Cancer Posted May 31, 2011 Author Report Share Posted May 31, 2011 Re: Planets not orbiting stars [Necromantic update] In the 19 May 2011 issue of Nature, the two gravitational lensing groups (MOA and OGLE) published their results for ~500 planet-scale events seen in their observing programs of sightlines between us and the Galactic Bulge; thanks to Bazza for giving me a pointer to this in the Last Word NGD thread, because otherwise I would have missed it. The statistics are such that free-floating Jupiter-mass planets are approximately twice as numerous as main sequence stars and things that evolve from those. They don't do a lot of theoretical speculation about what that means for planet formation, though one gets the impression that this could be consistent with all the planets being formed around stars and being subsequently lost. Quote Link to comment Share on other sites More sharing options...
dmjalund Posted May 31, 2011 Report Share Posted May 31, 2011 Re: Planets not orbiting stars I suspect that smaller stars ar emore likely to lose planets than larger stars. On the other hand, what would a Ooort cloud object look like at the distances involved. Would they be able to associate it with a star? Quote Link to comment Share on other sites More sharing options...
Kraven Kor Posted May 31, 2011 Report Share Posted May 31, 2011 Re: Planets not orbiting stars I wonder what it would take to snag one of those puppies and put it into orbit around one's home star. I would think that would be counter-productive; my understanding is that planetary systems around stars have a somewhat delicate balance as it is. Adding another planetary mass could have serious consequences to the system as a whole. Quote Link to comment Share on other sites More sharing options...
Christopher Posted May 31, 2011 Report Share Posted May 31, 2011 Re: Planets not orbiting stars I would think that would be counter-productive; my understanding is that planetary systems around stars have a somewhat delicate balance as it is. Adding another planetary mass could have serious consequences to the system as a whole. True. For example: From what I heard and learned, the asteriod belt between earth and mars - that is basically a dead-borne planet. With the gravitational pull from earth and mars it just was ripped appart/never could really form. Plus, these things tend to fly like ... well, like planet. And that is even way worser than "flys like a brick/plate of lead" so better calculate really well... Quote Link to comment Share on other sites More sharing options...
Cancer Posted May 31, 2011 Author Report Share Posted May 31, 2011 Re: Planets not orbiting stars I suspect that smaller stars ar emore likely to lose planets than larger stars. On the other hand, what would a Ooort cloud object look like at the distances involved. Would they be able to associate it with a star? With the gravitational lensing technique, you get a handle on the mass of the lensing object (here, the planet) from how long the lensing event lasts. An object with the mass of any of the known Oort Cloud objects would make for very fast (and very weak) lensing events, probably undetectable unless you were staring at the star to be lensed already. There's been a couple of interestingly fast lensing events, but only of things around stars, IIRC. Quote Link to comment Share on other sites More sharing options...
dmjalund Posted May 31, 2011 Report Share Posted May 31, 2011 Re: Planets not orbiting stars True. For example: From what I heard and learned, the asteriod belt between earth and mars - that is basically a dead-borne planet. With the gravitational pull from earth and mars it just was ripped appart/never could really form. The asteroid belt is between Mars and Jupiter, and Jupiter is the planet mainly responsible for it being a non-planet. Quote Link to comment Share on other sites More sharing options...
Christopher Posted May 31, 2011 Report Share Posted May 31, 2011 Re: Planets not orbiting stars The asteroid belt is between Mars and Jupiter' date=' and Jupiter is the planet mainly responsible for it being a non-planet.[/quote'] Right, between the 4. and 5. Planet. My bad. Still show pretty good what a bad idea it is to bring stray planets back home. Quote Link to comment Share on other sites More sharing options...
McCoy Posted May 31, 2011 Report Share Posted May 31, 2011 Re: Planets not orbiting stars [Necromantic update] In the 19 May 2011 issue of Nature, the two gravitational lensing groups (MOA and OGLE) published their results for ~500 planet-scale events seen in their observing programs of sightlines between us and the Galactic Bulge; thanks to Bazza for giving me a pointer to this in the Last Word NGD thread, because otherwise I would have missed it. The statistics are such that free-floating Jupiter-mass planets are approximately twice as numerous as main sequence stars and things that evolve from those. They don't do a lot of theoretical speculation about what that means for planet formation, though one gets the impression that this could be consistent with all the planets being formed around stars and being subsequently lost. So, does this affect the Missing Mass problem? I'm thinking twice as many superJuipiters as mainstream stars, would show up in the second or third decimal place? Instead of 90% dark matter we would have 89.988%? From what I understand, current theory is that stars are not born in isolation but in clusters? If stars can be slingshoted out of a cluster to go their own way (as Sol apparently was and did), how much easier a planet? Quote Link to comment Share on other sites More sharing options...
