Gabby's Star
While the universe is vast, there is one star that has captured the attention of physicist and sci fi junkies alike. Tabby's Star, KIC 8462852, is projecting light in a way that has never been observed in the universe, leading some to speculate that the source is an advanced civilization that is building a super-structure around the star to utilize the full energy of the star.
It all starts in 1890 when the first light observations were made of the star. The way astronomers study stars is by the luminosity of the light emitted and the pattern that light follows over time. When a star's light dims, it usually indicates the presence of matter that is absorbing the light. For example, when Jupiter crosses our sun, its mass results in reducing the luminescence of our star by 1%.
What is so unusual about Gabby, is that the star has fluctuating by as much as 20% and is doing so in a sporadic and irregular pattern. Observed by NASA's Kepler telescope, Gabby has dimmed by 15% and then again 22% roughly 750 days apart, indicating a significant obstruction. In addition, historical data suggest that the star is become less luminescent over time.
What could be the possible explanations?
It's just a natural star feature
In the 150,000 stars that Kepler has studied, this is the only star exhibiting this behavior. In such a vast universe, it is unlikely to be unique natural processes.
It's a planet blocking the light
The Kepler mission found that the drop in light was slow, indicating that the alleged planet would have to be moving very slow. Likewise, the amount of mass needed to produce a 22% decrease in luminosity is more mass than exists in our solar system. In fact, the mass needed would be a large fraction of the sun's mass. It is doubtful the source could be a large planet.
It's a comet field or gas cloud
Like the planet analogue, there simply cannot be enough mass to bend that much light. Also, such a structure would glow infrared and be observed by by NASA telescopes. Such a glow has never been observed. So, this theory has been ruled out.
It's a Dyson Sphere
Could the interference actually be a super-structure being built around the star. A Dyson sphere ( Wikipedia link ) fits such a possibility. It is theorized that such an advanced culture could have built self-replicating energy converters that harness the sun's energy directly into matter, using the sun's own solar emission to grow a giant sphere around the star. The structure would maximize either energy production or food growing cycles.
Such technology may be Star Trek science, but we all carry along a tricorder (cell phone) with us now. Time will tell.