A telescope in Chile has photographed a new type of variable star 7,000 light-years away.
The newly discovered stars are marginally hotter than the sun and have not yet been named.
The European Southern Observatory was able to detect the star by looking at small changes of light in the cluster called NGC 3766. The new findings challenge current theories about the "origin of the variations."
A Swiss team used a relatively small, 3-foot-11 long telescope to observe the star cluster over a period of seven years.
The researchers regularly measured the brightness of the 3,000 stars in NGC 3766. The team noticed 36 of the stars followed a very strange brightness pattern. They would have small variations in brightness of about 0.1 percent every two to 20 hours.
"We have reached this level of sensitivity thanks to the high quality of the observations, combined with a very careful analysis of the data," Nami Mowlavi, leader of the research team, said in a press release. "But also because we have carried out an extensive observation program that lasted for seven years. It probably wouldn't have been possible to get so much observing time on a bigger telescope."
Changes in brightness have been seen in other stars, dubbed pulsating or variable stars. The change occurs from a complex reaction in the star's interiors.
"The very existence of this new class of variable stars is a challenge to astrophysicists," said Sophie Saesen, another member of the team. "Current theoretical models predict that their light is not supposed to vary periodically at all, so our current efforts are focused on finding out more about the behavior of this strange new type of star."
These variable stars have paved the way for an entire new branch of astrophysics called asteroseismolog, where scientists use stellar vibrations to find out more about the physical properties of the stars.
The cause of the varying brightness is yet to be discovered, but scientists do have one theory as to what's happening. Some of the stars rotate at incredible speeds; in fact they spin at a rate of more than half of their critical velocity. These stars spin so quickly they become unstable and toss material into space.
"In those conditions, the fast spin will have an important impact on their internal properties, but we are not able yet to adequately model their light variations," Mowlavi said. "We hope our discovery will encourage specialists to address the issue in the hope of understanding the origin of these mysterious variations."
