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Posted

SPECULATION: As stars die, they go through major fluctuations in their gravitational strength. This would enable planets in orbit around those stars to escape - particularly the outermost planets. Escaping their parent stars, they would eventually become undetectable through reflected light.

 

QUESTION: Would it be possible to detect these planets from infrared signals if they had internal heating?

Posted

SPECULATION: As stars die, they go through major fluctuations in their gravitational strength. This would enable planets in orbit around those stars to escape - particularly the outermost planets. Escaping their parent stars, they would eventually become undetectable through reflected light.

 

QUESTION: Would it be possible to detect these planets from infrared signals if they had internal heating?

 

 

Yes, in fact they have been...

 

http://en.wikipedia.org/wiki/Rogue_planet

Posted

SPECULATION: As stars die, they go through major fluctuations in their gravitational strength. This would enable planets in orbit around those stars to escape - particularly the outermost planets. Escaping their parent stars, they would eventually become undetectable through reflected light.

 

QUESTION: Would it be possible to detect these planets from infrared signals if they had internal heating?

Where did you get the idea that stars would fluctuate gravitationally as they die? This could only be a result of mass fluctuation. Dying stars would change mass very slowly unless they explode (supernovae).

Posted

Where did you get the idea that stars would fluctuate gravitationally as they die? This could only be a result of mass fluctuation. Dying stars would change mass very slowly unless they explode (supernovae).

". . . unless they explode.'

It was my understanding that stars contract and expand as they go through their final phases prior to final detonation. That has to play havoc with the stability of orbiting planets. . . some are bound to break free.

Posted

The volume of an object has essentially no impact on it's gravitational pull unless it expands to the point that you are inside of it.

 

If a star has 1 solar mass with a center of gravity 1 AU from a planet, the gravity felt by that planet will not change regardless of what the star does unless it changes one of those two qualities. Expansion and contraction will not change the mass nor the center of gravity, so unless the star expands to engulf the planet, the planet probably won't notice anything different about the gravitational pull it experiences.

Posted

The volume of an object has essentially no impact on it's gravitational pull unless it expands to the point that you are inside of it.

 

If a star has 1 solar mass with a center of gravity 1 AU from a planet, the gravity felt by that planet will not change regardless of what the star does unless it changes one of those two qualities. Expansion and contraction will not change the mass nor the center of gravity, so unless the star expands to engulf the planet, the planet probably won't notice anything different about the gravitational pull it experiences.

Don't stars blast substantial mass away from their surfaces when they are expanding?

Posted

Yes, near the end of its' life the sun will lose much mass and the outer planets will continue at the same speed which may cause them to spiral away from the sun. They could fly off into interstallar space.

 

http://en.wikipedia.org/wiki/Sun#After_core_hydrogen_exhaustion

 

"When the helium is exhausted, the Sun will repeat the expansion it followed when the hydrogen in the core was exhausted, except that this time it all happens faster, and the Sun becomes larger and more luminous. This is the asymptotic giant branch (AGB) phase, and the Sun is alternately burning hydrogen in a shell or helium in a deeper shell. After about 20 million years on the early AGB, the Sun becomes increasingly unstable, with rapid mass loss and thermal pulses that increase the size and luminosity for a few hundred years every 100,000 years or so. The thermal pulses become larger each time, with the later pulses pushing the luminosity to as much as 5,000 times the current level and the radius to over 1 AU.[109] Models vary depending on the rate and timing of mass loss. Models that have higher mass loss on the RGB produce smaller, less luminous stars at the tip of the AGB, perhaps only 2,000 times the luminosity and less than 200 times the radius.[108] For the Sun, four thermal pulses are predicted before it completely loses its outer envelope and starts to make a planetary nebula. By the end of that phase - lasting approximately 500,000 years - the Sun will only have about half of its current mass."

Posted

Yes, near the end of its' life the sun will lose much mass and the outer planets will continue at the same speed which may cause them to spiral away from the sun. They could fly off into interstallar space.

 

http://en.wikipedia.org/wiki/Sun#After_core_hydrogen_exhaustion

 

"When the helium is exhausted, the Sun will repeat the expansion it followed when the hydrogen in the core was exhausted, except that this time it all happens faster, and the Sun becomes larger and more luminous. This is the asymptotic giant branch (AGB) phase, and the Sun is alternately burning hydrogen in a shell or helium in a deeper shell. After about 20 million years on the early AGB, the Sun becomes increasingly unstable, with rapid mass loss and thermal pulses that increase the size and luminosity for a few hundred years every 100,000 years or so. The thermal pulses become larger each time, with the later pulses pushing the luminosity to as much as 5,000 times the current level and the radius to over 1 AU.[109] Models vary depending on the rate and timing of mass loss. Models that have higher mass loss on the RGB produce smaller, less luminous stars at the tip of the AGB, perhaps only 2,000 times the luminosity and less than 200 times the radius.[108] For the Sun, four thermal pulses are predicted before it completely loses its outer envelope and starts to make a planetary nebula. By the end of that phase - lasting approximately 500,000 years - the Sun will only have about half of its current mass."

 

O.k. Thanks!

It would seem this supports the basic notion of planets escaping stars as they go through this process. . . It would further seem that this has happened many millions of times in cosmic history, which further suggests there are millions of free-floating planets out there.

