Astronomers Find New Star With Record Variation Period

A star was discovered by scientists at Lomonosov Moscow State University. They used a global network of robot telescopes to locate one star brighter than others. As it faded significantly, there are questions about whether it was "a binary star", or whether it just faded in the natural flow of events.

This network of telescopes is also called the MASTER network. It was created in order to locate gamma-ray bursts or the most energetic flashes in the world. However, the researchers used MASTER and discovered another kind of star.

Astronomers three years ago found a giant bright star called TYC 2505-672-1 that faded so much that its brightness had dimmed about 100 times.

While experts did not believe that the fading was important, as these things are habitual in the universe, they could not figure out the reasons for the dimming. They surmised  that perhaps a red giant spewed a cloud of stardust made of carbon particles, which blocked it from view.

As the star did not turn red, the researchers looked at it closely. They found that it became a "record-breaker" in a length of variation period for about 69 years. The longest known variation period was earlier part of Epsilon Aurigae, with its repeated eclipses in every 27 years.

"Ironically, the project MASTER, initially intended for observing fast happening phenomena, such as for example the consequences of the Gamma-ray bursts and star flashes, discovered an unprecedented variability of a tally different scale," said Denis Denisenko, one of the researchers involved in the study. "The scale of the new object is already impressive. Giant stars of such spectral class are about three and a half times heavier than the sun. Taking into account the second component, the mass of the system should be around, at least, four solar masses. Orbital radius of such star should be about 33 astronomical units, the orbital length then should exceed two hundred astronomical units."

While researchers see a total eclipse at present, they are not sure of the reasons behind it.

The study was published in the March 2016 issue of the journal Astronomy & Astrophysics.