I want to revisit the paper on KIC 8462852 briefly this morning, as I’m increasingly fascinated with the astrophysics we’re digging into here. The fact that the star, some 1480 light years away, is also a candidate for further SETI investigation makes it all the more intriguing, but all my defaults lean toward natural processes, if highly interesting ones. Let’s think some more about what we could be looking at and why the ‘cometary’ hypothesis seems strongest.
Remember that we’re looking at KIC 8462852 not only because the Kepler instrument took the relevant data, but because the Kepler team took advantage of crowdsourcing to create Planet Hunters, where interested parties could sign up to study the light curves of distant stars on their home computers. KIC 8462852 has been causing ripples since 2011 because while we do seem to be seeing something passing between its light and us, that something is not a planet but a large number of objects in motion around the star. Some of the dips in starlight are extremely deep (up to 22 percent), and they are not periodic.
Here’s how Phil Plait describes the situation:
…it turns out there are lots of these dips in the star’s light. Hundreds. And they don’t seem to be periodic at all. They have odd shapes to them, too. A planet blocking a star’s light will have a generally symmetric dip; the light fades a little, remains steady at that level, then goes back up later. The dip at 800 days in the KIC 8462852 data doesn’t do that; it drops slowly, then rises more rapidly. Another one at 1,500 days has a series of blips up and down inside the main dips. There’s also an apparent change in brightness that seems to go up and down roughly every 20 days for weeks, then disappears completely. It’s likely just random transits, but still. It’s bizarre.
A ragged young debris disk would be the natural conclusion, but arguing against this is the fact that we don’t see the infrared excess that a dusty disk would create. I also got interested in what nearby objects might be doing to this star when I started digging into the paper, which is cited at the end of this piece. Yale postdoc Tabetha Boyajian and colleagues present an image from the UK Infrared telescope (UKIRT) that shows KIC 8462852 along with a second source of similar brightness, as shown in the image below. Notice the ‘extension’ of KIC 8462852 to the left.
Image: UKIRT image for KIC 8462852 and another bright star for comparison, showing that it has a distinct protrusion to the left (east). For reference, the grid lines in the image are 10?
× 10?. Credit: Tabetha Boyajian et al.
A follow-up Keck observation revealed what the UKIRT image suggested, that there is a faint companion star.
Image: Keck AO H-band image for KIC 8462852 showing the companion was detected with a 2? separation and a magnitude difference ?H = 3.8. Credit: Tabetha Boyajian et al.
This gets important as we consider the cometary debris hypothesis. The paper argues that the chance alignment possibility is only about one percent. If the companion is at the same distant as KIC 8462852, which is an F-class star, then we would be looking at an M-class red dwarf, roughly 885 AU distant from its companion. From the paper:
At this separation, the second star cannot currently be physically affecting the behavior of the Kepler target star, though could be affecting bodies in orbit around it via long term perturbations. If such a star is unbound from KIC 8462852, but traveling through the system perpendicular to our line of sight, it would take only 400 years to double its separation if traveling at 10 km sec?1. So, the passage would be relatively short-lived in astronomical terms.
Recall that the paper settles on cometary activity as the most likely natural explanation for the unusual KIC 8462852 light curve. We could be looking at a series of comet fragments seen close to the star as they move on a highly eccentric orbit, a collection of objects that has spread around the orbit and may be continuing to fragment. And as seen yesterday, Boyajian and team make the case that both thermal stress and the presence of super-Earth planets orbiting within 1 AU of the star could account for the tidal disruption that would have produced this scenario.
We’ve often discussed cometary disruptions in these pages, speculating on what the passage of a nearby star might do to comets in the Oort Cloud. As per the images above, it’s a natural speculation that the anomalies of KIC 8462852 are the result of a similar scenario. We have no idea whether the companion star is bound to KIC 8462852, but assume for a moment that it is not. A star passing close enough to this system has the potential for triggering a swarm of infalling comets. If the star is gravitationally bound, then we can invoke the so-called Kozai mechanism, ‘pumping up comet eccentricities,’ as the paper puts it. We can explore this hypothesis by studying the motion of the companion star to confirm its bound or unbound status.
