In 2015, a star called KIC 8462852 made a lot of noise in the astronomical community, bursting with a series of rapid, unexplained events, observed with the help of NASA’s Kepler (Kepler) space telescope. And since then the behavior of this star continues to remain a mystery to astronomers.
In a new study, astronomers Josh Simon and Benjamin Shappee of the Carnegie Institution of the United States, together with colleagues, studied the behavior of this star for a longer period of time, beginning in 2006 – that is, until the moment when The unusual behavior of this star was first discovered with the help of the Kepler observatory. Previously, astronomers believed that the brightness of this star only decreases with time, but this new study reveals a significant increase in the brightness of the star in 2007 and 2014. These unexpected episodes make the scientific explanation of the behavior of the mysterious star quite difficult.
Previously, Simon, along with colleagues, found that during the period from 2009 to 2012, the brightness of the star KIC 8462852 decreased by almost one percent. Then, the brightness fell sharply by an unusually large value of 2 percent for only 6 months and remained at this level during the last 6 months of observations with the help of the Kepler observatory.
In a new study, the researchers analyzed the behavior of this star over the past 11 years, using data obtained with sky surveys from the All Sky Automated Survey (ASAS) and the All-Sky Automated Survey for Supernovae (ASAS-SN). They found that the brightness of the star continued to fall from 2015, and now its magnitude is about 1.5 percent less, compared with February of that year. Moreover, the authors showed that, in addition to the periods of decline in the brightness of the star, which lasted from 2009 to 2013, and from 2015 to the present, there was also a temporary increase in the brightness of this star, which took place twice.
“The next important step in our study will be observations of the color change of this star over time, especially during periods of short-term reduction in its brightness,” Sheppy said. “This information should help us to find a logical explanation for the unusual behavior of this star.”
For example, if the decrease in brightness is due to a dust cloud passing in front of the star, it will become more red when the brightness decreases. However, if the light of a star blocks large dense objects, then color changes will not be observed.