Bright stars can be seen on a clear night across the world, but one star in the sky has been dimming.
Massimo Marengo, associate professor of physics and astronomy, recently conducted a study examining the dimming of star KIC 8462852.
In light of data from NASA’s Kepler spacecraft examined by Sarah Willis, former ISU graduate student who now works for the Massachusetts Institute of Technology’s Lincoln Laboratory, Marengo decided to delve further into the phenomena with Willis and Alan Hulsebus, graduate assistant in physics and astronomy.
Their study was published in the Astrophysical Journal Letters and was even mentioned on NASA's website.
Marengo was drawn to the star after hearing about it in the news, where he recalls someone had the idea that the signature of the star was unusual enough to be an indication of an unorthodox phenomenon.
“A former student of mine that is now at MIT Lincoln Laboratory had the idea of checking if the data not used in the analysis was available,” Marengo said.
Willis found that there was in fact public data from NASA's Spitzer Space Telescope. Through checking if there was any emission at different wavelengths and dates after the events Kepler observed, they were able to add to the study of the star.
Data from the telescope revealed that a star was dimming up to 20 percent, something that normally doesn’t happen.
“Kepler is so precise it can measure changes in the brightness of a star by [a] part per million and this was 20 percent part in five,” Marengo said.
Looking through Kepler’s archives, Marengo couldn’t find evidence of any other stars dimming this significantly.
“In a sense, this phenomenon from an observational point of view is unique," Marengo said.
They confirmed that after the unknown events that happened to the star, the star didn’t show any infrared excess.
An analysis of infrared light was vital to the study because it helped discover the origin of the events that happened. Since there was no excess of infrared light detected through Spitzer, the likelihood of comets being the reason for the dimming was heightened, according to their study.
“The scenario invoking the fragmentation of a family of comets on a highly elliptical orbit is ... consistent with the lack of strong infrared excess found by our analysis,” the group reported in its study published in the Astrophysical Journal.
The study done by Marengo, Willis and Hulsebus was completed within a week. However, Marengo says that more data needs to be collected in order to fully prove that a comet was responsible for this unusual phenomenon. But the star's commonality is what keeps him interested in this case.
"The star itself is a perfectly normal star, which makes it more surprising," Marengo said.