# Weird star changes in brightness due to... aliens? **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [October 14, 2015, 1:23pm UTC](https://boards.straightdope.com/t/weird-star-changes-in-brightness-due-to-aliens/734624 "2015-10-14T13:23:57Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![snfaulkner](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/snfaulkner/32/433_2.png) [@snfaulkner](https://boards.straightdope.com/u/snfaulkner)\ **Post date:** [October 14, 2015, 10:52pm UTC](https://boards.straightdope.com/t/weird-star-changes-in-brightness-due-to-aliens/734624/21 "2015-10-14T22:52:15Z")
The obvious answer is that it is aliens having a rave. Duh! ---
**Author:** ![Projammer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/projammer/32/559_2.png) [@Projammer](https://boards.straightdope.com/u/Projammer)\ **Post date:** [October 15, 2015, 12:53am UTC](https://boards.straightdope.com/t/weird-star-changes-in-brightness-due-to-aliens/734624/22 "2015-10-15T00:53:22Z")
Incomplete Dyson sphere or ring. Whether it hasn’t been finished or has been partially destroyed is the real question. ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [October 16, 2015, 6:59pm UTC](https://boards.straightdope.com/t/weird-star-changes-in-brightness-due-to-aliens/734624/23 "2015-10-16T18:59:25Z")
> [@Measure\_for\_Measure](#): > > The star is 1500 light years away, and was picked up by Kepler which scanned 150,000 stars. Bear the latter in mind: an experiment with such a high sample size is likely to turn up a number of astronomically interesting outliers. The comet story may not be likely on its own, but that’s the same for any 1 in 150,000 event. > … Wouldn’t an advanced alien race count as an astronomically interesting outlier? Just saying. Although it certainly is just one of some unknown large number of other possibilities and as such, unlikely. ---
**Author:** ![iiandyiiii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/iiandyiiii/32/7924_2.png) [@iiandyiiii](https://boards.straightdope.com/u/iiandyiiii)\ **Post date:** [January 15, 2016, 10:38pm UTC](https://boards.straightdope.com/t/weird-star-changes-in-brightness-due-to-aliens/734624/24 "2016-01-15T22:38:58Z")
Bumping this; a bit of [news](https://www.newscientist.com/article/dn28786-comets-cant-explain-weird-alien-megastructure-star-after-all/) – whatever’s causing it isn’t comets. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [January 16, 2016, 5:37am UTC](https://boards.straightdope.com/t/weird-star-changes-in-brightness-due-to-aliens/734624/25 "2016-01-16T05:37:55Z")
> [@iiandyiiii](#): > > Bumping this; a bit of [news](https://www.newscientist.com/article/dn28786-comets-cant-explain-weird-alien-megastructure-star-after-all/) – whatever’s causing it isn’t comets. Nice nod to Bowie in the article’s subheads there. 🙂 ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [January 16, 2016, 5:54am UTC](https://boards.straightdope.com/t/weird-star-changes-in-brightness-due-to-aliens/734624/26 "2016-01-16T05:54:48Z")
I’m wondering if this could be caused by aging of the photographic plates? I assume that they looked to make sure that other stars didn’t also dim. ---
**Author:** ![Balance](https://avatars.discourse-cdn.com/v4/letter/b/ccd318/32.png) [@Balance](https://boards.straightdope.com/u/Balance)\ **Post date:** [January 16, 2016, 6:18am UTC](https://boards.straightdope.com/t/weird-star-changes-in-brightness-due-to-aliens/734624/27 "2016-01-16T06:18:36Z")
It’s actually a binary system with a (relatively) low-mass captured neutron star. The gradual dimming is caused by the secondary siphoning off material from the photosphere, while the erratic changes in intensity reflect a combination of induced flares and partial to full occlusion by the secondary and its accretion disk. There may also be one or more other bodies with orbits perturbed by the presence of the secondary. I actually don’t know jack about this, I just think it sounds cool. ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [January 16, 2016, 2:28pm UTC](https://boards.straightdope.com/t/weird-star-changes-in-brightness-due-to-aliens/734624/28 "2016-01-16T14:28:16Z")
