HD 139139 Incredibly Bizarre Star

[_DoubtingThomas]

"Astronomers Don't Know What to Make of This Incredibly Bizarre Star"
"He says one more possibility was left out of the paper, albeit an extremely unconventional one: an extraterrestrial mega-engineering project blocking the star's light."

https://www.scientificamerican.com/arti ... arre-star/

I am glad astronomers found another candidate. I hope we can find out soon.

[_Chap]

Don't get your hopes up.

" Similar speculations arose in 2015, when citizen scientists discovered a Kepler star with odd patterns and notified astronomer Tabetha Boyajian at Louisiana State University at Baton Rouge. The light dips in that case looked intriguing enough that astrophysicist Jason Wright of Pennsylvania State University organized a campaign to listen to the object, eventually nicknamed Tabby's star, for leaking radio transmissions. The undertaking ultimately turned up nothing unusual ... he considers it more likely astronomers will eventually settle on an explanation that does not involve intelligent extraterrestrials."

Read all about it:

The first astronomical explanation was that HD 139139 was surrounded by a bunch of planets, at least 14 and perhaps as many as 28—an astounding number, far greater than any known system. Based on their almost-identical light curves, these worlds would all be nearly the same size: slightly bigger than Earth.

The issue is that the extremely short duration of the dips in light suggested that any putative exoplanets would be passing quickly in front of the star, indicating close-in orbits. For none of them to repeat in the 80 days Kepler stared at the star strained credulity.

Another possibility was that a second body—a large planet or unseen star—was tugging gravitationally on the obscurants, causing them to sometimes hasten or delay their eclipsing and produce what looked like a random pattern. But such an object would also be pulling on the central star. After observing HD 139139 with ground-based telescopes, the team found no indication it was being tugged in this way.

The researchers looked into the idea that a planet might be disintegrating in front of the star, producing clouds of dust that would sometimes create dips and other times would not. Such cases have been seen in a small handful of systems, but in all of those examples astronomers were still able to identify the evaporating planet's orbital period.
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Finally, the team wondered if there were short-lived starspots (cooler patches analogous to sunspots) that suddenly appeared and disappeared on HD 139139's face—a situation nobody had really seen before. Vanderburg says this idea was considered mostly because he and his colleagues felt uncomfortable writing up a paper that did not include some kind of natural explanation.

He says one more possibility was left out of the paper, albeit an extremely unconventional one: an extraterrestrial mega-engineering project blocking the star's light. Similar speculations arose in 2015, when citizen scientists discovered a Kepler star with odd patterns and notified astronomer Tabetha Boyajian at Louisiana State University at Baton Rouge. The light dips in that case looked intriguing enough that astrophysicist Jason Wright of Pennsylvania State University organized a campaign to listen to the object, eventually nicknamed Tabby's star, for leaking radio transmissions. The undertaking ultimately turned up nothing unusual.

"When people in our community hear about something like this, the running joke is it might be aliens," Vanderburg says. The possibility crossed his mind, he adds, as the seemingly-random dips reminded him of the scene in the film Contact in which Jodie Foster's character begins hearing blips from outer space that trace out a prime number sequence.
The newly noticed star will certainly be added to the list of those investigated for signs of technological activity, Wright says. But he considers it more likely astronomers will eventually settle on an explanation that does not involve intelligent extraterrestrials.Boyajian agrees. "I think we have to consider all options before we go there," she says. "This is one of those systems where it's probably not going to be figured out without more data."

[_DoubtingThomas]

Don't get your hopes up.

But HD 139139 is currently the best candidate for alien mega-structures, but I admit it is not a good one.

[_moksha]

They were bound to find the Kolob ring-world sooner or later. We should be asking the Interpreter Foundation what to make of it (at least to help decode the many information bursts relating to the location of lost keys).

[_Chap]

Don't get your hopes up.

But HD 139139 is currently the best candidate for alien mega-structures, but I admit it is not a good one.

Precisely my point.

The best current candidate for an astronomical object representing large-scale construction by intelligent agencies of some kind is ... not a good candidate for an astronomical object representing large-scale construction by intelligent agencies of some kind.

