Reconstruction of KIC 8462852 showing what an alien megastructure
might look like (pic credit: Andrew Collins).


(with Sept 2016 update below)

Andrew Collins

In mid October 2015 scientists announced that "alien megastructures" might have been detected orbiting a distant star in the Cygnus constellation. Although this announcement, coming from leading researchers in the field of space science, might yet prove to have been premature, the long term effects of this statement could have profound implications for humanity's attitude towards intelligent life existing in the universe. Beyond this is the tantalising possibility that what has been found some 1,480 light years from earth really does constitute the first hard evidence for the existence of sophisticated alien technology. Under this presumption, might we ask what an alien megastructure actually looks like? What its function might be, and what kind of life form could have been responsible for its creation? All these questions will be answered, but first some background to the discovery.

In 2009 NASA launched the Kepler Space Telescope. It main purpose was to search for rocky worlds not unlike our own within an area of the night sky embracing the constellations of Cygnus and Lyra. So far over a thousand exoplanets have been identified, and many more will be found in the coming years.

Yet Kepler is looking for far more than simply earth-like planets. It can record stellar flares, star spots and dusty planetary rings, and in 2011 it began sending back data regarding a curious star located in the heart of the Cygnus constellation. It seemed so strange, so unusual, that any knowledge of its existence was withheld for four years so that it might be better understood. Only then did the researchers feel right about making an appropriate announcement, which came on October 14, 2015 - the upshot being that the star, known as KIC 8462852, might well be surrounded by an alien megastructure. Let me explain.


Starlight Dip

An exoplanet orbiting a distant star will periodically darken the stellar light emitted by its home star as it transits, or moves across, its face. When Kepler detects an exoplanet, it does so by sensing this very slight dip in starlight. This light curve, as it is known, becomes the exoplanet's signature, providing researchers with information about its physical size and even its global temperature and atmospheric composition. It also reveals its shape, which, as you might expect, is generally round in appearance. However, what crossed in front of KIC 8462852 in 2011 returned a highly unusual signature, implying that something of highly irregular shape was transiting the star, causing its starlight to dip intermittently.

According to a paper submitted to the journal Monthly Notices of the Royal Astronomical Society two highly significant light curves have been recorded in connection with KIC 8462852. The first occurred between days 788 and 795 of the Kepler mission, with the second coming between days 1510 to 1570 (Boyajian, 2015), that is in early 2013. The scientists involved in the mission refer to these transits as D800 and D1500 respectively. The D800 transit caused the starlight to dip by 15 percent, while D1500 consisted of a burst of transits, indicating the passage of an entire array of objects, causing the star to dim by a staggering 22 percent. To put this into perspective, when Jupiter, the largest planet in our solar system, crosses the path of the sun it dims its light output by no more than 1 percent. So whatever is transiting KIC 8462852 has to be seriously huge.
Potential Explanations

The above-cited paper, whose lead author is Tabetha S. Boyajian, a postdoctoral Fellow at Yale University and the discoverer of KIC 8462852, attempts to evaluate the data and offer some potential explanations. One is that the strange light curves are the result of disintegrating comets orbiting the star (Boyajian, 2015). However, this seems unlikely considering the enormous dips in the light curves, which would necessitate a whole swarm of comets entering into a tight orbit around the star (Plait, 2015). Also considered is the possibility that the dips are caused by a cluster of ringed planets, or perhaps a ring of asteroids orbiting the star following a planetary collision. Both solutions are seen as unlikely.

Astronomer Jason Wright of Penn State University, who was consulted by Boyajian, has proposed that the star's bizarre light dips are evidence perhaps that the star is much younger than previously thought, and that orbiting it is planetary material still coalescing (Wright, 2015). Yet this seems unlikely as KIC 8462852 has been firmly identified as a mature F-type main-sequence star some 1.5 times the size of our sun.

Wright, realising the failings of all these potential explanations, offers one further solution to this mystery, and this is the big one. The swarms of objects transiting KIC 8462852 - or Tabby's Star as it is called after its discoverer - might be "alien megastructures" used to collect starlight emitted by the star.