> [@Balance](#): > > It’s actually a binary system with a (relatively) low-mass captured neutron star. The gradual dimming is caused by the secondary siphoning off material from the photosphere, while the erratic changes in intensity reflect a combination of induced flares and partial to full occlusion by the secondary and its accretion disk. There may also be one or more other bodies with orbits perturbed by the presence of the secondary. > > I actually don’t know jack about this, I just think it sounds cool. No; a system with an actively accreting neutron star would be very bright in x-rays, and I presume this is not the case. A tangentially related question: in one article I was reading about it, the author doubted it could be an alien civilization because covering 19% of a star in just a century seemed very implausible to him. This led me to wonder just how fast a technological civilization can expand. (I’ll set aside self-reproducing machines for the moment and consider the whole civilization as a self-reproducing machine.) As the nearest analogy we have experience with, the Baby Boom years are an example of how fast a technological civilization can expand in good times. Measured in population and gross domestic product, how much did the United States grow during the quarter-century from 1945 to 1970? I suspect the USA matched or exceeded 19% growth per century. ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [January 16, 2016, 2:42pm UTC](https://boards.straightdope.com/t/weird-star-changes-in-brightness-due-to-aliens/734624/29 "2016-01-16T14:42:48Z")
Can we really say what is or isn’t plausible for an advanced civilization? Yes, this is almost certainly some natural phenomenon we just don’t understand yet, but I don’t get the argument that it’s not plausible for a civilization to do it when we’re talking about advanced technologies we know nothing about. ---
**Author:** ![Balance](https://avatars.discourse-cdn.com/v4/letter/b/ccd318/32.png) [@Balance](https://boards.straightdope.com/u/Balance)\ **Post date:** [January 16, 2016, 8:55pm UTC](https://boards.straightdope.com/t/weird-star-changes-in-brightness-due-to-aliens/734624/30 "2016-01-16T20:55:11Z")
> [@Lumpy](#): > > No; a system with an actively accreting neutron star would be very bright in x-rays, and I presume this is not the case. True, but Phil’s article didn’t say anything about x-rays, even though he mentioned lack of infrared emissions ruling out dust. I’d think it’s something they would have looked at, though. How much would the orientation of the disk affect the amount of x-rays we’d expect to pick up? If the secondary’s orbit is such that the plane of the disk never fully faces us, might the x-ray emissions that reach us be low enough not to stand out? > [@](#): > > A tangentially related question: in one article I was reading about it, the author doubted it could be an alien civilization because covering 19% of a star in just a century seemed very implausible to him. This led me to wonder just how fast a technological civilization can expand. (I’ll set aside self-reproducing machines for the moment and consider the whole civilization as a self-reproducing machine.) > > As the nearest analogy we have experience with, the Baby Boom years are an example of how fast a technological civilization can expand in good times. Measured in population and gross domestic product, how much did the United States grow during the quarter-century from 1945 to 1970? I suspect the USA matched or exceeded 19% growth per century. I think it would depend on how they’re producing whatever is causing the occlusion. If they had a huge stockpile of raw materials in place (maybe a trojan point full of asteroids) and were producing enormous thin-film mirrors, it would be more plausible than building structural panels. In between those extremes, they could be inflating asteroids to make bubble habitats or something. That would be an application for the mirrors. If we want to get _really_ sci-fi, there might not be any megastructures. They could be manipulating the star itself somehow. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [January 16, 2016, 9:50pm UTC](https://boards.straightdope.com/t/weird-star-changes-in-brightness-due-to-aliens/734624/31 "2016-01-16T21:50:36Z")
