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Tabby's Star Under Observation After Dimming Event Detected

posted by Fnord666 on Sunday May 21 2017, @03:54AM   
from the megastructures dept.

takyon writes:

Tabby's Star, speculated to be surrounded by a cloud of debris or alien megastructures, has dimmed yet again, causing multiple observatories to take notice:

Among the telescopes [Jason] Wright said researchers now hope to use to catch this dimming event in the act:

—The Green Bank Telescope in West Virginia, the world's largest fully steerable radio telescope
—The Automated Planet Finder at Lick Observatory near San Jose, Calif., a robotic optical telescope
—Both telescopes at the Keck Observatory in Hawaii, which operate in optical and near-infrared wavelengths
—The MMT Observatory in Arizona, an optical telescope
—NASA's Swift Gamma-Ray Burst Mission, which operates in gamma ray, x-ray, ultraviolet and optical wavelengths
—Las Cumbres Observatory, a worldwide network of robotic optical telescopes
—Fairborn Observatory in Arizona, which operates in optical wavelengths
—The Large Binocular Telescope in Arizona, which operates in optical and near-infrared wavelengths
—The Hobby–Eberly Telescope in Texas, an optical telescope

Also at The Verge.

One astronomer has proposed looking at the nearest 43 to 85 pulsars for megastructures (arXiv):

Osmanov estimates that the habitable zone around a relatively slowly-rotating pulsar (with a period of about half a second) would be on the order of 0.1 AU. According to his calculations, a ring-like megastructure that orbited a pulsar at this distance would emit temperatures on the order of 390 K (116.85 °C; 242.33 °F), which means that the megastructure would be visible in the IR band.

Previously: Mysterious Star May Be Orbited by Alien Megastructures
I'm STILL Not Sayin' Aliens. but This Star is Really Weird.
"Breakthrough Listen" to Search for Alien Radio Transmissions Near Tabby's Star
Non-Alien Explanation for Tabby's Star Dimming: It Ate a Planet

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Original Submission

• Pulsars? Pulsars? (Score: 1) by khallow on Sunday May 21 2017, @05:26AM (4 children)

  by khallow (3766) on Sunday May 21 2017, @05:26AM (#512893) Journal

  One astronomer has proposed looking at the nearest 43 to 85 pulsars for megastructures

  While there might be some considerable value to a pulsar environment that I can't figure out, it would be a bad place for fleshy beings such as myself to hang out (though rad-hardened organisms might do just fine). On the other hand, the light is great for searching for car keys.

• Re:Pulsars? Re:Pulsars? (Score: 2) by zocalo on Sunday May 21 2017, @10:49AM (3 children)

  by zocalo (302) on Sunday May 21 2017, @10:49AM (#512973)

  Actually, that could work out rather nicely. Pulsars are the remains of stars, so there would have been plenty of time for an advanced civilization to evolve before the star entered that stage of its life, which is a good start. Since the bulk of a pulsar's energy is emitted along a given axis, it might be possible to construct a Dyson structure with energy collection structures positioned along the axis of energy emission (the solar equator) and have the habitable / industrial areas of the structure at the solar poles. Whether the gravitational and radiation effects would be survivable at the necessary distances of the structure (both for the inhabitants and the structure itself), and how the inhabitants (or robotic ships) might transit the high-energy equatorial region for construction, maintenance work, etc. are likely to be problematic though.
  
  Still, you've got to wonder, given a civilization that is not only capable of engineering all of that but also surviving the transition of their star into a pulsar in the first place (a supernova, no less!), why they wouldn't have just figured out a way to relocate to another star system instead.

  --
  UNIX? They're not even circumcised! Savages!

  Parent

  • Re:Pulsars? Re:Pulsars? (Score: 2) by zocalo on Sunday May 21 2017, @10:57AM (2 children)

    by zocalo (302) on Sunday May 21 2017, @10:57AM (#512975)

    Oops! Just realised that the energy of a pulsar is along the magnetic axis, e.g. slightly offset from the poles, not along the "equator" - I'd been thinking of the accretion disk of a black hole. That actually makes it easier (relatively speaking), as the habitat area around the star would be in a ring away from the bulk of the energy emission, while energy collection could be closer to the perimeter of the emission zone, but not so far in that it would be blasted out of existance.

    --
    UNIX? They're not even circumcised! Savages!

    Parent

    • Re:Pulsars? Re:Pulsars? (Score: 1) by khallow on Sunday May 21 2017, @01:07PM (1 child)

      by khallow (3766) on Sunday May 21 2017, @01:07PM (#513001) Journal

      I bet the magnetic pole moves around and might even cross the rotational equator of the pulsar on a repetitive basis. It seems a challenging environment to say the least.

      Parent

      • Re:Pulsars? (Score: 2) by zocalo on Sunday May 21 2017, @03:02PM

        by zocalo (302) on Sunday May 21 2017, @03:02PM (#513032)

        Probably, but perhaps not by all that much. My impression is that a star's magnetic axis is pretty similar to a planet's like our own - it wobbles around and might even flip from time to time, but generally stays within a given zone. Given that a pulsar has such a high spin rate, so perhaps it's something like a gyroscope - the faster the rotation the more stable the axis is, and the less likely the magnetic poles are to move around? Alternatively, if any such changes don't occur on a short timescale, perhaps it would be possible for its creators to re-align a Dyson construct with the shifting poles as required, assuming a swarm, rather than a solid object, then they might even be able to get away with just re-aligning the energy collecting components.

        --
        UNIX? They're not even circumcised! Savages!

        Parent