A computer system model of VVV-WIT-08, showing the star, a mystery disk passing in front of it and a smaller item inside the disk. The star, VVV-WIT-08, is a progressed giant star, some 100 times bigger than our sun. Main series stars, like our sun, and white dwarf stars have actually been know to have debris disks. The dust around Tabbys Star is not almost as nontransparent as whatever blotted out this other huge star. Accretion disks around black holes and neutron stars usually emit X-rays, however a black hole alternative disk of the type described by Perna et al. (2014) might plausibly explain the occultation.

A computer design of VVV-WIT-08, revealing the star, a mystery disk passing in front of it and a smaller sized things inside the disk. Image through Leigh Smith/ YouTube.
Keep in mind Tabbys Star? Citizen researchers with the Planet Hunters task identified it in 2015. Tabbys Star was dimming quickly, in unforeseen and weird methods. The theories for its uncommon habits ranged from alien megastructures to clouds of dust. That mystery hasnt been totally solved, but dust does now appear to be the culprit. In June 2021, astronomers launched a brand-new research study about a new and even bigger mystery (actually). Its a substantial and nontransparent “something” that dimmed the brightness of a giant star by as much as 97% over a duration of about 200 days. Even the biggest dips in the brightness of Tabbys Star reached only about 22%. Is it dust again? What else could it be?
The star, VVV-WIT-08, is an evolved huge star, some 100 times bigger than our sun. Its older than our sun, too, about 8 billion years of ages in contrast to our suns 4 1/2 billion years. It lies roughly 25,000 light-years away in the instructions of the constellation Sagittarius, towards the thick center of our Milky Way galaxy.
Its minimum brightness took place in April 2012. Scientists still do not have an explanation.
But theyre still considering it. The journal Monthly Notices of the Royal Astronomical Society published a brand-new study about this star on June 11, 2021. See the preprint here.
Something dims a giant star
Its a fascinating mystery, because whatever blotted out the star does not seem to have the properties of a normal dust cloud. As explained in the brand-new paper, whatever it was had a “difficult edge” and was practically entirely opaque.
Astronomers initially noticed the weird event in data from the VISTA Variables in the Via Lactea (VVV) study. As lead author Leigh Smith of the University of Cambridge told The Guardian on June 11:
It appeared to come out of nowhere.
He likewise informed National Geographic six days later on:
Its unusual for a star to dim in brightness by this much and for this long.
Another group member, Sergey Koposov of the University of Edinburgh, commented in the scientists statement that:
Its amazing that we just observed a dark, large and elongated item pass between us and the distant star, and we can just hypothesize what its origin is.
Astronomer Leigh Smith at the University of Cambridge led the new research study on the strange dimming of giant star VVV-WIT-08. Image via LinkedIn.
Image sequence showing the star at regular brightness in 2010, then dimmed up to 97% in 2012, and after that back to regular brightness in 2013. Image through ESO/ The Guardian.
They saw it happen just once
Seeing such a remarkable dimming, with such a mystical and unknown cause, is both interesting and frustrating for astronomers. They see that the drop in brightness is excellent: 97%! And they d like to have the ability to puzzle out how such a significant brightness drop might take location. These astronomers utilized information from the European Space Agencys Gaia spacecraft and the ground-based study called OGLE to attempt to solve the mystery.
However there are many, numerous possible circumstances suggested by the data. With Tabbys Star, for instance, the dimming differed with different wavelengths, which is suitable with clouds of dust. However with VVV-WIT-08, the constant dimming throughout all wavelengths shows that the item was much more nontransparent and “strong.”.
Another curiosity was that the observations from Gaia even suggested that the star was moving through area much faster than formerly believed, almost quickly sufficient to leave the Milky Way.
That doesnt make sense for a star situated in the instructions of the galactic bulge, in the middle of our galaxy.
Lots of theories, but no answers.
Astronomers said that– to try to describe the strange event– theyve thought about and then declined lots of possible theories. The object appeared to be bigger than the star itself, however could it have been smaller than thought and closer to Earth? Might it have wandered in front of the star, from our viewpoint, by opportunity?
If it occurred for this star, should not it occur for others? That would suggest there need to be numerous dark, floating things in the space of our galaxy.
Could the dimming have rather originated from the star itself? Stars that dim and then get intense again are common. However giant stars like VVV-WIT-08 dont tend to drop in brightness by 97%. As noted in the paper:.
The habits of the light curve of VVV-WIT-08 does not correspond to any known intrinsic outstanding irregularity. It is likely an occultation of the huge star.
Now, the most plausible conventional explanation for VVV-WIT-08 would be a giant debris disk of dust and small rocks that orbits a still-unknown body that, in turn, orbits the star. Image via NASA/ JPL-Caltech/ Jacob White.