> [@](#): > > Quoth **davidm** : > > I’m wondering if this could be caused by aging of the photographic plates? I assume that they looked to make sure that other stars didn’t also dim. This was discovered by the Kepler satellite, long after the era of photographic plates. Kepler is in fact designed specifically to look for dips in the light output of stars, and is calibrated for that purpose. As I understand it, this effect for this star shows up _only_ in the brightness. The star’s specrum doesn’t change at all. Most variable stars will show some sort of spectral effect, such as a Doppler shift from the surface expanding and contracting, or from it orbiting another star, or a shift in the blackbody emission from a temperature variation. Without any spectral signature, this is almost certainly due to _something_ obstructing part of the star; it’s just a question of what. My personal guess is that it’s a bunch of hot Jupiters in chaotic orbits. It’s very rare to find anything in astronomy with chaotic orbits, since those tend to eject or eat objects until what’s left isn’t chaotic any more… but as mentioned, we’re working with a very large sample size here, so finding one rare circumstance isn’t too surprising. Since the star itself appears to be of a reasonably mature age, this presumably means that something seriously disrupted the orbits of its planets, in the recent past. ---
**Author:** ![Balance](https://avatars.discourse-cdn.com/v4/letter/b/ccd318/32.png) [@Balance](https://boards.straightdope.com/u/Balance)\ **Post date:** [January 16, 2016, 10:00pm UTC](https://boards.straightdope.com/t/weird-star-changes-in-brightness-due-to-aliens/734624/32 "2016-01-16T22:00:05Z")
> [@Chronos](#): > > My personal guess is that it’s a bunch of hot Jupiters in chaotic orbits. It’s very rare to find anything in astronomy with chaotic orbits, since those tend to eject or eat objects until what’s left isn’t chaotic any more… but as mentioned, we’re working with a very large sample size here, so finding one rare circumstance isn’t too surprising. Since the star itself appears to be of a reasonably mature age, this presumably means that something seriously disrupted the orbits of its planets, in the recent past. That’s more or less what I was thinking when I mentioned a captured object: something has recently (on the scale of such things) messed with the system somehow. ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [January 17, 2016, 3:23pm UTC](https://boards.straightdope.com/t/weird-star-changes-in-brightness-due-to-aliens/734624/33 "2016-01-17T15:23:15Z")
> [@Chronos](#): > > This was discovered by the Kepler satellite, long after the era of photographic plates. Kepler is in fact designed specifically to look for dips in the light output of stars, and is calibrated for that purpose. > > As I understand it, this effect for this star shows up _only_ in the brightness. The star’s specrum doesn’t change at all. Most variable stars will show some sort of spectral effect, such as a Doppler shift from the surface expanding and contracting, or from it orbiting another star, or a shift in the blackbody emission from a temperature variation. Without any spectral signature, this is almost certainly due to _something_ obstructing part of the star; it’s just a question of what. > > My personal guess is that it’s a bunch of hot Jupiters in chaotic orbits. It’s very rare to find anything in astronomy with chaotic orbits, since those tend to eject or eat objects until what’s left isn’t chaotic any more… but as mentioned, we’re working with a very large sample size here, so finding one rare circumstance isn’t too surprising. Since the star itself appears to be of a reasonably mature age, this presumably means that something seriously disrupted the orbits of its planets, in the recent past. I wasn’t talking about what was discovered by Kepler. I was talking about the latest news, which was posted by **iiandyiiii** , about what was found in the old photographic plates. > **[Comets can't explain weird 'alien megastructure' star after all](https://www.newscientist.com/article/dn28786-comets-cant-explain-weird-alien-megastructure-star-after-all/)** > > A star called KIC 8462852, or Tabby's star, has been behaving oddly since 1890, not just recently as had been thought – and astronomers have no idea why ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [January 17, 2016, 4:26pm UTC](https://boards.straightdope.com/t/weird-star-changes-in-brightness-due-to-aliens/734624/34 "2016-01-17T16:26:57Z")
I discovered the answer to my own question earlier: During the peak of the Baby Boom years, the US GDP nearly quintupled in twenty-five years, from $228 billion in 1945 to $1075 billion in 1970. And that was the average; growth exceed 6% annually in seven of those years. In the same roughly one-generation period, the US population increased from 140 million to 205 million. Population growth exceeded 1.60% annually from 1947 (end of WW2) to 1961 (introduction of birth-control pills?), with a peak of 2% in 1950. So let’s say that a technological civilization at least as sophisticated as ours could maintain a 1.5% growth rate annually, and that in this case that was the growth rate of energy capture by space colonies. That would work out to over 4x increase per century. Interesting question: do the photographic plates register a linear or exponential decrease in brightness; or can they tell? ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [January 17, 2016, 4:35pm UTC](https://boards.straightdope.com/t/weird-star-changes-in-brightness-due-to-aliens/734624/35 "2016-01-17T16:35:38Z")
