Tabby's star: it's comets

[Murphy625]

I can't imagine how even a huge Jupiter sized planet, broken into smaller pieces, could possibly create enough material to cause a 22% dip...

But lets assume for a second it is planetary debris.. Shouldn't spectroscopy show some hint of an extra IR signature or some other color change upon the next dip?

And wouldn't the close orbit of these debris cause a much higher frequency of these dips? And at the opposite side, if the orbit was far and wide, and big enough to create such huge dips, we should see the IR signature yes?

I don't buy the planet hypothesis...

[not_Fritz_Argelander]

The absence of an IR excess means that the debris has to be in larger chunks. Dust sized debris would show as a constant IR excess. Excess IR would happen continuously not just during dips. But it does seem artificial for eating a planet to produce large chunks and no dust.

[not_Fritz_Argelander]

Dips caused by opaque bodies would not cause a color change BTW.

[Murphy625]

The absence of an IR excess means that the debris has to be in larger chunks. Dust sized debris would show as a constant IR excess. Excess IR would happen continuously not just during dips. But it does seem artificial for eating a planet to produce large chunks and no dust.

I agree if the chunks are large then no IR signature.. but then there wouldn't be enough material to make the star dip 22% either right?
And if the chunks were dust, and by some crazy fluke of the universe, spread out so perfect that they were able to cause a 22% dip, then we'd certainly see an IR signature yes?

Doesn't seem like either scenario works..

[MistrBadgr]

I think Tabby's star just has a big belly ache somehow!

[Murphy625]

I think Tabby's star just has a big belly ache somehow!

I think Fritz was on to something when he said it was something internal.. next to Aliens, an internal processes causing a quack star to act like a quack seems to be the most plausible.
Of course, I don't understand most of the explanations dealing with the internal processes.. and I'm also curious about how an internal process can cause a star to dip 22% without a corresponding change in its temperature color..

None of the external causes seem to add up....

[not_Fritz_Argelander]

I think Fritz was on to something when he said it was something internal.. next to Aliens, an internal processes causing a quack star to act like a quack seems to be the most plausible.
Of course, I don't understand most of the explanations dealing with the internal processes.. and I'm also curious about how an internal process can cause a star to dip 22% without a corresponding change in its temperature color..

If the pulsations are non radial then no change in color temperature is needed. All you need is a 22% change in the apparent size along the line of sight.

None of the external causes seem to add up....

There are problems. In difficulty with the model that barfs planetary debris after a heavy meal is how those debris would get lofted into such an eccentric orbit that the dips are asymmetric. The very asymmetry of the dips is quite pronounced and argues for pulsations of a nonracial sort. The only trick with nonracial pulsations is that the star would have to be only marginally unstable since there are gaps in the dips. But the thing of it is that Tabby's star is at the very edge of an instability strip. So I could see a starting a pulse then having it damp out rather than have a series of regular pulsations. Like a pendulum that has a lot of friction but gets a jolt occasionally. (In this case the jolt to cause the swing and the frictional forces to damp it are both internal.)

[MistrBadgr]

Is there any way to determine if this star has an excessive spin rate? It might end up with some sort of really twisted magnetic fields with significant sunspot activity at times....just a thought.
If it is a merger of two smaller stars whose cores have not merged completely, and had a fast spin, I can imagine all kinds of goofy things taking place.

[not_Fritz_Argelander]

Unfortunately that's hard. It depends on the angle the spin axis makes to the line of sight. If spin axis and line of sight are aligned there is no rotational broadening of spectral lines.

I'd expect that late stages of a merger of two stellar cores would exhibit a lot more chaotic behavior. Between dips the star is nearly constant.

[Murphy625]

Is there any way to determine if this star has an excessive spin rate? It might end up with some sort of really twisted magnetic fields with significant sunspot activity at times....just a thought.
If it is a merger of two smaller stars whose cores have not merged completely, and had a fast spin, I can imagine all kinds of goofy things taking place.

Per the wiki link:
https://en.wikipedia.org/wiki/KIC_8462852

It's rotates once every .87 days.. Compared to our own sun at 24 days it would seem like Tabby's star is zooming around like a top...