Astronomers from UCLA have solved the puzzle surrounding a bizarre object at the center of our galaxy. Latest research suggests that a massive black hole drove two binary stars to merge into one. The answer comes after several years that left astronomers seeking answers. Up until now, it was believed that the object in the center of the Milky Way was a hydrogen gas cloud headed towards our galaxy’s large black hole.

Now, astronomers believe they have found an answer to the puzzle, largely known as G2, having studied it in its closest approach to the black hole this summer.

The team, led by Andrea Ghez, professor of physics and astronomy in the UCLA College, found that G2 is most likely a pair of binary stars that had been orbiting the black hole together, ultimately merging into a very large star surrounded by gas and dust. The object’s movements were dictated by the black hole’s powerful gravitational field. The research was published on November 3 in the journal Astrophysical Journal Letters.

Ghez, who holds the Lauren B. Leichtman and Arthur E. Levine Chair in Astrophysics, said in a statement, “G2 survived and continued happily on its orbit; a simple gas cloud would not have done that.” He continued, “G2 was basically unaffected by the black hole. There were no fireworks.”

Ghez, a 2008 MacArthur Fellow, explained that black holes, which form from the collapse of matter, have such a high density that nothing can escape their gravitational pull, even light. She says that although they cannot be seen directly, the influence black holes have on nearby stars is visible and provides a signature.

According to NASA, most black holes form from the remnants of a large star that dies in a supernova explosion.