There is a supermassive blackhole named Sagittarius A* right at the center of the Milky Way or the Galactic Center.
Our Milky Way galaxy is centered around a vast expanse: 300 billion stars in the Orion Spur, which will take more than 25,000 years to explore. The trouble is we can barely fully understand and appreciate the grand expanse of cosmos from Earth; we might have to take an excursion to the galaxy’s center to get a better picture.
The process of getting to know what could be at the center of our home galaxy is an incredible journey. Let’s explore.
Discovery of the Sagittarius A*
In 1933, an American radio engineer Karl Jansky noticed a radio signal coming from the constellations of Sagittarius. Even though Jansky confirmed our suspicions, astronomers were not entirely in the dark about Sagittarius A*. They had figured out the presence of some entity in the middle based on their calculations of globular cluster velocities and positions, which seemed to revolve around a common point.
Image & Speculations
Even with all our telescopes pointed towards the proposed center, some 27,000 light-years were not enough to reveal much because of thick smokey dust clouds that conceal the center of the Milky Way. We only got lucky until we got blessed with Jansky’s discovery.
Sagittarius A*: As We Know It Now
We haven’t still been able to see it clearly, although hopes are we will soon get a more detailed infrared picture taken by the James Webb Telescope. In the picture above, all we can see is the glowing gas cloud around the supermassive black hole, making it appear like a doughnut-shaped ring.
Basis for Alternate Explanations
Sagittarius A* is a relatively calmer gigantic black hole, very unlike other supermassive blackholes that we have found so far Some researchers have indicated that the mass of Sagittarius A* is abnormally low for galaxies the size of the Milky Way. We do not know why, but there might be an entirely different proposition that can explain the seemingly unpredictable behavior of the black hole at the center of the Milky Way.
In late 2021, some astrophysicists from Italy, Argentina, and Colombia came together to pen a paper claiming they have proof that the center of our galaxy is not a black hole but rather a dense fog of dark matter.
These scientists have taken their backing on the observation of Sagittarius A* in 2014, when a galactic object orbiting the center of the Milky Way passed its closest point to the middle and became stretched out and distorted — a phenomenon known as drag. Scientists from the International Center for Relativistic Astrophysics in Italy say this is a sign that Sagittarius A* might be something other than a supermassive black hole.
Each theory about what lies in the center of the Milky Way galaxy has strong proponents, as there is evidence for both. However, time will tell what actually resides there. Till then, we are welcome to speculate.