Using NASA’s James Webb Space Telescope,
a team of astrophysicists has gained the longest,
most detailed glimpse yet of the void
that lurks in the middle of our galaxy.
They found that the swirling disk of gas and dust
orbiting the central supermassive black hole,
called Sagittarius A*,
is emitting a constant stream of flares with no periods of rest.
Using Webb’s NIRCam (Near-Infrared Camera)
to observe Sagittarius A* for a total of 48 hours
in 8- to 10-hour increments across one year,
astronomers saw constantly changing,
bubbling brightness, and then suddenly
a big burst of brightness popped up.
Then, it calmed down again.
They couldn’t find a pattern, it appeared to be random.
The activity profile of the black hole
was new and exciting every time that the astronomers looked at it.
While the team expected to see flares, Sagittarius A*
was more active than they anticipated.
The observations revealed ongoing fireworks
of various brightnesses and durations.
The accretion disk surrounding the black hole
generated five to six big flares per day
and several small sub-flares or bursts in between.
Although astrophysicists do not yet fully understand the processes at play,
they suspect two separate causes are responsible
for the short bursts and longer flares.
They believe that minor disturbances within
the accretion disk likely generate the faint flickers.
Specifically, turbulent fluctuations within the disk can compress
plasma to cause a temporary burst of radiation.
For the big, bright flares astronomers think the
cause is magnetic reconnection events,
a process where two magnetic fields collide, releasing
releasing energy in the form of accelerated particles.
Traveling at velocities near the speed of light,
these particles emit bright bursts of radiation.
These new findings could help physicists better
understand the fundamental nature of black holes, how they interact
with their surrounding environments,
and the dynamics and evolution of our own galactic home.
"Webb Space Telescope"
[ NASA Meatball ]