The Most Mysterious Star in the Galaxy

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Profile LynnProject Donor
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Message 1885610 - Posted: 23 Aug 2017, 16:28:31 UTC - in response to Message 1873875.  

This article could explain some things..

The “alien megastructure” star that has been puzzling us for the past few years might have a more ordinary explanation: an orbiting Saturn-like planet, complete with wobbling rings. In 2015, a group led by Tabetha Boyajian, then of Yale University, found that a star called KIC 8462852 had dimmed several times over a few years in a way they couldn’t explain. The star had been observed by the Kepler space telescope between 2009 and 2013 as it hunted for exoplanets by staring at a patch of sky. When a planet passes in front of a star, an event called a transit, the light intensity dips slightly and then returns to normal. But KIC 8462852, since dubbed Tabby’s star, didn’t behave that way, with the ...

https://www.newscientist.com/article/2144869-alien-megastructure-star-may-host-saturn-like-exoplanet/
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Message 1885615 - Posted: 23 Aug 2017, 16:46:32 UTC

might have a more ordinary explanation: an orbiting Saturn-like planet,

More than likely.
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Message 1885634 - Posted: 23 Aug 2017, 17:58:52 UTC - in response to Message 1873875.  

Suppose a planet could maintain immense rings, large enough to block out up to 22 percent of the star's light, which is what would be required in the case of KIC 84622852. The author specifies that this would be a 'close in' planet. This leaves us with the unanswered question: Where is the excess infrared radiation that such a planet, and especially its rings, would be expected to create? The material is close enough to the star to receive substantial stellar radiation, and reradiate it in the infrared. No such excess infrared has been observed at Tabby's Star, and it has been looked for with considerable care.
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Message 1885659 - Posted: 23 Aug 2017, 20:45:52 UTC - in response to Message 1885634.  

A planet that big and close to its parent star should also impart a wobble in the star's orbit, leading to a Doppler shift in the star's light. I'm not aware that any such Doppler shift has been detected for KIC8462852.
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Message 1889105 - Posted: 10 Sep 2017, 18:17:35 UTC

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Message 1889143 - Posted: 10 Sep 2017, 23:59:39 UTC
Last modified: 11 Sep 2017, 0:05:37 UTC

This is the conclusion of one scientist and his team. Others have expressed doubt that this paper proves that only dust is a factor in the star's dimming.

While dust is obviously present, this may not be the whole story. One can see a good deal of dust at a construction site. This does not establish that nothing larger is being constructed.

The problem was long framed as a binary one, either it was merely dust, and so natural, or it was only large structures, obviously artificial. It appears that we need to look at the problem with a bit more finesse than that.

It may be that the 'dust only' hypothesis will eventually be confirmed by others, and become generally accepted. Until then, it is merely one hypothesis among many.
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Message 1893579 - Posted: 6 Oct 2017, 6:57:46 UTC - in response to Message 1889143.  

Reasonable explanation?



Mysterious Dimming of Tabby's Star May Be Caused by Dust


One of the most mysterious stellar objects may be revealing some of its secrets at last.

Called KIC 8462852, also known as Boyajian's Star, or Tabby's Star, the object has experienced unusual dips in brightness -- NASA's Kepler space telescope even observed dimming of up to 20 percent over a matter of days. In addition, the star has had much subtler but longer-term enigmatic dimming trends, with one continuing today. None of this behavior is expected for normal stars slightly more massive than the Sun. Speculations have included the idea that the star swallowed a planet that it is unstable, and a more imaginative theory involves a giant contraption or "megastructure" built by an advanced civilization, which could be harvesting energy from the star and causing its brightness to decrease.
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Message 1893911 - Posted: 7 Oct 2017, 20:02:53 UTC - in response to Message 1893579.  

Researchers found less dimming in the infrared light from the star than in its ultraviolet light. Any object larger than dust particles would dim all wavelengths of light equally when passing in front of Tabby's Star.

"This pretty much rules out the alien megastructure theory, as that could not explain the wavelength-dependent dimming," said Huan Meng, at the University of Arizona, Tucson

That makes sense to me.
The mind is a weird and mysterious place
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Message 1893923 - Posted: 7 Oct 2017, 20:43:46 UTC
Last modified: 7 Oct 2017, 20:45:22 UTC

The authors of the paper are careful to point out that their conclusions apply only to the long term, gradual dimming of the star, *not* to the intermittent dips in light output of up to 22 percent. It's possible that the former is the dust, associated with construction sites, even on Earth, and that the intermittent dips are caused by what is being constructed.
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Message 1894106 - Posted: 8 Oct 2017, 16:08:54 UTC

https://www.scientificamerican.com/article/new-observations-deepen-mystery-of-ldquo-alien-megastructure-rdquo-star/?utm_source=newsletter&utm_medium=email&utm_campaign=daily-digest&utm_content=link&utm_term=2017-10-05_featured-this-week

New Observations Deepen Mystery of “Alien Megastructure”
Star Orbiting dust could explain some
but not all of the star’s bizarre behavior

You can read the Simon et al. study for free at the online

https://arxiv.org/pdf/1708.07822.pdf

Alien Megastructure' Star Being Investigated By UC Berkeley | Video

The new study does not solve all of KIC 8462852's mysteries, however. For example, it does not address the short-term 20 percent brightness dips, which were detected by NASA's planet-hunting Kepler space telescope. (Kepler is now observing a different part of the sky during its K2 extended mission and will not follow up on Tabby's star for the forseeable future.)
And a different study—led by Joshua Simon of the Observatories of the Carnegie Institution for Science in Pasadena, California—just found that Tabby's star experienced two brightening spells over the past 11 years. (Simon and his colleagues also determined that the star has dimmed by about 1.5 percent from February 2015 to now.)
"Up until this work, we had thought that the star's changes in brightness were only occurring in one direction—dimming," Simon said in a statement. "The realization that the star sometimes gets brighter in addition to periods of dimming is incompatible with most hypotheses to explain its weird behavior."

Strange brightness dips

KIC 8462852, which lies about 1,500 light-years from Earth, has generated a great deal of intrigue and speculation since 2015. That year, a team led by astronomer Tabetha Boyajian (hence the star's nicknames) reported that KIC 8462852 had dimmed dramatically several times over the past half-decade or so, once by 22 percent
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Message boards : SETI@home Science : The Most Mysterious Star in the Galaxy


 
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