KIC 8462852 Observations |
KIC 8462852 Observations |
Oct 15 2015, 04:45 PM
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#1
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Senior Member Group: Members Posts: 2530 Joined: 20-April 05 Member No.: 321 |
Kepler found one very, very strange case:
http://www.theatlantic.com/science/archive...-galaxy/410023/ In a nutshell, while Kepler was observing it, the star (larger and brighter than the Sun) exhibited four dimming events that took place at irregular intervals, blocked a lot more light than a Jupiter-sized planet would block, and had a "shape" that varied in all four cases and did not resemble a planet. This case is attracting some wild speculation… in fact, it is seemingly certain that something wild must be going on; it's just a matter of which wild scenario is the correct one. If I had to throw my hat in the ring, I'd guess that a distant collision and breakup has placed big swarms of matter into a very long-period orbit. But there's no hypothesis that's been offered that doesn't seem problematic. |
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Jan 23 2016, 05:29 PM
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#2
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Junior Member Group: Members Posts: 68 Joined: 27-March 15 Member No.: 7426 |
KIC 8462852 is reportedly being watched for another instance of dimming. It was proposed to then analyze the light spectroscopically. It was indicated that this could determine if it was dust, or larger objects that were responsible for the dimming.
Dr. Schaefer's findings now seem to show that the star is already being substantially dimmed on a continuing basis. Wouldn't the spectroscopic work already done, which failed to find excess dust, indicate that larger objects cause the dimming? But what sort of larger objects? Dr. Schaefer's work seems to call the cometary explanation into very serious doubt. Disrupted planets were already doubted, due to the absence of dust. Dimming of 15 and 22 percent suggest objects on the order of 500,000 to 700,000 miles in diameter. Single objects on this scale would appear to be stars, but no other conspicuously shining stars have been found very near KIC 8462852. |
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Jan 25 2016, 03:53 PM
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#3
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Member Group: Members Posts: 684 Joined: 24-July 15 Member No.: 7619 |
KIC 8462852 is reportedly being watched for another instance of dimming. It was proposed to then analyze the light spectroscopically. It was indicated that this could determine if it was dust, or larger objects that were responsible for the dimming. ... Wouldn't the spectroscopic work already done, which failed to find excess dust, indicate that larger objects cause the dimming? But what sort of larger objects? ... I believe they thought "inner planet smash" and looked for excess infrared radiation, didn't see it, and interpreted the lack of signal as the lack of hot dusty debris and concluded no inner planet collisions. Next, hypothesis for dimming, without infrared, was a comet swarm on an elliptical orbit. That doesn't seem to fit, it requires a staggering number of comets. So, it may seem that we are left with a single large object as the 3rd choice. However, does a lack of IR actually rule out large inner solar system collision? We consider that additional cold dust further out might blocking starlight, how about blocking IR? So, what if both #1 and #2 happened? Inner planet collision and comet dust that blocks that IR? 1) What are the chances that there is a planetary system around Tabby's star. Pretty good. 2) What are the chances that planets around Tabby's star could shift orbits? Given the large percentage of hot Jupiters and hot Neptunes that have been observed, pretty good. 3) What are the chances that shifting planets create dust and comet redistribution? Pretty good. We know/suspect our solar system has been shuffled at some point, comets and asteroids and KBOs all shifted around. The recent Planet 9 paper's authors did a prior paper about nice model / jumping Jupiter scenario. Their simulations showed that for a sun-sized star, the gas giants generally eject comets or planets from a solar system, while the ice giants generally scatter them around the solar system. So, here's a mechanism to consider. Tabby's star is a sun-sized solar system, similar amount of material, similar snow line. It develops with ice giants but no gas giants, then it experiences planetary migration. Because it does not have gas giants to scatter comets out to oort distances as long period comets, Tabby's Star ends up with a massive kuiper belt, and we are seeing either a massive comet shower, or actual planetary scattering. So, my questions What is the expected IR signal from an inner solar system disrupted rocky planet? What level of comet dust would be necessary to absorb that IR signal? |
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