Scientists at Lomonosov Moscow State University, with the help of a global network of robotelescopes, have discovered a star that's a bit more unusual than most. This bright star has faded significantly, which raises questions about whether it was a binary star, or if it just faded naturally.
The network of telescopes, known as the MASTER network, was created for the purpose of detecting gamma-ray bursts, which are the most energetic flashes in the universe. In this case, though, the researchers used MASTER to look at something else.
Three years ago, astronomers working with MASTER noticed a giant bright star that was named TYC 2505-672-1, which had faded to the point where its brightness decreased nearly 100 times.
At first, the researchers didn't think that the star's fading was all that significant, as things like this happen sometimes in the universe. However, the researchers couldn't figure out how the star became so dim. One theory proposed that a red giant emitted a cloud of stardust made of carbon particles that "hid" it from view.
With that said, the new measurements showed that the star didn't turn red. Because of this, the researchers looked a bit more closely at the star to figure out exactly what happened.
In this case, the researchers found that the star became a record-breaker in a length of variation period, which lasted about 69 years. The longest known variation period previously belonged to Epsilon Aurigae, whose eclipses repeat in a bit more than 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."
The findings reveal a bit more about this system, but they also raise questions. Currently, the researchers see a total eclipse, but they are still unsure as to what exactly causes this eclipse.
The study was published in the March 2016 issue of the journal Astronomy & Astrophysics,
