Sagittarius A Star

When Astronomers use the term Sagittarius A Star they refer to a very dense very massive object in the center of the Milky Way, our galaxy.^[1] Astronomers believe all large galaxies have a supermassive black hole at their centre, and Sagittarius A Star is our galaxy's black hole.

Radio Astronomers were the first to observe a very intense source of radio waves at the center of our galaxy.^[1] Observing it with visible light challenged the telescopes until recently, due to interstellar dust.

Astronomers have noticed there is a cluster of stars near where they expected to find Sagittarius A Star, that had orbits that could only be explained if they were orbiting a very massive object.^[1]

An alternate explanation is that Sagittarius A Star is not a black hole, instead being a massive knot of dark matter.^[1]

References

↑ ^1.0 ^1.1 ^1.2 ^1.3 "Sagittarius A* Might Not Be a Black Hole". Milky Stellar. 2026-06-21. Retrieved 2026-08-09 – via YouTube. At the center of our galaxy sits a monster, a supermassive black hole four million times the mass of the Sun, photographed for the first time in 2022 and hailed around the world. There's just one problem. We have never actually proven it's a black hole. In February 2026, a team of physicists in Argentina proposed something stranger. What if the most famous black hole in the galaxy isn't a black hole at all — but an enormous, invisible sphere of dark matter, the mysterious substance that makes up most of the universe? Their model reproduces the orbits of the stars at the galactic center so precisely that, with the data we have today, you simply cannot tell the two apart. If it's true, it would mean that two of the deepest mysteries in all of science, what lies at the heart of our galaxy, and what dark matter is actually made of — are the same mystery, with the same answer, hiding in the same place.

[MilkyStellar-2026-06-21-1] 1.0 ^1.1 ^1.2 ^1.3 "Sagittarius A* Might Not Be a Black Hole". Milky Stellar. 2026-06-21. Retrieved 2026-08-09 – via YouTube. At the center of our galaxy sits a monster, a supermassive black hole four million times the mass of the Sun, photographed for the first time in 2022 and hailed around the world. There's just one problem. We have never actually proven it's a black hole. In February 2026, a team of physicists in Argentina proposed something stranger. What if the most famous black hole in the galaxy isn't a black hole at all — but an enormous, invisible sphere of dark matter, the mysterious substance that makes up most of the universe? Their model reproduces the orbits of the stars at the galactic center so precisely that, with the data we have today, you simply cannot tell the two apart. If it's true, it would mean that two of the deepest mysteries in all of science, what lies at the heart of our galaxy, and what dark matter is actually made of — are the same mystery, with the same answer, hiding in the same place.

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