The first-ever observation of a star being engulfed by a black hole and
releasing a burst of matter traveling almost as fast as light has been made
by a multinational team of astrophysicists under the direction of a
scientist from Johns Hopkins University.
According to Sjoert van Velzen, a Hubble fellow at Johns Hopkins, the
discovery, which was published on Thursday in the journal Science, follows
the star—roughly the size of our sun—as it deviates from its usual course,
enters a supermassive black hole's gravitational attraction, and gets pulled
in.
Van Velzen stated, "These occurrences are incredibly uncommon." "We watched
it unfold over several months, and it's the first time we see everything
from the stellar destruction followed by the launch of a conical outflow,
also called a jet."
Black holes are regions of space that are so dense that matter, gas, and
even light cannot escape due to an insurmountable gravitational pull. As a
result, the area seems to be empty and lacks visibility. It has long been
known by astronomers that if a black hole is forced to consume a significant
amount of gas—in this example, an entire star—it will release a fast-moving
jet of plasma, which are simple particles trapped in a magnetic field, from
its vicinity around the black hole's "event horizon." The experts noted that
this analysis implies that their prognosis was accurate.
Lead analyst Van Velzen oversaw the work of 13 other scientists from the
US, the Netherlands, Australia, and Great Britain. "Previous efforts to find
evidence for these jets, including my own, were late to the game," van
Velzen said.
Most huge galaxies are thought to contain supermassive black holes, which
are the largest type of black holes. With barely a million times the mass of
the sun, this specific supermassive black hole is on the lighter end of the
spectrum yet still has the power to devour a star.
Using an optical telescope in Hawaii, a team from Ohio State University
made the first observation of the star being destroyed. Early in December
2014, that team took to Twitter to proclaim their discovery.
Van Velzen got in touch with Rob Fender's astrophysics team at the
University of Oxford in Great Britain after reading about the incident. To
follow up as quickly as possible, that group employed radio telescopes. They
happened upon the event barely in time.
By the time it was finished, the multinational team had assembled data from
radio, optical, and X-ray signals using ground-based observatories and
satellites, creating a breathtaking "multi-wavelength" depiction of this
event.
The fact that the galaxy in question is nearer Earth than others
investigated earlier made it easier to trace a jet that emerges when a star
is destroyed. The other galaxies were at least three times further away than
this one, which is located roughly 300 million light years distant. It is
5.88 trillion miles per light year.
An "accretion disk" is an enormous spinning mass that arises when a black
hole takes in matter from space. The multinational team's initial step was
to rule out the idea that the light came from this type of pre-existing
disk. That made it easier to verify that a recently imprisoned star was the
cause of the galaxy's abrupt surge in brightness.
Van Velzen stated, "The demise of a star by a black hole is exquisitely
complex, and far from understood." "Our observations reveal that the streams
of stellar debris can quickly organize and form a jet, which is important
information for developing a comprehensive theory of these events."
Van Velzen examined jets from supermassive black holes for his PhD
dissertation at Radboud University in the Netherlands, which he finished
last year. He stated in the last sentence of the dissertation that he hoped
to find out about these occurrences in four years. As it happened, the time
it took for his dissertation defense was only a few months following the
ceremony.
It wasn't only Van Velzen and his group searching for radio signals from
this unfortunate star. Harvard researchers used radio telescopes in New
Mexico to examine the same source, and they published their findings online.
Early in November, both teams presented their findings in a workshop in
Jerusalem. The two rival squads have never faced each other in person
before.
Van Velzen described the encounter as "an intense, yet very productive
exchange of ideas about this source." "We still get along great; in fact,
the leader of the rival group and I went on a long hike close to the Dead
Sea."
Provided by
Johns Hopkins University
