New York — Scientists have observed what appear to be two stars rotating, one around the other, near the supermassive black hole at the center of the Milky Wayour galaxy.
Almost all large galaxies have a supermassive black hole at their core. The one located in the center of the Milky Way, called Sagittarius A (asterisk), has a mass approximately 4 million larger than that of our sun and it is relatively quiet; From time to time it swallows gas or dust that passes nearby.
Scientists know that stars can form near and even orbit these colossal black holes, but they have never seen a pair of stars survive so close.
The research was published Tuesday in the Nature Communications magazine.
The celestial sighting is interesting and unusual, and more research is needed to be sure what these objects are, said astrophysicist Anna Ciurlo of the University of California, Los Angeles.
“This leaves some questions still open,” said Ciurlo, who was not involved in the new research.
At about 2.7 million years old, the twin stars appear to be quite young. Scientists said they appear to orbit each other at just the right distance: if they were too far apart, the black hole’s gravity would pull them further apart. If they were closer, they would merge into a single star.
Still, the cosmic duo won’t remain stable forever. The two stars could end up merging, although the timing is uncertain, said the study’s lead author, Florian Peissker of the University of Cologne.
“We really are in a very fortunate situation,” he said. “We looked at the system just in time.”