The paper, as we saw yesterday, explores other hypotheses but settles on comet activity as the likeliest, given the data we currently have. The kind of huge collision between planets that would produce this signature would also be rich in infrared because of the sheer amount of dust involved, and we don’t see that. You can see why all this would catch the eye of Jason Wright (Penn State), who studies SETI of the Dysonian kind, involving large structures observed from Earth. Because if we’re looking at cometary chunks, some of these are extraordinarily large.
So what’s next? The paper explains:
First and foremost, long-term photometric monitoring is imperative in order to catch future dipping events. It would be helpful to know whether observations reveal no further dips, or continued dips. If the dips continue, are they periodic? Do they change in size or shape? On one hand, the more dips the more problematic from the lack of IR emission perspective. Likewise, in the comet scenario there could be no further dips; the longer the dips persist in the light curve, the further around the orbit the fragments would have to have spread. The possibility of getting color information for the dips would also help determine the size of the obscuring dust.
Monitoring of KIC 8462852 will continue from the ground thanks to the efforts of the MEarth project, which will begin the effort in the fall of this year, and that’s going to be useful for tracking the variability of the dips. Remember, too, that problem of lack of infrared excess. Those numbers could change if we really are witnessing a recent event. The paper continues:
Several of the proposed scenarios are ruled out by the lack of observed IR excess but the comet scenario requires the least. However, if these are time-dependent phenomenon, there could be a detectable amount of IR emission if the system were observed today. In the comet scenario, the level of emission could vary quite rapidly in the near-IR as clumps pass through pericenter (and so while they are transiting). The WISE observations were made in Q5, so detecting IR-emission from the large impact scenario, assuming the impact occurred in Q8 is also a possibility. We acknowledge that a long-term monitoring in the IR would be demanding on current resources/facilities, but variations detected in the optical monitoring could trigger such effort to observe at the times of the dips.
What a fascinating object! There has been a media flurry about the SETI possibilities, but that doesn’t mean that we shouldn’t investigate KIC 8462852 in SETI as well as astrophysical terms. No serious scientist is jumping to conclusions here other than to say that there is nothing in the laws of physics that would preclude the existence of civilizations more advanced than our own, and nothing that we know of that would keep us from detecting large artifacts. How they could be detected around other stars will be the subject of a forthcoming paper from Jason Wright and colleagues in The Astrophysical Journal, one we’ll obviously discuss here.
The paper is Boyajian et al., “Planet Hunters X. KIC 8462852 – Where’s the flux?” submitted to Monthly Notices of the Royal Astronomical Society (preprint).
Great post…
If it is a KII we may see interesting orbital changes taking place as everything is happening 1,480 years ago and KII isn’t likely to remain at rest…Lucky you’re young and will be around to check interesting changes taking place observing KIC 8462852 with superior instruments…
If a radio telescope were to focus on the primary, could it ALSO detect radio signals from the SECONDARY, and if so, could you tell EXACTLY WHICH STAR the radio signals were coming from? If signals from the secondary would not be detectable while focused on the primary, it would be IMPARITIVE to focus on the secondary, as well, because a K2 civilization would ALMOST CERTAINLY BE PRESENT AT BOTH STAES!
I remember reading this summer about GJ 436b and how it contained a comet like tail. While 436b orbited a much smaller red dwarf star, I wonder what sort of comet like behaviors a close in planet may exhibit around a more mature and hotter F3 class star. Perhaps ultraviolet wavelengths will shed further light on the system.
