[ExI] [Extropolis] Re: Google Alert - Tabby's Star

[Keith Henson]

On Mon, Aug 12, 2024 at 11:55 AM John Clark <johnkclark at gmail.com> wrote:
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> On Mon, Aug 12, 2024 at 12:19 PM Keith Henson <hkeithhenson at gmail.com> wrote:
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>>> >> 511 light years is next door astronomically speaking, there must be millions of stars like that in the Milky Way alone, but we can only see the closest ones; our solar system probably looked like that for millions of years during the time after the sun formed but before the planets did.
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>> > Kepler found only one star that acted this way.
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> I thought you said there were 24.

Later search, looking at stars near Tabby's Star.

>> > We could see this kind of blink for a very long distance.
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> Perhaps we could if we used our very largest telescopes to closely observe a particular star over a period of several months, but there are many billions of stars in the galaxy and there is no way to know beforehand which one is likely to exhibit this peculiar dimming. Telescope time for world-class instruments is very expensive.

Depends on the telescope.  Kepler looked at a some rather large number
of stars all at once.

> Also, at least in this solar system the planets started to form only a few million years after the sun did, and that was many billions of years ago. So there's only a very narrow window of opportunity for anybody to observe it. Thus it would be rare to find a star like Tabby, particularly if it was much further away than Tabby and thus much dimmer. And Tabby would need to be 450 times brighter to be visible with the naked eye.

Not sure of your reasoning here.

>> > a dust cloud in thermal equilibrium
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> Dust clouds are very complex systems and a lot of them are not in thermal equilibrium, the Boomerang nebula certainly isn't.
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>> > would be about 210 K and not the measured 65 K.
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> I don't know where you got that 65K figure. Maybe you've seen something recent that I haven't, but from what I know even the best measurements of the temperature of Tabby's dust cloud have huge error bars, they give a range of 200 to 500 K.

In any case, dust clouds just will not account for it because they
don't last very long.  The dust is blown out by light pressure like a
comet tail.

Eventually, the truth will be known.  If I am right, I will gain
status along with people like Jason Wright.  But as I say, I hope I am
wrong.

Keith

> John K Clark    See what's on my new list at  Extropolis
> rp1
>
>
>
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