Freeman Dyson

Such megastructures have been the subject of science-fiction since the 1930s. They feature, for instance, in Star Maker, a 1937 novel by British sci-fi writer and philosopher Olaf Stapledon (Stapledon, 1937). However, it was only in 1960 that theoretical physicist and mathematician Freeman Dyson (b. 1923) began discussing the topic as a hypothetical reality. Following what he called a "thought experiment" he wrote that as an alien civilization advances it will eventually exceed the levels of energy offered by its home planet. This would move it eventually to create a technology whereby stellar light could be harnessed directly from a star.

More pertinent to this debate is the fact that Dyson proposed searching the skies for evidence of infrared radiation emitted by hypothetical megastructures constructed to harness such high levels of energy. This exercise, he predicted, could lead to the first detection of intelligent life in the cosmos (Dyson, 1960). Amazingly, that quite incredible prediction might just have been realised with the discovery of KIC 8462852.

Since Dyson originally conceived of the existence of stellar light collectors others have developed his ideas into workable models. For instance, the most popular form of megastructure conceived of by theoretical scientists is the Dyson sphere (Dyson has repeatedly proposed that it should be called a Stapledon sphere after Olaf Stapledon). This would completely encase a star absorbing all its starlight. Another form of megastructure known as a Dyson swarm would consist of entire arrays of much smaller structures that would either form rings or, as in the case of KIC 8462852, large clusters around the star in question.

There is, however, a problem in assuming that the swarm of objects orbiting KIC 8462852 is an alien megastructure. As Freeman Dyson deduced the high levels of energy absorbed by a stellar light collector would produce inordinate amounts of infrared radiation. Yet to date this has not been detected in connection with the star. Although unfortunate this changes nothing, for it could simply be that the alien megastructure, or structures, orbiting KIC 8462852 operate in a different way, leaving no obvious trace of infrared radiation.

Such was the situation when news of KIC 8462852's strange light curves was announced to the world back in October 2015. Press reports stated that the researchers involved were submitting a proposal to the SETI Institute in Berkeley, California, requesting that it turn one of the radio telescopes at its disposal towards KIC 8462852. It could then monitor the star system for evidence of intelligent radio signals.


Weird Periodic Signal

SETI were quick to take up the challenge. On October 16, just two days after the public announcement regarding the possible existence of the alien megastructures orbiting KIC 8462852, the Institute's Allen Telescope Array (ATA), composed of 42 telescopes located some 500 km north of San Francisco in the Cascade Mountains, was taken off its regular programme and directed instead towards the star (King, 2015). Within two weeks there were reports that the telescope array had detected a "weird periodic signal" coming from the star. In an interview with Dr. Gerald Harp from the SETI Institute stated that "although potentially [of] natural origin … there is clearly value to examine it more closely." He added that although a natural explanation was likely for the signal, he did not rule out the possibility that it came from "a distant intelligent source" (Adl-Tabatabai, 2015).

Clearly, this announcement, coming from a leading member of SETI, had those following this baffling mystery on the edge of their seats. Yet then came silence until, finally, on November 5 the Institute issued a press release announcing that it had failed to detect any radio signals coming from KIC 8462852 (Harp, 2015a). No radio transmissions of any kind could be found in either narrow band or wide band frequencies. Yet as Gerald Harp admitted: "Clearly, the energy demands for a detectable signal from KIC 8462852 are far higher than this terrestrial example (largely as a consequence of the distance of this star), meaning that there was no way of knowing whether our telescopes were attuned to quite the right frequencies"(Harp et al, 2015 b).

How exactly the earlier reports of a "weird periodic signal" detected coming from KIC 8462852 fit into this official announcement from SETI remains unclear. Either it was an artefact caused by terrestrial sources, or it was dismissed as unrepresentative of the results in general. Whatever the answer, SETI's findings helped dampen the initial sense of excitement regarding the nature of the strange light curves associated with KIC 8462852; the news story's honeymoon period was well and truly over.