I also remember from one of the previous articles on this site discussion about unidirectional jets. Could non-uniformity in a jet produce said light curves? Maybe a volitional star is saying hello :)
These two papers about another KIC object which may be a disintegrating exoplanet similar to Mercury – might they be of any use in understanding what is going on with KIC 8462852?
http://arxiv.org/abs/1201.2662
Possible Disintegrating Short-Period Super-Mercury Orbiting KIC 12557548
S. Rappaport, A. Levine, E. Chiang, I. El Mellah, J. Jenkins, B. Kalomeni, E. S. Kite, M. Kotson, L. Nelson, L. Rousseau-Nepton, K. Tran
(Submitted on 12 Jan 2012 (v1), last revised 24 Mar 2012 (this version, v2))
We report here on the discovery of stellar occultations, observed with Kepler, that recur periodically at 15.685 hour intervals, but which vary in depth from a maximum of 1.3% to a minimum that can be less than 0.2%. The star that is apparently being occulted is KIC 12557548, a K dwarf with T_eff = 4400 K and V = 16. Because the eclipse depths are highly variable, they cannot be due solely to transits of a single planet with a fixed size. We discuss but dismiss a scenario involving a binary giant planet whose mutual orbit plane precesses, bringing one of the planets into and out of a grazing transit. We also briefly consider an eclipsing binary, that either orbits KIC 12557548 in a hierarchical triple configuration or is nearby on the sky, but we find such a scenario inadequate to reproduce the observations. We come down in favor of an explanation that involves macroscopic particles escaping the atmosphere of a slowly disintegrating planet not much larger than Mercury. The particles could take the form of micron-sized pyroxene or aluminum oxide dust grains. The planetary surface is hot enough to sublimate and create a high-Z atmosphere; this atmosphere may be loaded with dust via cloud condensation or explosive volcanism. Atmospheric gas escapes the planet via a Parker-type thermal wind, dragging dust grains with it. We infer a mass loss rate from the observations of order 1 M_E/Gyr, with a dust-to-gas ratio possibly of order unity. For our fiducial 0.1 M_E planet, the evaporation timescale may be ~0.2 Gyr. Smaller mass planets are disfavored because they evaporate still more quickly, as are larger mass planets because they have surface gravities too strong to sustain outflows with the requisite mass-loss rates. The occultation profile evinces an ingress-egress asymmetry that could reflect a comet-like dust tail trailing the planet; we present simulations of such a tail.
and…
http://arxiv.org/abs/1403.1879
Multiwavelength Observations of the Candidate Disintegrating sub-Mercury KIC 12557548b
Bryce Croll, Saul Rappaport, John DeVore, Ronald L. Gilliland, Justin R. Crepp, Andrew W. Howard, Kimberly M. Star, Eugene Chiang, Alan M. Levine, Jon M. Jenkins, Loic Albert, Aldo S. Bonomo, Jonathan J. Fortney, Howard Isaacson
(Submitted on 7 Mar 2014)
We present multiwavelength photometry, high angular resolution imaging, and radial velocities, of the unique and confounding disintegrating low-mass planet candidate KIC 12557548b. Our high angular resolution imaging, which includes spacebased HST/WFC3 observations in the optical, and groundbased Keck/NIRC2 observations in K’-band, allow us to rule-out background and foreground candidates at angular separations greater than 0.2 arcsec that are bright enough to be responsible for the transits we associate with KIC 12557548. Our radial velocity limit from Keck/HIRES allows us to rule-out bound, low-mass stellar companions to KIC 12557548 on orbits less than 10 years, as well as placing an upper-limit on the mass of the candidate planet of 1.2 Jupiter masses; therefore, the combination of our radial velocities, high angular-resolution imaging, and photometry are able to rule-out most false positive interpretations of the transits. Our precise multiwavelength photometry includes two simultaneous detections of the transit of KIC 12557548b using CFHT/WIRCam at 2.15 microns and the Kepler space telescope at 0.6 microns, as well as simultaneous null-detections of the transit by Kepler and HST/WFC3 at 1.4 microns. Our simultaneous HST/WFC3 and Kepler null-detections, provide no evidence for radically different transit depths at these wavelengths. Our simultaneous CFHT/WIRCam detections in the near-infrared and with Kepler in the optical reveal very similar transit depths (the average ratio of the transit depths at ~2.15 microns compared to ~0.6 microns is: 1.02 +/- 0.20). This suggests that if the transits we observe are due to scattering from single-size particles streaming from the planet in a comet-like tail, then the particles must be ~0.5 microns in radius or larger, which would favor that KIC 12557548b is a sub-Mercury, rather than super-Mercury, mass planet.
