Astronomers believe they have taken images of a massive black hole tearing apart and swallowing a star.

Two papers released this week in the scientific journal Nature described how scientists using the Swift satellite observed a string of extremely powerful blasts of radiation from outside our galaxy that began March 25 and lasted two days. The brightness and behavior of the blasts could only be explained by a black hole tearing apart a sun-sized star, the authors say.

"It was nothing like we expected for a gamma-ray burst," said Ashley Zauderer, an astronomer at the Harvard-Smithsonian Center for Astrophysics who co-authored a different study on the event.

Additional observations by several radio telescopes suggested that the flare occurred in the center of a galaxy. The detector on the satellite picked up the burst of radiation coming from a point in the constellation Draco, 4.5 billion light years away from Earth.

Scientists have never caught black holes in the act of ripping apart a star although they have seen the aftermath of such an act before in the fading glows from distant galaxies.

"This was the first time we saw one of these big black holes going from quiet and silent to very loud and noisy, producing a lot of light and radiation," said Davide Lazzati, an astrophysicist at North Carolina State University who was not involved in the study.

Initially scientists thought the high-radiation burst was a supernova until Swift picked up two more bright bursts from the same spot. The patterns of higher and lower-energy radiation emitted over the next two days didn't match other space phenomena such as smaller black holes or spinning neutron stars.

Scientists finally concluded that the jets of radiation they observed could be best explained by a huge black hole destroying a star. The team believes that a star the same size as our sun moved too close to the black hole. The gravitational forces of the black hole eventually destroyed the star and in the process some of the star's material was expelled into a jet of high-energy radiation.

Future research could reveal more outbursts of this kind and help scientists figure out how many black holes of such strength lie in wait in the center of different galaxies.

"There are a lot more surprises in space for us to discover, especially as we continue to make huge strides in the technical capabilities of our instruments," Zauderer said.