So we will have to wait patiently before what could arguably be the greatest discovery of our time unfolds in full. Yet even if no useful answers are forthcoming in the coming years, there are far greater implications behind this incredible enigma. It embeds into people's minds the idea that today scientists can very easily conclude that unusual phenomena detected in deep space might be hard evidence of extraterrestrial life and even alien technology. Such announcements, coming from scientific institutions, increase, very subtly, the public's perception and acceptability of alien civilizations existing out there in the universe. It makes the whole subject that much easier to debate, as has been shown by the large number of news channels and radio shows that have openly discussed the reality or not of the proposed alien megastructures surrounding KIC 8462852.



This month a new paper from a German academic, Dr. Eduard Hendl, examines the unique periodic light dips recorded by the Kepler Space Telescope in 2011 and 2013 and concludes that they are the result of a process known as star lifting. This is the harvesting of stellar matter, most obvious hydrogen, helium or plasma, using an advanced form of alien technology. Star lifting can be utilised for a number of reasons, most obviously to harness a star's mass for use in construction or to reduce the light output or size of a star.

Are aliens harvesting the matter from weird star KIC 8462852. A German academic says yes! Pic credit: Andrew Collins

Star lifting is actually a smart solution to this mystery, much better than the existing proposal that any potential megastructure lurking around the star is either a starlight-collecting Dyson sphere or Dyson swarm (after the work of theoretical physicist and mathematician Freeman Dyson). Harvesting stellar matter in the manner described will actually cause a star's light flux to gradually dim in exactly the manner recorded in connection with Tabby's Star.

This long term light dimming was first noted earlier this year by Bradley Schaefer, professor of astronomy and astrophysics at Louisiana State University. He examined a set of old photographic plates - the so-called DASCH collection - housed today in Harvard University. They record every part of the night sky between 1890 and 1989. Examining the plates Schaefer found that KIC 8462852 had progressively dimmed its light by as much as 22 percent across the 100 year period the plates were being made. He published his findings online causing quite a stir in the process. However, his findings were called into question by a separate group of astronomers led by Michael Hippke, who found no such trend either in the Harvard plates or in another set from Germany known as the Sonneberg collection. Bradley Schaefer defended his position, leading to a rather public argument between all parties involved.

There the matter might have rested were it not for two astronomers, Carnegie's Josh Simon and Caltech's Ben Montet. They said, hang on, if this light dimming really was taking place across a period of 100 years shouldn't Kepler have seen this light dimming going on during the time it was observing the star between 2009 and 2013? Although the Kepler Space Telescope was created with this eventuality in mind - its main function being to register light flux perterbations caused by orbiting exoplanets - every month does capture the entire star field in view (this being the area between Cygnus and Lyra). What Simon and Montet found was that the Kepler data revealed that KIC 8462852 had dimmed by as much 3 percent in just five years of observation. So this new discovery suggests that Bradley Schaefer's findings were indeed correct. Thus it seems that since observations of the star began in 1890 it has lost a staggering 25 percent of its brightness, something that healthy F3 class stars just don't do! Arguably, this could have been going on for many years, perhaps even centuries, meaning that originally the star was might brighter indeed.

Star lifting can account for both the long term light dimming trends and the short term dips recorded by Kepler. These show a dramatic dip of up to 15 percent in March 2011 (known as D792, i.e. Kepler day 792) and another of up to 22 percent in February to April 2013 (known as D1519 and D1568). Other smaller dips of anything up to 3 to 5 percent also occurred at other times, and these too remain unexplained. Sadly, Kepler was not able to keep its focus on Tabby's Star after the dramatic dips of 2013, so we do not know whether any further light dips took place between then and October 2015. It was then that the star's strange activity was announced to the world, and since then every large telescope in the world has been pointing in the direction of Cygnus, without any further signs as yet of a major dip.

Heindl's working model for star lighting as the cause of the star's short term light dips (particularly light curve D792 that occurred in 2011) predicts that another large drop in light will occur in February-March 2017. Others, including Tabatha Boyajian herself, predict a major dip for May 2017. Let's hope either one of them is right.