> [@Lumpy](#): > > … > Interesting question: do the photographic plates register a linear or exponential decrease in brightness; or can they tell? That’s the kind of thing I’m wondering about. What can they tell and how can they tell it? How uniform were the exposures, the processing, and the chemistry of the plates over all of that time? Do the images fade at all with age? The earliest are from the late 1800s, so they aren’t exactly high tech. My guess is that they’re measuring the brightness relative to the rest of the stars on a given plate. At least I hope that’s what they’re doing. That would at least give a relatively accurate measurement of changes in one star over time. ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [January 17, 2016, 4:42pm UTC](https://boards.straightdope.com/t/weird-star-changes-in-brightness-due-to-aliens/734624/36 "2016-01-17T16:42:37Z")
In regards to astronomy and photographic plates. Photographic plates were used in professional astronomy from almost the day film was invented till at least the early 80’s. Much good and precise science was done with said plates. Those old plates are a treasure trove of information. Astronomers spent decades developing techniques to get good info from photographic plates. Plates, even very aged, are plenty good enough to “measure” a star’s brightness in the past, particularly something as large as a 20% variation. As a semi educated WAG, I’d say with good technique, something more along the lines of 1% would be easily doable. ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [January 17, 2016, 4:49pm UTC](https://boards.straightdope.com/t/weird-star-changes-in-brightness-due-to-aliens/734624/37 "2016-01-17T16:49:04Z")
> [@davidm](#): > > My guess is that they’re measuring the brightness relative to the rest of the stars on a given plate. At least I hope that’s what they’re doing. That would at least give a relatively accurate measurement of changes in one star over time. Long story short that IS how they do it. ---
**Author:** ![Chefguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chefguy/32/138_2.png) [@Chefguy](https://boards.straightdope.com/u/Chefguy)\ **Post date:** [January 17, 2016, 5:21pm UTC](https://boards.straightdope.com/t/weird-star-changes-in-brightness-due-to-aliens/734624/38 "2016-01-17T17:21:28Z")
> [@TriPolar](#): > > That’s why fluorescent lights start flickering sometimes. I got it, and it made this old electrician laugh. ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [January 17, 2016, 6:18pm UTC](https://boards.straightdope.com/t/weird-star-changes-in-brightness-due-to-aliens/734624/39 "2016-01-17T18:18:04Z")
> [@billfish678](#): > > Long story short that IS how they do it. Maybe all of the other stars have gotten 19% brighter. 😛 ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [July 7, 2016, 8:42pm UTC](https://boards.straightdope.com/t/weird-star-changes-in-brightness-due-to-aliens/734624/40 "2016-07-07T20:42:09Z")
A Kickstarter project has successfully funded 1 year of access to the [Las Cumbres Observatory Global Telescope Network](http://lcogt.net/) to observe the star and try to catch and record and dimming incidents. [https://www.kickstarter.com/projects/608159144/the-most-mysterious-star-in-the-galaxy/description](https://www.kickstarter.com/projects/608159144/the-most-mysterious-star-in-the-galaxy/description) > [@](#): > > Primary goals > > With your support through this Kickstarter, we will be able to continue monitoring this star and it will give you the opportunity to be a part of it! > > Our initial requested funds will cover all expenses for one year of monitoring the star. This will include a total of two hours per night dedicated to observing it. Observations will be dispersed for even temporal coverage throughout the night, and each pointing will cycle through a set of filters to give us the brightness at a range of colors. So maybe we’ll have some answers. [Previous page](https://boards.straightdope.com/t/weird-star-changes-in-brightness-due-to-aliens/734624.md?page=1) [Next page](https://boards.straightdope.com/t/weird-star-changes-in-brightness-due-to-aliens/734624.md?page=3)