Huge and opaque 'something' dims a giant star - EarthSky

Tabby’s Star was dimming rapidly, in weird and unexpected ways.

It’s a huge and opaque “something” that dimmed the brightness of a giant star by up to 97% over a period of about 200 days.

Even the largest dips in the brightness of Tabby’s Star reached only about 22%.

The star, VVV-WIT-08, is an evolved giant star, some 100 times larger than our sun.

With Tabby’s Star, for example, the dimming differed with different wavelengths, which is compatible with clouds of dust.

But with VVV-WIT-08, the consistent dimming across all wavelengths shows that the object was much more opaque and “solid.”?

It might be orbiting the star.

Maybe the dimming of VVV-WIT-08 was caused by a debris disk.

Maybe the disk wasn’t orbiting VVV-WIT-08 itself, but another body that in turn is orbiting VVV-WIT-08.

In other words, maybe VVV-WIT-08 has a companion star or planet with a large, dusty debris disk.

The star was seemingly blotted out by one large continuous mass.

But those kinds of disks don’t fit with what’s been observed at VVV-WIT-08.

The researchers considered an orbiting body that is stripping dust off of VVV-WIT-08.

Another, more exotic possibility is that the orbiting body is a black hole with a dense debris ring around it.

Debris disks around main sequence stars are too optically thin.

While white dwarf debris disks are optically thick, they are too small.

These stars have been observed to be eclipsed by huge disks of dust, although not exactly the same as VVV-WIT-08.

The orbital period for whatever blotted out VVV-WIT-08 is still unknown, but must be at minimum 9 years, since another dimming episode hasn’t been seen yet since 2012.

There are certainly more to be found, but the challenge now is in figuring out what the hidden companions are, and how they came to be surrounded by discs, despite orbiting so far from the giant star.

Of course, speculation also includes the possibility of this being an artificial object or objects orbiting the star.

That would require solar power collectors in space, likely in a shell around our star, or around our planet

Proving the existence of an artificial structure in the vicinity of a distant star would be monumental

Bottom line: Something huge and completely opaque blotted out the giant star VVV-WIT-08 for 200 days, with minimum light occurring in April 2012

Source: VVV-WIT-08: the giant star that blinked