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Post by jandl100 on Dec 22, 2016 7:12:52 GMT
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Post by MartinT on Dec 22, 2016 10:09:41 GMT
Good call, better than the aliens theory as they say. However, a 22% dip in light output would suggest a very unstable star. Glad we're not too close to it!
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Post by jandl100 on Dec 22, 2016 10:16:34 GMT
Some variable stars change in power output by x5 on a regular cycle just a few hours long.
Now that would be a challenge for any life on orbiting planets!
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Post by MartinT on Dec 22, 2016 11:38:21 GMT
Is that variable due to spin, Jerry, or some result of internal processes?
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Post by jandl100 on Dec 22, 2016 16:40:41 GMT
Internal processes - from Wiki ... Dynamics of the pulsation The accepted explanation for the pulsation of Cepheids is called the Eddington valve,[44] or κ-mechanism, where the Greek letter κ (kappa) denotes gas opacity. Helium is the gas thought to be most active in the process. Doubly ionized helium (helium whose atoms are missing both electrons) is more opaque than singly ionized helium. The more helium is heated, the more ionized it becomes. At the dimmest part of a Cepheid's cycle, the ionized gas in the outer layers of the star is opaque, and so is heated by the star's radiation, and due to the increased temperature, begins to expand. As it expands, it cools, and so becomes less ionized and therefore more transparent, allowing the radiation to escape. Then the expansion stops, and reverses due to the star's gravitational attraction. The process then repeats. en.wikipedia.org/wiki/Cepheid_variableThis gives a very regular variability which is dependent on the star's precise luminosity - so regular is it that these types of variable star can be used as "standard candles" to determine astronomical distances. |
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Post by MartinT on Dec 22, 2016 18:27:01 GMT
Interesting - thanks.
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Post by jandl100 on Jan 12, 2017 7:31:48 GMT
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Post by MartinT on Jan 12, 2017 8:02:26 GMT
It must be fascinating receiving the data and hypothesising as to what causes it...
"The researchers hypothesize that a planet recently plunged into KIC 8462852. The gravitational energy produced by the collision would have boosted the star’s normal nuclear energy production, causing it to brighten rapidly and then slowly decay over time. If this idea is correct, then we happen to be observing Tabby’s star as it returns to its normal level of luminosity."
All this from a pinpoint of light!
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Post by jandl100 on Jan 12, 2017 8:15:31 GMT
That pinpoint of light provides quite a lot of information!
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Post by Chris on Jan 15, 2017 9:40:36 GMT
Still think there's other much more intelligent than us life out there.
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Deleted
Deleted Member
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Post by Deleted on Jan 15, 2017 10:14:00 GMT
Still think there's other much more intelligent than us life out there. What, than TAS? Never!  Actually i agree. Probbaly lots of intelligent life out there IMO. |
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Post by MartinT on Jan 16, 2017 8:00:41 GMT
The odds against our being the only species are minuscule, effectively zero.
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Post by jandl100 on Jan 16, 2017 8:12:19 GMT
I agree - unless we are in a simulation to evaluate the consequences of having a single point of life in an otherwise lifeless universe.  |
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Post by MartinT on Jan 16, 2017 8:40:28 GMT
Create New Document, size: vast!
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Post by jandl100 on Jan 16, 2017 17:44:22 GMT
This is an interesting article io9.gizmodo.com/jupiter-may-have-destroyed-the-solar-systems-first-plan-1693169374It looks like the bar for Earth-like habitable planets around other stars may have been raised by a considerable margin. The theory is that it took a low probability pairing of migrating Jupiter and Saturn to create the solar system as we now know it. The Mercury/Venus/Earth/Mars planets may be low probability 2nd generation objects. |
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Post by MartinT on Jan 16, 2017 23:17:52 GMT
Bad news for the future generation ships.
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Post by jandl100 on Jan 17, 2017 7:20:15 GMT
Well, the science/technology bods are already planning 0.2c interstellar probes (laser launched micro-tech) - I'm sure that speed can be boosted significantly. So it is within the bounds of foreseeable tech to suss out nearby star systems before the generation ships are launched. But yes, it might be a very long journey if Earth mk2 is being sought!
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Post by MartinT on Jan 17, 2017 8:45:28 GMT
They're going to have to solve the danger from even micro-dust impacts at that speed. Interesting concept used in the film Passengers for shielding the ship from impacts.
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... but a new astronomical phenomenon related to stellar interiors.
