How a cloud could survive an encounter with a black hole
A black hole isn’t the safest neighbor to have. Anything that crosses the event horizon will be pulled in, possibly being ripped apart in the process. So when a presumed dust-cloud, known as G2, was seen in orbit around the huge black hole at the center of the Milky Way, astronomers expected it to be shredded and consumed. When G2 survived its peribothron, or black-hole-fly-by, some new hypotheses were needed.
A star hidden in a cloud
The first guess for what could survive moving within range of the black hole, but still appear on telescopes with the fuzzy boundaries of a dust cloud, was a pair of stars being mashed together thanks to the black hole’s gravity. The merging bodies could have enough mass to hold themselves together for the most part while some dust and gas was expelled in the chaos of that process.
The second guess is that G2 is a very young star, still in the process of accumulating material. Again, there’s a core of mass to survive the peribothron, and the cloudiness is just the remaining gas and dust that the star has yet to suck up.
Whatever G2 turns out to be, it’s moving at an amazing speed, thanks to being whipped about by the black hole. Perhaps swinging out to the far point in its orbit will give it the breathing room needed to finally congeal into a more easily recognized object.
Source: What Kind of Object Can Survive a Close Encounter With a Monster Black Hole? by Phil Plait, Bad Astronomy