Either stars are strange, or there are 234 aliens trying to contact us

October 20, 2016 by Evan Gough, Universe Today
Either stars are strange, or there are 234 aliens trying to contact us
A portion of the 234 stars that are sources of the pulsed ETI-like signal. Note that all the stars are in the narrow spectral range F2 to K1, very similar to our own sun. Credit: Ermanno F. Borra and Eric Trottier This graph shows the number of detected signals by Spectral Type of star. Credit: Ermanno F. Borra and Eric Trottier

We all want there to be aliens. Green ones, pink ones, brown ones, Greys. Or maybe Vulcans, Klingons, even a being of pure energy. Any type will do.

That's why whenever a mysterious signal or energetic fluctuation arrives from somewhere in the cosmos and hits one of our many telescopes, headlines erupt across the media: "Have We Finally Detected An Alien Signal?" or "Have Astronomers Discovered An Alien Megastructure?" But science-minded people know that we're probably getting ahead of ourselves.

Skepticism still rules the day when it comes to these headlines, and the events that spawn them. That's the way it should be, because we've always found a more prosaic reason for whatever signal from space we're talking about. But, being skeptical is a balancing act; it doesn't mean being dismissive.

What we're talking about here is a new study from E.F. Borra and E. Trottier, two astronomers at Laval University in Canada. Their study, titled "Discovery of peculiar periodic spectral modulations in a small fraction of solar type stars" was just published at arXiv.org. ArXiv.org is a pre-print website, so the paper itself hasn't been peer reviewed yet. But it is generating interest.

The two astronomers used data from the Sloan Digital Sky Survey, and analyzed the spectra of 2.5 million stars. Of all those stars, they found 234 stars that are producing a puzzling signal. That's only a tiny percentage. And, they say, these signals "have exactly the shape of an ETI signal" that was predicted in a previous study by Borra.

Either stars are strange, or there are 234 aliens trying to contact us
This graph shows the number of detected signals by Spectral Type of star. Credit: Ermanno F. Borra and Eric Trottier

Prediction is a key part of the scientific method. If you develop a theory, your theory looks better and better the more you can use it to correctly predict some future events based on it. Look how many times Einstein's predictions based on Relativity have been proven correct.

The 234 stars in Borra and Trottier's study aren't random. They're "overwhelmingly in the F2 to K1 spectral range" according to the abstract. That's significant because this is a small range centred around the spectrum of our own Sun. And our own Sun is the only one we know of that has an intelligent species living near it. If ours does, maybe others do too?

The authors acknowledge five potential causes of their findings: instrumental and data reduction effects, rotational transitions in molecules, the Fourier transform of spectral lines, rapid pulsations, and finally the ETI signal predicted by Borra (2012). They dismiss molecules or pulsations as causes, and they deem it highly unlikely that the signals are caused by the Fourier analysis itself. This leaves two possible sources for the detected signals. Either they're a result of the Sloan instrument itself and the data reduction, or they are in fact a signal from extra-terrestrial intelligences.

The detected signals are pulses of light separated by a constant time interval. These types of signals were predicted by Borra in his 2012 paper, and they are what he and Trottier set out to find in the Sloan data. It may be a bit of a red flag when scientist's find the very thing they predicted they would find. But Trottier and Borra are circumspect about their own results.

As the authors say in their paper, "Although unlikely, there is also a possibility that the signals are due to highly peculiar chemical compositions in a small fraction of galactic halo stars." It may be unlikely, but lots of discoveries seem unlikely at first. Maybe there is a tiny subset of stars with chemical peculiarities that make them act in this way.

Either stars are strange, or there are 234 aliens trying to contact us
A portion of the 234 stars that are sources of the pulsed ETI-like signal. Note that all the stars are in the narrow spectral range F2 to K1, very similar to our own sun. Credit: Image: Ermanno F. Borra and Eric Trottier

To sum it all up, the two astronomers have found a tiny number of stars, very similar to our own Sun, that seem to be the source of pulsed signals. These signals are the same as predicted if a technological society was using powerful lasers to communicate with distant stars.

We all want there to be aliens, and maybe the first sign of them will be pulsed light signals from stars like our own sun. But it's all still very preliminary, and as the authors acknowledge, "…at this stage, this hypothesis needs to be confirmed with further work."

That further work is already being planned by the Breakthrough Listen Initiative, a project that searches for intelligent life in the cosmos. They plan to use the Automated Planet Finder telescope at the Lick Observatory to further observe some of Borra's 234 stars.

The Breakthrough team don't seem that excited about Borra's findings. They've already poured cold water on it, trotting out the old axiom that "Extraordinary claims require extraordinary evidence" in a statement on Borra's paper. They also give Borra's findings a score of 0 to 1 on the Rio Scale. The Rio Scale is something used by the international SETI community to rank detections of phenomena that could indicate advanced life beyond Earth. A rating of 0 to 1 means its insignificant.

Better rein in the headline writers.

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18 comments

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Sonhouse
4.8 / 5 (5) Oct 20, 2016
I suspect they will find systemic errors when corrected negate the whole thing, just like the supposed faster than light neutrino's found a few years ago turning out to be measurement error.

If there were 200+ stars sending pulses like that, they would probably be an interstellar civilization that would need more than some sync pulses since atomic clocks are now as accurate to within a second during the entire age of the universe so they would not need time sync pulses, but they sure would need actual intelligible modulation of some kind, amplitude, frequency, phase, digital, SOMETHING more than just blip blip blip.

