Exploring Mysterious Stars in The Universe – Space Science Documentary

Exploring Mysterious Stars in The Universe - Space Science Documentary Listen

A livestream from Space Universe published in Space

In 2016 Tabetha Boyajian (Louisiana State University) and collaborators, including citizen scientists on the Planet Hunters website, announced the discovery of the “most mysterious star in the Galaxy.” Boyajian’s Star exhibited lots of strange behavior: In data collected by Kepler satellite, the star’s brightness appeared to dip in ways that were not easily explained. Some dips diminished the stars brightness by up to 22% for several days at a time, and they weren’t periodic or symmetric.
The discovery set off a flurry of investigations into the star. Scientists trawling through astronomical archives found that Boyajian’s star had dimmed over much longer timelines, slowly fading over the last century.
Yet despite its strange behavior, the star itself looked remarkably ordinary. It was a bit more massive than the Sun, a little younger, but the star showed no extra infrared radiation that would be expected if it hosted a large debris disk or planets. The spectrum also didn’t show any strange spectral lines that would have indicated material accreting onto the star (or being ejected from it).
So Boyajian and collaborators proposed an unlikely but not impossible scenario: that something had kicked large amounts of dust, potentially from swarms of comets, into orbit around the star. Other astronomers proposed that interstellar dust was obscuring our view of Boyajian’s star, while still others suggested the star had recently ingested a planet. Some astronomers even proposed that the star itself could be misbehaving.
One thing was clear: more data were necessary. Kepler’s steady gaze garnered incredibly detailed observations of the star over four years, but the spacecraft’s main mission had come to an end in 2013, before the discovery paper was even published. Ground-based observations since Kepler had glimpsed the star only on good behavior. Moreover, the dips that Kepler had caught provided limited information, since they were only observed at a single wavelength band.