Astronomer Lucianne Walkowicz on SETI and Kepler
Published on Apr 15, 2015
Dr. Lucianne Walkowicz is an astronomer at the Adler Planetarium in Chicago. From 2008 – 2011 she was a Kepler Fellow in the study of planet-bearing stars at UC Berkeley, and from 2011 – 2014 she was a Henry Norris Russell Fellow at Princeton University. She continues to collaborate with Berkeley SETI Research Center astronomers; this video profile was recorded during a recent visit to Berkeley where Dr. Walkowicz gave an update on her work to search exoplanets for signs of extraterrestrial civilizations.
A TED Fellow, blogger, and artist, Lucianne is deeply committed to public outreach, including as part of the “Science Train” and “Intergalactic Travel Bureau” projects.
Check out Lucianne’s website:
http://tangledfields.com/
Follow us on Twitter: http://twitter.com/setiathome
Facebook: http://www.facebook.com/BerkeleySETI
https://www.youtube.com/watch?v=uxFHPMl50tc
Kepler, what an amazing, if flawed, piece of hardware.
I have no informed opinion about what is causing the observed light dips, but it’s awesome that Kepler was able to “see” these fluctuations.
We can only hope that there are more “Keplers” in the pipeline. No doubt that pipeline is tremendously expensive. Well worth it to enthusiasts such as visit this forum, but to the average guy?
It is so ironic, given the wealth of Kepler discoveries and data, that it has apparently failed to achieve its “prime directive”, discovering an earth sized planet orbiting its host “sunlike” star in its habitable zone.
A resident genius of considerable status explained to me that it turned out that the Sun is “not a sun-like star”! Most stars that look like the sun are in fact variable stars that confused Kepler in its photon counts. Then the wheels came off Kepler before it could observe long enough to adjust for the variances.
Best wishes to those who continue to dig into Kepler’s deep data mine, and best of luck to people who are doing their best to get another instrument like Kepler up there for more.
The James Webb telescope is going to kick Kepler’s butt, with all due respect.
If the cometary hypothesis is correct, the deep light light curves should show an IR spectrogram for water. I don’t see that in any of the data shown, but I might be missing this. The authors do not discuss this analysis, but I would have thought fragmenting comets should easily show water absorption lines in the star’s spectra. Is that wrong?
@Harry R Ray October 15, 2015 at 10:43
Not to worry! Most radio telescopes used for SETI at radio wavelengths have beam widths on the order of many arc minutes or wider. With the secondary of this start only about two arc seconds away, the beam of most SETI antennas would include both components. In the case of optical SETI, whether or not both stars would be observed at the same time depends critically on the details of the equipment used but I suspect that again both components would be observed simultaneously given the small separation. If some signal were to be found, interferometric radio observations with a large radiotelescope array could be made to pin down which component is broadcasting the signal. At optical wavelengths, modifications to existing equipment (e.g. a smaller aperture stop in the high speed photometer optical train) and making observations with arc second or better seeing could differentiate the source of an optical signal.
Astronomers have renamed the star WTF 001:
http://www.smh.com.au/technology/sci-tech/astronomy/its-either-aliens-or-a-swarm-of-comets-scientists-baffled-by-wtf-001-our-galaxys-strangest-star-20151014-gk9iwj.html
Even PBS’s Nova has gotten in on the act:
http://www.pbs.org/wgbh/nova/next/physics/bizarre-data-from-far-off-star-may-suggest-a-solar-collecting-megastructure/
Harry: “…could you tell EXACTLY WHICH STAR the radio signals were coming from?”
That depends on the mas separation of the targets and the resolution of the radio telescope. Offhand I’d guess no. However with VLBI the answer is almost certainly yes, with constraints.