Which tells me more than likely it will be yet another measurement error situation that will correct itself and people will have a bit of egg on their faces just like the c+ neutrinos.
Jeffhans1
5 / 5 (7) Oct 20, 2016
When using an acronym, generally it is helpful to spell out the meaning before using it multiple times in an article. It usually makes sense to present it like "extra terrestrial intelligence (ETI)" initially before continuing to use ETI after that.
retrosurf
5 / 5 (5) Oct 20, 2016
That should be "Better rein in the ..."

It's kind of buggy-whip expression anyway. It's a wonder that it still survives.
cantdrive85
1.4 / 5 (9) Oct 20, 2016
The title of the article needs a slight adjustment;

'Either stars are strange, or astrophysicists are ignorant of plasma processes, or there are 234 aliens trying to contact us'
Captain Stumpy
4.6 / 5 (10) Oct 20, 2016
astrophysicists are ignorant of plasma processes
@cantread or think
this is technically called a FALSE CLAIM - or a statement about the real world refuted by the evidence
http://www.auburn...ion.html

considering:
you've yet to be able to produce any evidence that astrophysicists dont' know anything about plasma physics
AND
whereas a simple link to PPPL is enough to prove you wrong
AND
you've repeated this argument for years while never once being able to substantiate it without resorting to historical *opinion* that was proven wrong with the PPPL.gov link
THEN
what you're demonstrating is delusional fanatical behaviour that is no different than ISIS/ISIL or any other religious cult
gculpex
3.7 / 5 (3) Oct 20, 2016
I'll believe it when they get here.

Just knock'em out and steal their craft
Mimath224
5 / 5 (3) Oct 20, 2016
I agree with other comments here, except for 'can'tdo'. The article itself expresses doubt about aliens being responsible. If the signals are not errors and can be confirmed I think it just means that we still have much to learn.
Mark Thomas
3 / 5 (2) Oct 20, 2016
I have a feeling these astronomers have tenure, otherwise a couple professor spots are about to open up at Laval University. Maybe I will toss them my CV. My qualifications are I have a telescope, know what a Fourier Analysis is, and I know enough to not conclude every anomaly must be aliens. :-)
Protoplasmix
3.7 / 5 (3) Oct 20, 2016
They've already poured cold water on it, trotting out the old axiom that "Extraordinary claims require extraordinary evidence"
"Signals having the same period were found in only 234 stars [of 2.5 million spectra in the Sloan Digital Sky Survey]"* is really quite extraordinary by itself, natural origin or otherwise.

Additionally, "... only about 1% of the stars having a spectral type between F2 to K1 have the signal..."*

How many types of stars don't have continuous circumstellar habitable zones? Only O-type stars, right? So for an ETI origin, wouldn't that require saying that the F2 to K1 range must be necessary for the initial development of life? Else why no similar signals from stars with habitable zones outside the spectral range?

*quotes from pre-print: "Discovery of peculiar periodic spectral modulations in a small fraction of solar type stars"
Mimath224
5 / 5 (3) Oct 21, 2016
I'll believe it when they get here.

Just knock'em out and steal their craft

Ha! What if they use 'brain power' to operate their craft...do you think stealing their craft will do us much good?
javjav
1 / 5 (1) Oct 21, 2016
It does not look like a "hello" signal. For that one it would be much more significant to switch off the pulses for irregulars intervals, in numerical patterns demonstrating intelligence. If coming from ETI it must have a different purpose.
TheGhostofOtto1923
4.2 / 5 (5) Oct 21, 2016
astrophysicists are ignorant of plasma processes
That's not a FALSE CLAIM just an incredibly ignorant one.

"Lyman Strong Spitzer, Jr. (June 26, 1914 – March 31, 1997)[1] was an American theoretical physicist, astronomer and mountaineer. As a scientist, he carried out research into star formation, plasma physics, and in 1946, conceived the idea of telescopes operating in outer space. Spitzer invented the stellarator plasma device and is the namesake of NASA's Spitzer Space Telescope. As a mountaineer, he made the first ascent of Mount Thor, with David Morton."

-Of course I'm sure he didn't know plasma like EU moonies know plasma.
Arrowstone
3.3 / 5 (3) Oct 22, 2016
re: the old axiom that "Extraordinary claims require extraordinary evidence"

Actually all claims are equal when it comes to evidence. The "extraordinary" part is about paradigm defense, which is more of a religious thing.
Frosted Flake
3.7 / 5 (3) Oct 22, 2016
Interesting observation. Worth a close look. But let's first leap to the conclusion : If these are alien communication lasers, pause, and they are pointing them at us, pause, dot dot dot.

I don't think I've seen this movie. Sounds exciting.
tear88
3.7 / 5 (3) Oct 22, 2016
I'll believe it when they get here.

Just knock'em out and steal their craft

No wonder they don't land! They don't want anything to do with this planet of hoodlums. ;^)
gkam
1.7 / 5 (6) Oct 22, 2016
I am still waiting for signs of intelligent life on Earth.
Dark_Solar
3 / 5 (2) Oct 22, 2016
Yeah, I've got my skepticals on *bloop* but holy !@%$ and *^#*ing-a I've got my fingers crossed and I'm hoping. Don't really care how it turns out in the aftermath, I just want to live long enough to see first contact.
johnobrien
1 / 5 (1) Oct 24, 2016
Is it possible that orbiting planets are obscuring the light on a periodic basis, creating a pulse?

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