None of this means that the mystery of Tabby's Star has been solved. Far from it. Plus there is every likelihood that a natural explanation will be found to explain all its anomalies reported to date, including both the short-term and long-term light dimming (even though aside from unlikely candidates like swarms of comets, disembodied planetary debris either around the star or in the nearby interstellar medium, and a disk of dust and cloud around an invisible black hole, natural explanations are sadly lacking at this time, and none proposed so far fully explain what is going on). Star lifting as a theory is a good one indeed. Only further data can truly help resolve this matter, and that we need urgently.

For those wishing to learn more about star lifting - its purposes and methods - watch this 30-minute Youtube video by science writer and futurist Isaac Arthur:

The concept with originally proposed by David R. Criswell, Director of the Institute for Space Systems Operations at the University of Houston, in his pioneering paper "Solar System Industrialization: Interstellar Migration and the Human Experience," published in Interstellar Migration and the Human Experience (Eds. B. R. Finney and E. M. Jones), 50-57, Uviv. Calif Press, 1986.
Dr Heindl's paper has been picked up by the media with the Daily Mail publishing a major feature online under the title: "Dyson sphere' star may be dimming because ALIENS are mining energy from its surface, claim scientists." It is a good account of what is going on up there, and also provides a full review of what we know so far about the mystery of Tabby's Star. Here is the link:


Engineer Rodney Hale and myself are also examining KIC 8462852's short term light curves in an attempt to imagine the object or objects that passed in front of the star in 2011 and again in 2013. The idea will be to recreate what they might have looked like to help astronomers better identify what is going on up there. This involves an extraordinary lot of technical work, which as a chartered engineer and keen astronomer Rodney is ideally placed to do. Preliminary results suggest we are dealing with something completely unique to astronomy. However, so as not to make any mistakes this process will proceed very slowly, with notes and observations being made every step of the way. We have been in communication with Dr Eduard Hendl about his own physical modelling of the light dips, and he has been helpful in providing us with his primary dataset for comparison with our own ongoing work.


Adl-Tabatabai, Sean (October 22, 2015), "SETI Receives First Alien Signal From Mysterious Star KIC 8462852", Your News Wire, The information from this source derived from an earlier German report from Grenzwissenschaft-Aktuell - see below.
Boyajian, T. S., D. M. LaCourse, S. A. Rappaport, D. Fabrycky, D. A. Fischer, et al. (11 September 2015). "Planet Hunters X. KIC 8462852 - Where's the Flux?". arXiv:1509.03622 [astro-ph.SR]. Submitted to Monthly Notices of the Royal Astronomical Society.
Collins, Andrew (2006), "Cosmic Rays and the Cygnus Mystery,",
Collins, Andrew (2012), LightQuest, Eagle Wing Books, Memphis, TN.
Freemann J. Dyson (1960). "Search for Artificial Stellar Sources of Infra-Red Radiation." Science 131 (3414): 1667-1668.
"Ferne Super-Zivilisation? SETI empfängt tatsächlich "sonderbare periodische Signale" von KIC 8462852," (October 22, 2015), Grenzwissenschaft-Aktuell,
Harp, Gerry (2015a), "Looking For Deliberate Radio Signals From KIC 8462852," (November 05 2015), SETI Institute,
Harp, Gerry (2015b), et al, "Radio SETI Observations of the Anomalous Star KIC 8462852" (November 5, 2015), PDF at
King, Bob (October 21, 2015), "SETI Institute Undertakes Search for Alien Signal from Kepler Star KIC 8462852", Universe Today,
Plait, Phil (14 October 2015). "Did Astronomers Find Evidence of an Alien Civilization? (Probably Not. But Still Cool.)". Slate. Retrieved 15 October 2015.
Stapledon, Olaf (1937), Star Maker, Methuen, London.
Wright, Jason (2015), "KIC 8462852: Where's the Flux?" (15 October 2015). AstroWright. Pennsylvania State University.

Many thanks to Richard Ward, Catherine Hale and Rodney Hale for their help with this article.