@Alex Tolley October 15, 2015 at 13:01
‘If the cometary hypothesis is correct, the deep light light curves should show an IR spectrogram for water. I don’t see that in any of the data shown, but I might be missing this. The authors do not discuss this analysis, but I would have thought fragmenting comets should easily show water absorption lines in the star’s spectra. Is that wrong?’
The star emits a fair amount of U.V possibly destroying the water molecules faster than they can absorb it. Now that other star is very close, if it traveled through the system or close by material around both stars could have interacted with each other. I can’t seem to find an X-ray image of the star which could indicate the direction the red dwarf is going by the interaction of their solar winds.
Thank you Mr. Gilster. Another great article.
The considerable number of sound theories that could explain the signal signature shows how difficult it would be to have any provable theory of a structurally induced transit signal.
It would be interesting to see a list of hypothetical signal traits that would be undeniably sentient in origin. For instance: numeric (e.g., prime) relative distances between objects, signal features that can only come from hard angles, profiles that indicate a consistent repeating shape but with varying other properties wavelength (e.g., a large surface with controllable opacity or reflectivity)? Is anyone aware of a comprehensive list of signal traits that could provably not be naturally occurring?
It occurred to me that a compact black hole that is no accumulating matter could also cause this via gravitational lensing (light from the star is lensed so it fans out, causing apparent dimming). If it in turn is co-orbiting another object that would cause a chaotic yet cyclical pattern.
I didn’t see that mentioned in the paper, but it should be straightforward to model how that would appear to kepler (my guess is that the light would fan out to adjacent pixels, which would see an increase in flux that offsets the dimming of the target, and if so, that’s confirmatory evidence of lensing as the culprit).
Good article and links to other informative papers right here in Jason T. Wright’s AstroWright blog:
http://sites.psu.edu/astrowright/2015/10/15/kic-8462852wheres-the-flux/
Both D800 and D1500 transit events hiding 15% and 22% of the star angular area imply two possible scenarios:
1) the objects causing the shadow are orbiting around KIC 8462852, and they are huge
2) the objects causing the shadow are actually closer to us than to the star
if 1) is the right answer, then they are big enough to be spherical by self-gravitation, but neither of the irregular transits are time-symmetric, which means that the shapes depart significantly from circular
If these are explainable by a natural object, the most likely scenario in my opinion is 2), which probably means that there is a much smaller self-gravitating debris cloud somewhere in the middle of the line of sight between KIC 8462852 and us
No, this possibility doesn’t seem to have been properly considered in the paper
Hypothesis 2) sounds like the most reasonable natural explanation, since the farther are the objects from KIC846852 the better, as it explains the lack of IR signature. The closer they are to us the better, as it requires smaller bodies to produce the same occultation
If my back of the envelope scaling is correct, the high frequency 20 day features that are there for 0.75 of the data (roughly) need to be at about 0.5 AU to collect as much energy as the big events much further out. The size scales similarly of course. My scaling might be wrong, done quickly before going off to give an astro exam!
Interesting. but you don’t give the units in relation to the image: it’s 1,000 x 1,000, but what – arcsecs? milliarcsecs? AU? LY? Similarly for the caption to the next image. Without units, it’s very hard to assess anything.
Great article! It’s perhaps the most intriguing finding as far as possible extra-terrestrial existence yet. At the very least if it is something natural, like pulsars were in the 1960s, it could be a new phenomena discovery. But at the most it could be finally after 50 years of searching evidence of some advanced technology other than our own. I’m sure Mr. Carl Sagan would be excited, stress that we keep an open mind but also hone in on it & find out all we can & find out what it is. The star is around 1400 light years away so what we’re seeing is 1400 years old, not that old in the cosmic sense. What interests me is what are the next immediate steps going to be? I’m looking forward to Mr. Wright’s paper, but as far as observation & to try and get more answers what are the next immediate steps. Visible ground monitoring before the end of this year? And when will the first focused radio scans take place? Shouldn’t we be able to tell relatively quickly whether we are looking at evidence of aliens or a natural phenomena?
