University of Washington astronomers were on the lookout for “stars behaving strangely” when an automated alert from pointed them to Gaia17bpp, a star that had gradually brightened over a 2 1/2-year period. But follow-up analyses indicated that Gaia17bpp wasn’t changing. Instead, the star is likely part of a rare type of binary system. Its apparent brightening was the end of a years-long eclipse by an unusual, “dusty” stellar companion.
Astronomers have long suspected that superflares, extreme radiation bursts from stars, can cause lasting damage to the atmospheres — and thus habitability — of exoplanets. A new study published in the Monthly Notices of the Royal Astronomical Society reports that they pose only a limited danger to planetary systems.
Astronomers have catalogued 126 years of changes to a binary star system called HS Hydrae. Analyzing observations from astro-photographic plates in the late 1800s to TESS observations in 2019, they show that the two stars in HS Hydrae began to eclipse each other starting around a century ago, peaking in the 1960s. The degree of eclipsing then plummeted over the course of just a half century, and will cease around February 2021.
UW astronomers Brett Morris and James Davenport assisted in new research on “Tabby’s Star,” named for Louisiana State University astronomer Tabetha Boyajian.