Its orbit is about the same size as Mercury’s, but it moves at a speed that is just 30% as fast as light.
The globe was stunned when the Event Horizon Telescope Collaboration revealed an image of what appeared to be a streaky French cruller on fire in May. This wasn’t a doughnut at all. Sagittarius A*, the massive black hole that serves as the galaxy’s anchor and whose gravitational pull silently brushes every star, planet, and asteroid within, was depicted in this perplexing way.
This was the first time we had ever seen her majesty, which was an amazing moment in and of itself, but the scientists weren’t finished yet. Sgr. A* had much more to teach us.
Astronomers have been closely monitoring and researching the emptiness from Earth’s perspective, about 27,000 light-years from this black hole, in an effort to understand exactly how the Milky Way’s fierce engine functions. And just last month, a team using the Atacama Large Millimeter/submillimeter Array Observatory, a potent radio telescope, discovered some intriguing hints.
The researchers discovered what it refers to as a “hot spot” flying around the abyss after examining ALMA data collected in conjunction with EHT observations of Sgr A. They claim that this point appears to darken and brighten as it circles Sgr A in a clockwise direction.
The study’s lead author, Maciek Wielgus of the Max Planck Institute for Radio Astronomy in Germany, said in a statement, “We think we’re looking at a hot bubble of gas zipping around Sagittarius A* on an orbit similar in size to that of the planet Mercury, but making a full loop in just around 70 minutes.”
In order to put things into perspective, one circle of the sun takes Mercury 88 Earth days to complete. Mercury is also the fastest planet, moving at almost 29 miles per second.
Wielgus noted that it was astonishing that the hot ball of gas needed to travel at a rate that was “mind-bogglingly close to 30% of the speed of light” in order to completely circle Sgr A* in only 70 minutes.
Additionally, according to the researchers, the bubble’s orbit is located at a distance from the nothingness that is around five times greater than the event horizon of a black hole. In essence, every black hole has a boundary beyond which light cannot escape. It represents the clear separation between what is inside the beast and what is in our apparent universe. The event horizon is there.
What is the significance of this bubble?
According to the European Southern Observatory, the study’s researchers believe that the newly discovered hot area is related to flares or bursts of X-ray energy emitted from the Milky Way’s centre. This is the first time anyone has found them with radio telescope data — and with a “quite strong indication” at that. In fact, similar flares have been spotted in the past by both X-ray and infrared investigations of Sagittarius A*.
It’s possible that the different wavelengths’ characteristics are altering with time, which is why we observe this energetic activity at X-ray, infrared, and radio frequencies.
According to Jesse Vos, a Ph.D. student at Radboud University in the Netherlands and a co-author of the study, “Perhaps these hot spots detected at infrared wavelengths are a manifestation of the same physical phenomenon: as infrared-emitting hot spots cool down, they become visible at longer wavelengths, like the ones observed by ALMA and the EHT.”
The team’s latest research also seems to support a different long-held idea, according to which flares emitted from the Milky Way’s centre are caused by magnetic interactions with hot plasma spinning close to Sgr A*.
“Now that we have good evidence for the magnetic genesis of these flares, we can learn more about the geometry of the process from our observations. The new information is very beneficial for developing a theoretical explanation of these events, “Co-author of the study Monika Mocibrodzka from Radboud University stated in a release.
The researchers says that these interpretations might provide us a glimpse of the mysterious black hole’s overall magnetic field or information about the surroundings of the odd hot spot. In the end, perhaps they will be able to depict what is actually happening in the Milky Way’s nucleus, which is a massive black hole’s home and a region of silent chaos.
Ivan Marti-Vidal of the University of Valencia in Spain, a co-author of the study, said in a statement that in the future, utilising coordinated multi-wavelength observations with both GRAVITY and ALMA, they should be able to monitor hot spots across frequencies.
The accomplishment of such a project would mark a significant turning point in our knowledge of the physics underlying flares in the Galactic centre.