To engage in a bit of wild speculation, IF it is some type of alien sphere or solar-catching array, it’s reasonable to assume that this would be a species far more advanced than us, at least as of ~1400 years ago. If we determine that the objects causing the ~20% diminishing of the star’s visible light are alien, then what Kardashev Scale might we looking at? We could be looking at the zenith of their technology. If they are far older than us, it’s probable that they had/have absolutely no idea we exist, from the 1400 light year distance. Unless they had some ability to detect atmospheric signatures for life signs from that distance. But this is pure, fun speculation of course :)
What should we be looking out for as the next big milestone in this for getting some answers one way or another? Either way it’s exciting..in the 1960s scientists had no idea about pulsars and that was a cool new discovery in the nuclear age. Perhaps this is just some unknown new natural solar phenomena but it would seem to be very unusual especially for such a mature star. Interested in your thoughts, and thanks for the excellent insights!
Rob J.
If what we are looking at is evidence of alien technology once we eliminate the natural hypotheses, I’d agree we should look for undeniable signs of universal intelligence, patterns, numerical, anything that does not occur in nature. I always pictured SETI making contact via a radio signal, of prime numbers or some universal mathematical pattern, but that would differ from this in that it would be some advanced species consciously emitting a signal in hopes that someone else hears it. Maybe they don’t use radio waves at all, or any kind of radio astronomy themselves. They could be a coldly practical, insular species, focused on themselves and nobody else in the cosmos. Or they could be adventurous, but if what we’re seeing is some kind of Dyson’s sphere, we’d know that they’re definitely quite advanced on some level. Or they were, as of ~1400 years ago.
But if you think about it, look at humans, while we are innately curious about the cosmos, and wondering if we’re alone, we’re also cautious, and very self-centered and inward in many ways. We can’t know what evolutionary and historical background some advanced alien species comes from.
So the inner explorer and optimist in me says that this potentially could be a more feasible way to “make contact” as it were, even though IF we determine that KIC star supports intelligent life, we aren’t actually receiving or responding to any message from them. In all probability, they don’t know we exist at all. They may be very focused on their own immediate tasks, & have no concept of anyone else besides them being in the galaxy. So if we determine that the KIC star has an intelligent species living nearby, we’re basically getting an anonymous, stealthy glimpse into their existence, which is very cool in a way. If they are highly advanced, perhaps they’ve figured out a way for interstellar travel, but most probably they don’t even know about earth at all in the least.
I’m just holding my breath here I’ll also be interested to see what Dr. Hawking says on this if he has not already weighed in on it. I could speculate on this endlessly, it’s super exciting, as someone who’s always followed SETI and hoped for a result, but we need more data! It could be purely comets but we should be open minded & just let the facts take us where they may :)
Terry Moseley writes:
Wow, sorry! I’m glad you caught that. It was a transcription error, and I’ve corrected it in the captions. Thanks.
@CharlesJQuarra: I’ve heard similar ideas around and about, but I don’t see what these nearby mystery objects between us and the distant star could be. To be passing between us and the star with sufficient frequency to cause the dips theywould have to be hugely numerous if randomly scattered (and we’d see thsi effect on other stars), or else lined up just right between us and KIC 8462852, which seems like a bit of a big coincidence – although if there’s a string of shattered comet fragments out there it makes sense it’s occult something at some point, but would such an explanation hold across the time period these dips are observed at?
