudely estimated before. V404 Cygni’s measurements have enabled scientists to know more about how black holes’ magnetism works.
The measurements will also enable researchers to solve the puzzle of how jets of particles traveling at approximately the speed of light are emitted out of the magnetic fields of black holes, while every other thing gets vacuumed into their abysses.
"Our surprisingly low measurements will force new constraints on theoretical models that previously focused on strong magnetic fields accelerating and directing the jet flows,” said Stephen Eikenberry, co-author of the study. “We weren't expecting this, so it changes much of what we thought we knew."
Smaller black holes, like the V404 Cygni which produce jets, are the rock stars of galaxies. Their outburst is sudden and short-lived, for instance, V404 Cygni’s outburst lasted for only a few weeks and before that, its last outburst was in 1989.
The study findings have deepened the knowledge of how matter behaves in the most extreme conditions. The knowledge can also widen the limits of GPS systems and nuclear fusion power in the future.
Black Hole Size
Scientists believe that black holes come in various sizes. Supermassive black holes are the ones that have a mass million to billion times more than the sun, measuring about the Solar System’s size. They are present in the center of all massive galaxies and possibly play a decisive part in its formation and evolution.
Then, there are black holes that are only about slightly more massive than the sun. The merger of dense remains of stars like neutron stars, the collision of a neutron star with another stellar black hole or the cataclysmic death throes of massive stars form them. Gravitational waves are produced when they merge.
However, even the closest supermassive black hole is nearly 30,000 light years away from Earth, so it is challenging for scientists to study their magnetic fields. Fortunately, the V404 Cygni is comparatively closer and can help scientists study the feeding of black holes and cosmic indigestion.