Stars, beautiful burning celestial objects. Our universe –as far as we know- is ever-expanding. There are many millions to billions of galaxies spread across in this vast cosmic ocean. Many may be dead; many may be forming as we speak. Our galaxy is just one speck in this massive cluster. Just a drop in this ocean.
It is estimated that there are about 100 billion stars in our Milky Way galaxy alone. And, it is roughly estimated that there are about 10 trillion galaxies (10,000,000,000,000) in the observable universe. Even if we consider the average number of stars in the galaxy with ours, there would be approximately 1,000,000,000,000,000,000,000,000 stars, or a “1” with 24 zeros after it (1 septillion in the American numbering system; 1 quadrillion in the European system).
In the year 2015, an American astronomer Tabetha S. Boyajian announced a star with irregular light fluctuations. At a distance of 1,470 light-years in the Cygnus constellation, there lies a star which confused astronomers for years and whose mystery is yet to be solved. KIC 8462852 or commonly known as Tabby’s star or Boyajian’s Star WTF Star has shown an incredible 22%; dip) dimming in brightness). Hold on to that name. Before we see what’s wrong with the star, let’s see how they observe the drip.
Astronomers use a method to detect planets around another star. It is known as the transit method. The name itself says it all. When an object passes in front of a star, it covers/ blocks some light in a particular region while it is passing by the star. By the amount of light blocked and the intervals of the dips tells us weather a planet is present in that star system or not.
Hard to imagine? Try this; sit in a room where you can see the light source (like bulb or tube or fire). Sit/Stand(whichever is comfortable) at a distance from that source(make sure it is in your line of sight). Now, try blocking the light by placing your palm in front of your eyes(at a distance). Try to experiment with different objects, like a ball or a pen or anything you like(even a table if you can hold it). Observe the shape of light around that object and the area of light it blocks. Just maximize this experiment to a larger scale and you’ll able to link.
When the dips are of regular intervals and have the same percentage of dimness for a period, depending upon the dimness, we can say that there is a planet in that star system (exo-planet).
So now WTF star, I mean, where’s the flux star- literally, we can’t find enough flux (apparent brightness of a star) for this star. In general, most planets cause a dip <1% but this star was showing irregular dips to max up to 22%. It fades over for decades but with occasional brightening events, the overall brightness fluctuates irregularly with no infrared emission (other huge stars with large flux dips possess the infrared emission). Tabby’s star is an F-type main-sequence star i.e. this star has a mass ranging from 1.0 to 1.4 solar masses.
As far as we know, no planet can cause that kind of dip, not even the J1407b which is commonly referred to as super Saturn which has a radius of 90 million kilometres-it’s like steroids on Saturn. We can imagine the star having a protoplanetary disk around it, but Nah, its many hundreds of millions of years too old to have it and many stars with protoplanetary disk emit infrared flux; considering this factor, the Tabby’s star doesn’t emit it (and hence WTF-where’s the flux). A protoplanetary disk is a rotating circumstellar disc of dense gas and dust surrounding a young newly formed star.
What could be the reason behind these dips? As seen, Tabby’s star dip varies anywhere from <1% to 22%. Something which is massive, more massive than a planet can cause that dip. Many hypotheses are roaming around what caused the dip. One of them being, is a series of a comet passing in front of the star. But a huge stream of comets with varying sizes should pass on for hundreds of years to cause that dip. What other possible explanation might suites this star? How about an alien megastructure?
Dyson sphere is a concept proposed by Freeman Dyson. Dyson sphere was a thought experiment of Freeman Dyson of an advanced alien civilization using a mega structure to absorb the energy of a star. This free-floating structure comes in various formats; one being a series of drones or structures orbiting the star to collect the energy or a superstructure which covers the whole star while revolving around it. This could explain the irregular dips of the Tabby’s star; this is like a perfect piece of the puzzle to explain what’s going on with Tabby’s star. So is this an alien structure?
1,470 light-years- that’s pretty close to earth (but still far). But an advanced civilization with that kind of technology might be able to reach here within a very short period. Are they collecting energy from the Tabby’s star? Did they hear our signal? Are they on their way to earth? How will they see us if they reach earth? Masters or slaves? Friends or foes? Will they coexist with us? Or will they wipe out our civilization and exists?
Nope! Sorry to disappoint you, but the answers to the above question is a no (could be a yes, but no (Schrodinger’s yesno).
Recent observations and studies of the Tabby’s star have found a weird but interesting hypothesis. What if Tabby’s star stole a moon from another planet? An exomoon. When a planet in that star system went rouge and lost orbit, there is a chance its moon lost its way and is falling towards the star. And due to its (tabby’s star) pull, the atmosphere of the moon is being ripped away piece by piece. The closer it gets to the star, the larger the chunks get. This is the best possible theory for now. No conclusions can further be drawn about this star until we have more observations to take and more pieces to solve this puzzle.
Dyson sphere? Alien megastructure? It may not be the case with the Tabby’s star but I’ll leave this question to your imagination. Consider the numbers mentioned in the first paragraph again. Now, don’t you think they exist? If they do, where are they? Why didn’t we see them yet? Are they like humans or like any other being or earth? How do they look? Did we find any alien? How do they think? What do they breathe? Most importantly, will they see humans as friends?