Andrew LePage and Ron S: Thanks for answering my question. NOW: I thought of a few more overnight! FIRST: An F3 star stays on the main sequience fir only 2 to 3 billion(heavilly dependant on metallicity) years. So, unless life can evolve much faster than Earth’s did, this would seem to NEGATE the possibility of the K2 civilization ORIGINATING on the PRIMARY. Am I right? SECOND: Being ONLY 800 or so AU from the primary, a secondary in a CIRCULAR orbit would have, over BILLIONS OF YEARS, TOTALLY DISRUPTED the Oort Cloud of the PRIMARY by now! Therefore, only a very eccentric orbit with an apastron similar to the separation between Proxima and Alpha Centauri, OR, a “just passing through” scenario similar to what happened between the Sun and Scoal’s Star 70,000 years ago(but at a MUCH CLOSER SEPARATION) would fit the “comet swarm” explanation. Am I right? FINALLY: I thought of a really WILD(and therefore probably very WRONG) scenario for megastructures orbiting 100 AU from the primary. Here goes! The secondary is a MUCH OLDER STAR than the primary with a K2 civilization capable of building a “STAR”ship mentioned several times on this website, which MOVED the secondary into an orbit around the primary, and the dips in the light curves represent the DECONSTRUCTED REMANENTS OF THAT “STAR”SHIP! Any comments?
Is it also possible that aside from it being some type of Dyson Sphere that if a civilization were advanced enough, the dips in light from the star could be a purposeful attempt at a beacon for anyone who could detect it?
Also there can be many different types & forms of a Dyson Sphere too, and perhaps (purely speculating) this could be one that has only partially been completed as of ~1400 years ago. Ms. Boyajian says she thinks it may be large swaths of cometary dust clouds but I just find that very unlikely. Could cometary fragments or dust cause a 20% dip in solar visibility? Jupiter would only produce around 1% of the same effect around our Sun for instance. So whatever it is has to be VERY big.
@Harry R Ray October 16, 2015 at 9:48
‘The secondary is a MUCH OLDER STAR than the primary with a K2 civilization capable of building a “STAR”ship mentioned several times on this website, which MOVED the secondary into an orbit around the primary, and the dips in the light curves represent the DECONSTRUCTED REMANENTS OF THAT “STAR”SHIP! Any comments?’
So what happened to the other ‘older’ stars inhabitants during the moving of the structure, surely they would have built two spheres, one around each star?
Your conjectures 1 & 2 seem reasonable. However, your third one seems just to indicate how much you want to believe that the anomalies are a sign of an advance alien civilisation.
A thought, not having analyzed the spectra or patterns yet:
What would a spacecraft or group look like if it were traveling from that star to earth?
I think we would expect to see the occultation of the distant starlight in a non-periodic pattern.
What about ejecta from that system heading directly toward us?
What gets me is the immense dips the 20% & another around 15%? That’s absolutely massive, to temporarily block a star! I can see why we’re so intrigued. Have to see where the facts take us, but I just don’t see how massive cometary fragments & dust could produce that. Perhaps a binary brown dwarf star, not visible yet but massive enough to cause the anomaly? Otherwise if further observations rule those out we have to start thinking about possible alien activity.
Question-do we know habitable zone of this star? Position of the object vs the zone?
Are we not getting carried away a bit here? A spacecraft group blocking 20% of the light of a main sequence star? The total cross-sectional area would have to be much greater than that of Jupiter, unless they were very far away from the star already. And that would presume that they are travelling in a dead straight line from the star to us, which given the relative space motions is of almost zero likelihood.
Let’s keep a sense of proportion here.
@Rob
A large binary brown dwarf star would give very symmetrical and uniform light curves. The ones they have are anything but that with “100’s of dips” and lop-sided gradients.
What is the evidence that this red dwarf is actually 800 AU or so from the primary and not in the foreground or background …and thus 800 AU is only a minimum possible separation?
Michael: My point exactly! The secondary is TOO DIM to analize ANY light curves from the Kepler database, and; since it was JUST RECENTLY DISCOVERED, it would have NOT have been one of the 156,000 stars to get EXTRA ATTENTION! We should now HEAVILLY FOCUS on the secondary! I do not know if there is going to be any OVERLAP of the Kepler and TESS fields, but(correct me if I am wrong)I seriously doubt it. A long-term search by Spitzer is possible in the final stages of its operation, but we may have to wait for LSS, WFIRST, or PLATO for any difinitave data!