 

Now, what I'm wondering is how to detect them. Reflected light is not an option, so I am wondering if internal heat would be detectable at interstellar distances for planets like Earth or Mercury or even Jupiter. . .

Posted (edited)

"Now, what I'm wondering is how to detect them. Reflected light is not an option, so I am wondering if internal heat would be detectable at interstellar distances for planets like Earth or Mercury or even Jupiter."

 

That is an interesting question.

 

Here is what I found on Wiki under "Rogue Planets".

 

"When a planetary-sized object passes in front of a background star, its gravitational field causes a momentary increase in the visible brightness of the background star. This is known as microlensing. Astrophysicist Takahiro Sumi of Osaka University in Japan and colleagues, who form the Microlensing Observations in Astrophysics (MOA) and the Optical Gravitational Lensing Experiment (OGLE) collaborations, carried out a study of microlensing which they published in 2011. They observed 50 million stars in our galaxy using the 1.8 meter MOA-II telescope at New Zealand's Mount John Observatory and the 1.3 meter University of Warsaw telescope at Chile's Las Campanas Observatory. They found 474 incidents of microlensing, ten of which were brief enough to be planets of around Jupiter's size with no associated star in the immediate vicinity. The researchers estimated from their observations that there are nearly two free-floaters for every star in our galaxy.[7][8][9] Other estimations suggest a much larger number, up to 100,000 times more free-floating planets than stars in our Milky Way.[10]"

 

It is calculated that for an Earth-sized object at a kilobar hydrogen atmospheric pressures in which a convective gas adiabat has formed, geothermal energy from residual core radioisotope decay will be sufficient to heat the surface to temperatures above the melting point of water.[11] Thus, it is proposed that interstellar planetary bodies with extensive liquid-water oceans may exist. It is further suggested that these planets are likely to remain geologically active for long periods, providing a geodynamo-created protective magnetosphere and possible sea floor volcanism which could provide an energy source for life.[11] The author admits these bodies would be difficult to detect due to the intrinsically weak thermal microwave radiation emissions emanating from the lower reaches of the atmosphere, although later research suggests[13] that reflected solar radiation and far-IR thermal emissions may be detectable if one were to pass within 1000 AU of Earth.

 

http://en.wikipedia.org/wiki/Rogue_planet

Edited by Airbrush
Posted (edited)

So we finally get back to what i posted in post #2?

 

Sorry I didn't notice you posted the link already. I usually don't go to links unless the person who posted it gives an interesting passage FROM the link. Thanks.

Edited by Airbrush
Posted (edited)
www.thefreedictionary.com/rogue

 

 

An unprincipled, deceitful, and unreliable person; a scoundrel or rascal. 2. One who is playfully mischievous; a scamp. 3. A wandering beggar; a vagrant. 4. A vicious and solitary animal, especially an elephant that has separated itself from its herd.

 

Sucks to be that planet. Could you ever live down that bad rep. WAIT! Don't let it get near VENUS! ohmy.png

Edited by arc
Posted (edited)

www.thefreedictionary.com/rogue

 

 

 

 

 

 

 

 

An unprincipled, deceitful, and unreliable person; a scoundrel or rascal. 2. One who is playfully mischievous; a scamp. 3. A wandering beggar; a vagrant. 4.[/size] A vicious and solitary animal, especially an elephant that has separated itself from its herd. [/size]

 

Sucks to be that planet. Could you ever live down that bad rep. WAIT! Don't let it get near VENUS! ohmy.png[/size] [/size]

ii I think it's very interesting that a rogue planet could have a hydrogen atmosphere and water oceans due to internal heat and greenhouse effect of hydrogen... makes for some interesting bio chemistry speculation... VENUS IS A SLUT...evil.gif Edited by Moontanman
Posted

ii I think it's very interesting that a rouge planet could have a hydrogen atmosphere and water oceans due to internal heat and greenhouse effect of hydrogen... makes for some interesting bio chemistry speculation... VENUS IS A SLUT...evil.gif

 

Alright then, don't let it get near Uranus.laugh.png

Posted

"The scientists have proposed that these life-bearing planets originated in the early Universe within a few million years of the Big Bang, and that they make up most of the so-called "missing mass" of galaxies."

 

Link courtesy of Moontanman:

 

http://www.sciencedaily.com/releases/2012/05/120510100217.htm

 

How much of this missing mass is considered dark matter?

There is strong evidence (based on the amount of H1, H2, and He4 in the universe) that the amount of baryonic matter in the unverse is as been described (~ 4.5%). These free floating planets (if they exist) can't be made up mostly of baryonic matter.

Also dark matter distribution is mostly around galaxies. Dark matter is estimated at ~ 23%.

Posted

If there are trans-stellar planets, and I can see no reason why they shouldn't exist, I would imagine many if not most of them would be the result of gravitational close-encounters between passing star systems. Just a thought.

Posted

ii I think it's very interesting that a rouge planet could have a hydrogen atmosphere and water oceans due to internal heat and greenhouse effect of hydrogen... makes for some interesting bio chemistry speculation... VENUS IS A SLUT...evil.gif

'. . .rouge planet'? Planet's wearing lipstick?

Posted

'. . .rouge planet'? Planet's wearing lipstick?

 

Trans-Stellar rouge planet wearing lipstick. Whatever you do, don't Google THAT! blink.png

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