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The supermassive black hole at the center of the Milky Way, Sagittarius A*, keeps releasing random bursts of radiation on a daily basis and no one can figure out what is causing it. These bursts ranged from tens to hundreds of times brighter than the normal signals sent out by the supermassive black hole at the heart of our galaxy, but they don't appear to follow a discernable pattern. The data from 2006 to 2008 show high levels of gamma-ray activity, followed by a rapid four-year-long drop, after which activity shot back up, starting in 2012. There could be any...

The largest black holes in the universe... sit at the centers of almost every galaxy in the cosmos. Even the Milky Way has one, a monster at 4 million solar masses, designated as Sagittarius A*. ...[A]s far as we know, the only way to form black holes is through the deaths of massive stars. When they die, they leave behind a black hole a few times more massive than the sun. To get to supergiant status, they have to merge with other black holes and/or consume as much gas as possible, bulking up all those millions of solar masses... Either...

Black holes are most often discussed in terms of their mass, but how much volume do these hefty, invisible objects actually have? Lurking at the center of the Milky Way is a gargantuan black hole that tips the scales at several million times the mass of the Sun. Like all black holes, this supermassive monster — called Sagittarius A* — devours anything that falls too close, including light. However, consuming material is just one way these monsters grow to truly astronomical sizes, reaching mindboggling weights. Although astronomers often talk about black holes as being gigantic objects, it’s important to remember...

The supermassive black hole at the heart of the Milky Way, Sagittarius A*, is relatively quiet. It's not an active nucleus, spewing light and heat into the space around it; most of the time, the black hole's activity is low key, with minimal fluctuations in its brightness. When we view that radiation with a telescope using the infrared range, it translates as brightness. Normally, the brightness of Sgr A* flickers a bit like a candle, varying from minutes to hours. But when the surroundings of a black hole flare that brightly, it's a sign something may have gotten close enough...

A supermassive black hole has been found at the center of a tiny galaxy, a rare find. What makes the discovery even more unique is that it has been located in an ultracompact dwarf galaxy, stunning researchers. The findings, published in the Monthly Notices of the Royal Astronomical Society, note that the galaxy Fornax UCD3 is part of a set called ultracompact dwarfs (UCDs), a very rare set of galaxies. "We have discovered a supermassive black hole in the center of Fornax UCD3," said the study's lead author, Anton Afanasiev, in a statement. "The black hole mass is 3.5 million...

Explanation: The monster at the center of our Galaxy is about to get fed. Recent observations by the Very Large Telescopes indicate that a cloud of gas will venture too close to the supermassive black hole at the Galactic center. The gas cloud is being disrupted, stretched out, heated up, and some of it is expected to fall into the black hole over the next two years. In this artist's illustration, what remains of the blob after a close pass to the black hole is shown in red and yellow, arching out from the gravitational death trap to its right....

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2003 January 8 X-Rays from the Galactic Core Credit: Fred Baganoff (MIT), Mark Morris (UCLA), et al., CXC, NASA Explanation: Using the orbiting Chandra X-ray Observatory, astronomers have taken this long look at the core of our Milky Way galaxy, some 26,000 light-years away. The spectacular false-color view spans about 130 light-years. It reveals an energetic region rich in x-ray sources and high-lighted by the central source, Sagittarius...