Could it be a debris disk?
The scientists say the item that caused the dimming is probably gravitionally bound to the star. It may be orbiting the star. What is it?
They in some cases surround stars, the method that rings surround a world like Saturn. Perhaps the disk wasnt orbiting VVV-WIT-08 itself, however another body that in turn is orbiting VVV-WIT-08. In other words, perhaps VVV-WIT-08 has a companion star or planet with a large, dirty debris disk.
Dust is typically easily identifiable, however, as it filters light in such a way that permits longer, redder wavelengths to go through it. The information from VVV-WIT-08 didnt look like that.
Particles disks likewise dont have “tough edges”. With dust, you normally see a tapering off at the edges.
Another possibility though is a huge ring system around the orbiting body. Astronomer Jason Wright at Pennsylvania State University noted in National Geographic that Saturns rings have distinct edges. That meaning is thanks in part to the gravitational influence of little moonlets that orbit in the spaces between the rings.
This things would likely need to be one giant ring though, since no gaps were observed. The star was seemingly blotted out by one big constant mass.
If its a debris disk, then whats it orbiting?
Possibly the things hiding the star is a debris disk. If so, we still dont understand what the debris disk is orbiting. Main series stars, like our sun, and white dwarf stars have actually been know to have debris disks. Those kinds of disks dont fit with whats been observed at VVV-WIT-08.
Or, heres another dust scenario that does not fully in shape, but is still on the table. The researchers thought about an orbiting body that is stripping dust off of VVV-WIT-08.
The strange dimming of VVV-WIT-08 is reminiscent of Tabbys Star in some methods (artists concept). However the dust around Tabbys Star is not nearly as opaque as whatever blotted out this other huge star. Image via NASA/ JPL-Caltech/ Sky & & Telescope.
Could it be a great void?
Another, more unique possibility is that the orbiting body is a black hole with a thick particles ring around it. Appealing, although its something that hasnt been seen before. From the paper:.
Debris disks around primary sequence stars are too optically thin. Accretion disks around black holes and neutron stars normally give off X-rays, but a black hole fallback disk of the type explained by Perna et al. (2014) might plausibly discuss the occultation.
Blinking giant stars.
Astronomers also believe its possible that VVV-WIT-08 might come from a new class of “blinking giant” stars.
These stars have actually been observed to be eclipsed by big disks of dust, although not precisely the very same as VVV-WIT-08. Another giant star, TYC 2505-672-1, is eclipsed every 69 years.
Philip Lucas from the University of Hertfordshire said in the declaration from University of Cambridge:.
, or WIT items. We actually dont know how these blinking giants came to be.
Huge stars typically launch material into area, but its the specific nature of the product near VVV-WIT-08 that has astronomers so puzzled. As Levesque told National Geographic:.
Its well not too bizarre; its the sort of thing that you would anticipate. But dust does not look this neat, and it would certainly suggest something extremely uncommon about how that dust is dispersed.
If these undoubtedly are a brand-new kind of “blinking huge” stars, then astronomers expect to discover more of them, according to Smith:.
There are definitely more to be discovered, but the obstacle now remains in determining what the covert buddies are, and how they happened surrounded by discs, despite orbiting up until now from the giant star. In doing so, we may learn something brand-new about how these sort of systems progress.
Last, but not least, could it be artificial?
Naturally, speculation also includes the possibility of this being a synthetic object or items orbiting the star. Dyson spheres enter your mind. Supporters of solar power know that just a tiny portion of the suns overall energy strikes the Earth. What if we, as a civilization, could collect all of the suns energy? That would need solar power collectors in space, likely in a shell around our star, or around our world.
If we constructed such a thing, we would be using some kind of Dyson sphere, in some cases described as a Dyson shell or megastructure.
Showing the presence of an artificial structure in the vicinity of a far-off star would be monumental. It would mean there are sophisticated civilizations somewhere else in our galaxy.
However, as always, astronomers will tell you we should not leap to this conclusion, every time we discover something strange.
Therefore the search for answers continues!
The most interesting possibility for VVV-WIT-08 would be something artificial orbiting the star, something like a Dyson sphere (artists principle). But whatever caused the dimming seems to be orbiting the star, not surrounding it as a Dyson sphere would. Image by means of CapnHack/ energyphysics.wikispaces.com.
Bottom line: Something big and completely opaque blotted out the giant star VVV-WIT-08 for 200 days, with minimum light taking place in April 2012. Researchers still do not understand for sure what it was. A new study raises more concerns than responses.
Source: VVV-WIT-08: the giant star that blinked.
Via University of Cambridge.
Via The Guardian.
Via National Geographic.