So maybe we don't need to spend a lot of time talking about it? Let us know when there is some consensus that someone has discovered a good candidate for an astronomical object representing large-scale construction by intelligent agencies of some kind.

[_Themis]

Don't get your hopes up.

But HD 139139 is currently the best candidate for alien mega-structures, but I admit it is not a good one.

In some ways I would like to see some advanced species out there, but I also recognize the dangers to us. Would they be friendly? Would they share their knowledge? Would they share resources both groups would need in the galaxy? This star is only about 350 light years away. Maybe if they discover us at some point in the future they decide we are too close and too dangerous to let us live. In many ways I don't mind the idea that we are the only intelligent species in our galaxy.

[_DoubtingThomas]

Precisely my point.

The best current candidate for an astronomical object representing large-scale construction by intelligent agencies of some kind is ... not a good candidate for an astronomical object representing large-scale construction by intelligent agencies of some kind.

So maybe we don't need to spend a lot of time talking about it? Let us know when there is some consensus that someone has discovered a good candidate for an astronomical object representing large-scale construction by intelligent agencies of some kind.

It is not a good candidate because we don't have enough information, but we cannot rule out alien megastructures yet. So far there is not a good hypothesis that explains HD 139139.

[_Chap]

... we cannot rule out alien megastructures yet ...

True. And there are many other things that we can't rule out either. The lesson of astrophysics up to now is that there are many weird physical processes going on out there, processes that will really surprise us and take a long while to understand.

Do you remember pulsars?

Those Little Green Men keep on popping their heads up. But after a while the whack-a-mole astrophysicists knock them on the head.

The first pulsar was observed on November 28, 1967, by Jocelyn Bell Burnell and Antony Hewish.[3][4][5] They observed pulses separated by 1.33 seconds that originated from the same location in the sky, and kept to sidereal time. In looking for explanations for the pulses, the short period of the pulses eliminated most astrophysical sources of radiation, such as stars, and since the pulses followed sidereal time, it could not be human-made radio frequency interference.

When observations with another telescope confirmed the emission, it eliminated any sort of instrumental effects. At this point, Bell Burnell said of herself and Hewish that "we did not really believe that we had picked up signals from another civilization, but obviously the idea had crossed our minds and we had no proof that it was an entirely natural radio emission. It is an interesting problem—if one thinks one may have detected life elsewhere in the universe, how does one announce the results responsibly?"[6] Even so, they nicknamed the signal LGM-1, for "little green men" (a playful name for intelligent beings of extraterrestrial origin).

It was not until a second pulsating source was discovered in a different part of the sky that the "LGM hypothesis" was entirely abandoned.[7] Their pulsar was later dubbed CP 1919, and is now known by a number of designators including PSR 1919+21 and PSR J1921+2153. Although CP 1919 emits in radio wavelengths, pulsars have subsequently been found to emit in visible light, X-ray, and gamma ray wavelengths.[8]
The word "pulsar" is a portmanteau of 'pulsating' and 'quasar', and first appeared in print in 1968:

“An entirely novel kind of star came to light on Aug. 6 last year and was referred to, by astronomers, as LGM (Little Green Men). Now it is thought to be a novel type between a white dwarf and a neutron [star]. The name Pulsar is likely to be given to it. Dr. A. Hewish told me yesterday: '... I am sure that today every radio telescope is looking at the Pulsars.'[9]

[_DoubtingThomas]

Do you remember pulsars?

Those Little Green Men keep on popping their heads up. But after a while the whack-a-mole astrophysicists knock them on the head.

But it is still very likely that an advance civilization exists somewhere in the universe. According to a paper published in the International Journal of Astrobiology, "I propose a SETI-XNAV research program to test the hypothesis that this pulsar positioning system might be an instance of galactic-scale engineering by extraterrestrial beings."

Vidal, Clément. "Pulsar positioning system: a quest for evidence of extraterrestrial engineering." International Journal of Astrobiology (2017): 1-22.

https://youtu.be/pul9r0jfbug?t=45