Let’s assume (for fun), that it is a super structure. And let’s pretend that this civilization is blinking a message. It would be interesting if a cryptologist could decipher something out of this data. This is going on the assumption that we have received contact from an alien civilization and now need to decode it. Fascinating. And by the way, of all the theories….I’m cheering for the structure scenario.
@Wojciech J October 17, 2015 at 16:25
Sorry did not see this,
‘Question-do we know habitable zone of this star? Position of the object vs the zone?’
The HZ for this star starts at around 2 AU to 3AU, beyond Mars and about 1/3 the way to Jupiter. Now the objects range up to 4 – 500 000 km and the distance to the objects if you use the second similar dip as an orbit (40 days) one would be around the orbit of Mercury if in a circular orbit! To have that size object in dust it would emit heavily in the infrared and ice would not survive so it surely must be further out.
Well, if it’s a message, I would only give them 3 out of 10 for grammar, 4 out of 10 for spelling, and 1 out of 10 for clarity of expression!
Here is an article about what planets can do to the dust and I suppose ice grains in the Zodiac plane.
‘A resonant ring structure created by a planet on a circular
orbit in an exozodiacal cloud typically exhibits the following
asymmetries (Stark & Kuchner 2008).
1. A density deficit, or “gap,” near the location of the planet.
2. A density enhancement, or “clump,” trailing the planet.
3. A second clump leading the planet, typically with a density
less than that of the trailing clump.
http://iopscience.iop.org/article/10.1088/0004-6256/142/4/123/pdf
We have a leading and trailing dips of a symmetrical object.
That paper indicates that it is very unlikely that it’s the explanation for the mystery irregular light curve dips. Quote:
1. “The transit light curves created by dusty resonant ring structures typically exhibit two broad transit minima that lead and trail the planetary transit.” That effect is not observed in this case – the dips are of greatly uneven depth, asymmetric, and irregular.
2. Quote: “We find that Jupiter-mass planets embedded within disks hundreds of times denser than our zodiacal cloud can create resonant ring structures with transit depths up to ?10?4. Resonant rings produced by planets more or less massive than Jupiter produce smaller transit depths.” So even Jupiter sized planets, in a dust disc hundreds of times denser than ours, would only produce dips of 0.01%. The observed dips reach 20%.
Another explanation is needed!
Here is my theory. The body with unknown objects could be a mirror image of our own planet having satellites orbiting the object. It may sound crazy, but think about it. We theorize our Sun and our planet are ideal conditions for life because its only what we know and are familiar with. Rules are made and rules can be broken. My belief is KIC846852 is a planet with life. A possible civilization with satellites and similar activity as we have here on our planet. KIC846852 could be our twin!
Hi Joe,
Surely that’s wishful thinking? For a start, it’s a star, not a planet! As for what caused the variations in the light we received from it, that’s most likely a family of comets, or a large broken up comet. See http://www.sciencedaily.com/releases/2015/11/151125084108.htm?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+sciencedaily%2Ftop_news%2Ftop_science+%28ScienceDaily%3A+Top+Science+News%29
Terry
800 days – the dim drops slowly then rises rapidly – This could be the result of the object having a mountain rage on it that is narrow and then suddenly increases in width greatly . An asteroid tumbling counter-clockwise to Earth if the asteroid and KIC were both in direct line with Earth.
1500 days – blips up and down inside of the main dips. Possible large asteroid that has holes through the entire asteroid that would allow some of the blocked light to pass through. Not certain if such an asteroid would able to exist due to natural variables such as impacts. Mining for rare minerals in the asteroid could explain the blips.
Brightness goes up and down every 20 twenty days for weeks and then disappears.
Variable star – Intrinsic variables, whose luminosity actually changes; for example, because the star periodically swells and shrinks. What would cause KIC to swell?But more importantly shrink by 15% and 22%.
Is it possible that 2 planets collided at a trajectory that caused a large heap of planetary debris to orbit the star ?
There should be an infrared signature if so.