KIC 8462852 Update - September 2017

Is it a dead star walking?


Last October we brought you exclusive news of KIC 8462852 and its enigmatic light dimming by up to 22 percent, suggesting that something big and irregular was passing in front of it. Jason Wright of Penn State University was bold enough to suggest that what might be responsible for this dip in the light was an alien megastructure, a Dyson sphere, absorbing the star's solar energy so that it might be channelled for use by an extra-terrestrial civilization living on a planet in a nearby star system. Others, more soberly, proposed that the answer lay either in a swarm of comets encircling the star, or the wobbling motion of a young star surrounded by gas clouds. Since then there has been a storm of debate over what is going out there, although we should recall, of course, that KIC 8462852, otherwise known as Tabby's Star, is 1,480 years away. So it takes this long for its light, and its weirdness, to reach us.

The latest news is that a careful examination of 1,600 photos taken of KIC 8462852 in as many days between 2011 and 2015 has revealed something very disturbing indeed. In addition to the periodic dips of light of up to 22 percent, the star is losing its luminosity at a disturbing pace.

Across the first 1,000 days Kepler of observations, the star's light was found to have dimmed at a rate of around 0.34 percent per year. That isn't too bad, you might say. Yet over the next 200 days the star's brightness dropped by more than 2 percent before slowing down during the final days of observation (since then observations of KIC 8462852 using Kepler have been impossible as its lense adjustor is broken, meaning it cannot be repositioned manually). This means that in just under four and a half years the star has lost around 3 percent of its total luminosity. The two Caltech scientists who made the study (click to download the pre-print) also examined data from 193 nearby stars, as well as 355 stars that closely resemble Tabby's star and couldn't find anything else like it.

So if this study is correct in its findings, then this star is on a suicide course. A quick calculation suggests that if it continues to lose its light at a rate of 3 percent per year then it will cease to exist in just over 150 years! Or should I say, it will cease to exist around AD 686, just in time for King Cædwalla of Wessex to establish his overlordship of Essex in Anglo-Saxon England and Pope John V to die in Rome after a 12-month reign in which he has made handsome donations to the poor. Oh, sometimes it's confusing, isn't it!

Little Green Men-2

Anyway, quite clearly the demise of KIC 8462852 is something that will be played out in our own life times as well. I honesty don't believe it will disappear in just 150 years, although something is drastically wrong up there, and astronomers are trying to find out what. Clearly, it is not a swarm of comets causing all this mess, nor a young star spinning around with a dust cloud in front of it, so could the star's loss of luminosity really be down to an alien megastructure sucking away the star's energy at an alarming rate? Astronomers out there would love to tell you what they think might be going on. Yet not one will, because of three little letters - LGM. Indeed, cynics and skeptics are already referring to Tabby's Star as LGM-2.

So what is LGM, you ask?

LGM stands for Little Green Men, and LGM-1 was the name given to the source of a deep space radio signal detected back in 1967. Some astrophysicists genuinely supported the view that the signal was intelligent in origin and derived from an extra-terrestrial civilization. When it was eventually realised that the incredibly fast EM pulses were in fact coming from a fast-spinning neutron star called a pulsar there were a lot of scientists left with red faces. LGM-1 became PSR 1919+21 (PSR = pulsar) and the whole matter was dropped, but not forgotten. The acronym LGM became a warning to astronomers of the consequences of openly advocating aliens as a solution to an astronomical or astrophysical enigma. The LGM-2 tag now being applied to Tabby's Star is also a warning directed at those who prematurely claim that aliens are responsible for something they simply have no real answers for right now.

And this is right, we don't have all the answers right now, but secretly we can all speculate! Personally, I believe there is something quite extraordinary going on up there, although I do not believe that we have anything to worry about. I don't think there are aliens going around in megastructures sucking the life out of main sequence stars. It is possible, however, that what we are seeing is a natural process that occurs in the galaxy that necessitates the involvement of hyper-dimensional intelligences existing outside of normal space-time. Just a thought!

Anyway, here is the latest developments in the mystery as told by Centauri Dreams.

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