Star dimming due to Alien Megastructure or natural forces?

Tabetha Boyajian, a researcher at Louisiana State University published a paper entitled “Where’s the flux?” This paper had the effect of putting the weight of her doctorate degree in astrophysics behind the findings made by citizen scientists working on the Planet Hunters project. Planet Hunters allows people to help look for spectral anomalies and periodic dimming caused by planets passing in front of their host star.

The data analyzed is from light collected by the Kepler Space Telescope, a half-a-billion dollar infrared detector parked into its own orbit around the sun. This modern technological marvel collected tons of valuable data from 2009 till 2016, at which time it stopped being useful to scientists because too many of its mission-critical systems had deteriorated.

Kepler collected light from over 150,000 stars before expiring, this was so much data that researchers were unable to process all of it, that’s when the internet community stepped in via the Planet Hunters project. On their website they allow anyone to access the data collected by Kepler, and flag irregularities in the star’s brightness which could be the shadows cast by planetary transits.

It was through this global community outreach, that a startling discovery was made about an unassuming star in the Cygnus constellation. The dramatic dimming of KIC 8462852, which has since been nicknamed “Tabby’s Star” or “Boyajian’s Star,” was unlike anything is ever seen before. Some of these events caused Tabby’s star to reduce its brightness by 22%. No other star observed by Kepler dims this much.

Tabby’s Star is a Type-F main-sequence star, which is also called a yellow-white dwarf. It lies 1280 light years from Earth and has a mass of about 1.43 times that of our sun. The star that grants our beautiful blue world light and warmth, is a Type-G yellow dwarf, which makes it a little smaller and a little cooler than Tabby’s star.

Once the findings were made public, the best and brightest minds all over the world began to concoct possible explanations for the unusual behavior. In Boyajian’s paper, she runs through all the usual suspects of what was causing the peculiar observations. An asteroid belt, dust, malfunctions with the Kepler Space Telescope, each one of these plausible possibilities didn’t quite explain all of the strange patterns of irregular periodic dimming.

Enter Jason Wright, an astronomer from Penn State University. In an interview with The Atlantic he told reporters, “When [Boyajian] showed me the data, I was fascinated by how crazy it looked. Aliens should always be the very last hypothesis you consider, but this looked like something you would expect an alien civilization to build.” Of all the possibilities, something like a Dyson’s Sphere was the most sensational and made headlines across all major media.

A Dyson’s Sphere is a theoretical megastructure first described by science fiction writer Olaf Stapledon, in his 1937 novel Star Maker.

“Not only was every solar system now surrounded by a gauze of light traps, which focused the escaping solar energy for intelligent use, so that the whole galaxy was dimmed, but many stars that were not suited to be suns were disintegrated, and rifled of their prodigious stores of sub-atomic energy.”  

Stapledon’s graphic depiction of what an advanced civilization might look like was referenced in 1960 by theoretical physicist Freeman Dyson in his paper “Search for Artificial Stellar Sources of Infrared Radiation.” Dyson, like Stapledon realized that technological progress would require ever increasing amounts of energy, eventually surpassing that which could be produced by resources found on rocky planets. The concept of a Dyson’s Sphere has since been expanded into many different possible versions besides a complete sphere, solar energy collectors may look more like bands, rings, bubbles or a swarm orbiting a star.

A Russian astrophysicist Nikolai Kardashev also came to this same conclusion in 1964, even though he was separated by the iron curtain of the cold war. He created what would be known as the Kardashev scale, this scale is divided into three types.

Type 1: Planetary Civilization – Being able to harness all the power generated from planetary resources, such as: fossil fuels, the energy of falling water, wind, waves/tides and atomic fission. Humans are still decades from reaching Type 1

Type 2: Stellar Civilization – Harnessing all the power emitted by the star that illuminates the species host planet

Type 3: Galactic Civilization – Controlling all of the energy of the entire galaxy

Kardashev believed it was possible that there may be intelligent life millions or billions of years ahead of earthlings in terms of technology. Furthermore, he stressed that intelligent life that far beyond us, maybe so powerful and different as to be completely unrecognizable by us at our current stage. Type 2 and 3 beings maybe completely invisible to us, walking through walls unnoticed or controlling the rotation of the earth and moon without us ever knowing. Maybe even creating a computer so powerful as to simulate the entire cosmos that we call home. The theories about possible technological paths are endless, with some postulating that certain species of mushrooms could be a form of technology as it is believed the spores can survive interstellar transit.

With all of these ideas in mind and loads of excitement, astronomers pointed radio telescopes towards the most interesting star in the galaxy. Unfortunately, they didn’t pick up reruns of the alien equivalent to The Price is Right, but they were not dissuaded. Scientists looked through more than a century of records hoping to find clues. They discovered that the star has been dimming overall and that the more intense periodic dimming occurs on 800 and 1,500-day cycles.

Boyajian started a Kickstarter campaign to raise $100,000 in order to conduct more research, she wanted to catch the star dimming in real-time. In May of 2017 she struck gold, the star began to dim and astronomers throughout the northern hemisphere fixed their gaze upon it, collecting data across the entire light spectrum. They witnessed four distinct dips which were named Elsie, Celeste, Scara Brae, and Angkor. “It was kind of surreal in a way to watch it happen in real time and be able to do what we have been saying we wanted to do for years: observe it in a dip,” she told National Geographic.

The fruits of Boyajian’s obsession yielded fascinating results. She doesn’t believe it is evidence of a Dyson’s Sphere, because the light isn’t being filtered out evenly. “If a solid, opaque object like a megastructure was passing in front of the star, it would block out light equally at all colors. This is contrary to what we observe,” she told National Geographic.

Many of the best and brightest minds now believe dust is to blame, but there are still a lot of unexplained observations that bring the dust hypothesis into question. Chief among these unanswered findings is that the dips in light output vary in their intensity and timing, not what you would expect if the dust cloud was orbiting around the star in a smooth and regular manner. Furthermore, the dust isn’t emitting infrared light, meaning it is cold and far from the star. Also, the dust grains are really small, smaller than cigarette smoke, the solar wind of Tabby’s Star should have blown them away long ago, leading some to theorize that the dust is being replenished somehow.

With these unanswered questions, more theories have emerged. Brian Metzger an astrophysicist at Columbia University published a paper postulating that Tabby’s Star tore apart a rocky planet that had the bad luck of drifting too close, leaving a dust-spewing corpse that orbits far from its assailant. He also puts forth the idea that the odd dimming is caused by a large group of comets similar to those that make up the Kuiper Belt and Ort Cloud in our solar system, and that they were pulled into this irregular orbit by a neighboring red dwarf.

Megastructures built by a super civilization seem like they could still be a possibility given all the unexplainable observations made by the most sophisticated technology currently available. We would be foolish to believe that we would know exactly what a Type 2/3 civilization would look like.