Back in 2012, a mystery object blocked most of the slight from a distant star in our galaxy named VVV-WIT-08. The star was dim for around 200 days before becoming fully visible again. The weird phenomenon hasn't been observed since. What caused this strange vanishing act? Astronomers are exploring a few possibilities but haven't found a real answer. Nadia Drake writes in National Geographic:
Described in a new study in the Monthly Notices of the Royal Astronomical Society, some of the theories still on the table rely on as-yet unobserved phenomena, such as a dark disk of material orbiting a nearby black hole, or undiscovered, dust-enshrouded companion stars.[…]
It's clear that whatever object eclipsed the distant star is huge—much bigger than the star itself. It also appeared to be completely opaque, blocking much of the starlight entirely, and it seemed to have a hard edge[…]
And while it might be tempting to wonder whether some type of extraterrestrial megastructure could have flown in front of the star, Wright says that hypothesis isn't ripe for serious consideration yet.
"It's premature at this point," he says. "There's so much about this star that we don't know."
"Mystery object blotted out a giant star for 200 days" (National Geographic)
Image: "Artist's impression of the binary star VVV-WIT-08"/Amanda Smith (University of Cambridge)