In 2015, a star called KIC 8462852 made a big splash in the astronomical community with a series of fast-paced, unexplained events observed with NASA's Kepler Space Telescope. And since then, the behavior of this star has continued to remain a mystery to astronomers.
In the new study, astronomers Josh Simon and Benjamin Shappee of the Carnegie Institution, USA, together with colleagues studied the behavior of this star over a longer period of time, starting in 2006 - that is, until the moment when the unusual behavior of this star was first discovered by the Kepler Observatory. Astronomers previously believed that the star's brightness only decreased over time, but this new study reveals a significant increase in the star's brightness in 2007 and 2014. These unexpected episodes make it very difficult to scientifically explain the behavior of the mysterious star.
Earlier, Simon and his colleagues discovered that between 2009 and 2012, the brightness of the star KIC 8462852 decreased by almost one percent. The brightness then plummeted by an unusually high 2 percent in just 6 months and remained at that level for the last 6 months of Kepler observations.
In a new study, scientists analyzed the star's behavior over the past 11 years using data from the All Sky Automated Survey (ASAS) and All-Sky Automated Survey for Supernovae (ASAS-SN). They found that the star's brightness has continued to fall since 2015, and now its magnitude is about 1.5 percent less than in February of that year. Moreover, the authors showed that, in addition to the periods of decrease in the brightness of the star, which lasted from 2009 to 2013. and from 2015 to the present, there has also been a temporary increase in the brightness of this star, which has occurred twice.
“The next important step in our research will be to observe the color change of this star over time, especially during periods of short-term decrease in its brightness,” Sheppie said. "This information should help us find a logical explanation for this star's unusual behavior."
For example, if the decrease in brightness is due to a cloud of dust passing in front of a star, then it will turn redder as the brightness decreases. However, if the star's light is blocked by large, dense objects, then no color change will be observed.
The work appeared on the server of preliminary scientific publications arxiv.org.