Cancer Posted May 31, 2011 Author Report Share Posted May 31, 2011 Re: Planets not orbiting stars So' date=' does this affect the Missing Mass problem? I'm thinking twice as many superJuipiters as mainstream stars, would show up in the second or third decimal place? Instead of 90% dark matter we would have 89.988%?[/quote'] Yeah, you have the right of it there. Jupiter is about 1/1000 of a solar mass, so adding two of these for every star in the Galaxy makes for not a lot of mass. From what I understand, current theory is that stars are not born in isolation but in clusters? If stars can be slingshoted out of a cluster to go their own way (as Sol apparently was and did), how much easier a planet? Last time I looked into star formation theory there were suggestions that low-mass stars (and the Sun is in that bin) might not be formed in clusters to the extent more massive ones are, but that isn't that big a deal. Planetary systems have enough dynamical instability on their own that strictly from planetary interactions alone, ending up with lots of planets ejected is plausible; in principle, you should at minimum end up with approximately the same amount of mass retained in a system as gets ejected. That is, the biggest guy is likely to kick out (or eat) most of the lesser ones. It's pretty clear in our Solar System that the present Kuiper Belt is a tiny fraction of what it was at the end of planet formation, and while the evidence isn't so clear for the Main Belt asteroids, it wouldn't be too surprising if the same thing was true there as well. For whatever reason, the existing big planets in our S.S. are in a long-term resonantly stable configuration and will stay that way. How likely this is to happen for any newly formed planetary system is unclear (though any system we see will probably be in a long-term resonantly stable configuration because any system that isn't won't be seen as a multi-planet system for very long). Inverting that, it means that up to about half the planetary mass formed in a system could end up kicked out and floating free. Encounters between star systems (which should be rare, except maybe in the "nursery" cluster) or within a multiple-star system should be easily capable of ejecting all the planets. So the result of two Jupiter-class free-floating planets per main sequence star in the Galaxy isn't out of line with these ideas. Quote Link to comment Share on other sites More sharing options...
Sociotard Posted May 31, 2011 Report Share Posted May 31, 2011 Re: Planets not orbiting stars Related to this, there is a theory that dark matter could allow starless planets to heat up enough to have liquid water. (My BS Science detector goes off hard on this one, due to raw scale of speculation about a speculative type of matter and speculative type of stellar body, but it's still fun) http://www.physorg.com/news/2011-04-dark-starless-planets.html Quote Link to comment Share on other sites More sharing options...
ghost-angel Posted June 1, 2011 Report Share Posted June 1, 2011 Re: Planets not orbiting stars Yeah, but bad science can eqyal good gaming. Quote Link to comment Share on other sites More sharing options...
Tolan Posted June 13, 2011 Report Share Posted June 13, 2011 Re: Planets not orbiting stars Aint that the truth. As I believe was said earlier, planets flung out of their system by supernova stars always seemed a more likely way to produce rogue planets, but I suppose rogue gas giants could indeed form in a nebula, seeing as most proto-stars are gas giants at some point in their life. Interesting to think how they got ejected before they could go star, though... One does have to wonder what they're like in deep-space, though. Once they start to cool, they should be able to get pretty cold, barring subsequent recapture.I don't know if the science works, but would it be possible for there to be a planet that was so cold in deep space the surface or near-surface was liquid gas? Though I suppose it would have to contend with internal heating from pressure. Quite interesting. -Tolan Quote Link to comment Share on other sites More sharing options...
Christopher Posted June 13, 2011 Report Share Posted June 13, 2011 Re: Planets not orbiting stars As I believe was said earlier' date=' planets flung out of their system by supernova stars always seemed a more likely way to produce rogue planets, but I suppose rogue gas giants could indeed form in a nebula, seeing as most proto-stars are gas giants at some point in their life.[/quote'] Not some, all of them. The sequence seems to be: Gas Giant Brown Dwarf Real Star The only difference between the three catergories is mass (a lot of mass however). Quote Link to comment Share on other sites More sharing options...
AmadanNaBriona Posted June 13, 2011 Report Share Posted June 13, 2011 Re: Planets not orbiting stars This reminds me of a subject I saw was up for a couple of panel discussions at Baycon, to whit: Habitability of red dwarf systems Quote Link to comment Share on other sites More sharing options...
L. Marcus Posted June 13, 2011 Report Share Posted June 13, 2011 Re: Planets not orbiting stars ... Oooo! Never thought of that! Those'd be pretty gloomy planets, though. Perpetual red-light districts. Quote Link to comment Share on other sites More sharing options...
etherio Posted June 13, 2011 Report Share Posted June 13, 2011 Re: Planets not orbiting stars This reminds me of a subject I saw was up for a couple of panel discussions at Baycon, to whit: Habitability of red dwarf systems MMMMMmmmm...Baycon.... Quote Link to comment Share on other sites More sharing options...
feralucce Posted June 16, 2011 Report Share Posted June 16, 2011 Re: Planets not orbiting stars Two options are likely, according to the text books we have over here in the astrophysics department... 1) born in stellar nurseries, not enough mass to ignite the fusion process and 2) (more likely) a near pass with another stellar mass object moving at a fast velocity pulled the planets away from the mother stat and left them lost out there in the black Quote Link to comment Share on other sites More sharing options...
Christopher Posted June 16, 2011 Report Share Posted June 16, 2011 Re: Planets not orbiting stars 1) born in stellar nurseries, not enough mass to ignite the fusion process and 2) (more likely) a near pass with another stellar mass object moving at a fast velocity pulled the planets away from the mother stat and left them lost out there in the black How about a combination? They were forming to be stars, but where expelled for the gas cloud before they could get enough mass/unite to start fusion? Quote Link to comment Share on other sites More sharing options...
Drhoz Posted June 16, 2011 Report Share Posted June 16, 2011 Re: Planets not orbiting stars Two options are likely, according to the text books we have over here in the astrophysics department... 1) born in stellar nurseries, not enough mass to ignite the fusion process and 2) (more likely) a near pass with another stellar mass object moving at a fast velocity pulled the planets away from the mother stat and left them lost out there in the black actually, interacting with other protoplanets is enough to kick them out of the system - the other planet moves in closer to its sun, and we end up with a Hot Jupiter and a rogue. Quote Link to comment Share on other sites More sharing options...
The Weapon Posted June 16, 2011 Report Share Posted June 16, 2011 Re: Planets not orbiting stars I'd always presumed that rogue planets came from systems that went supernova. Like any other object in space, large gravity fields could capture them. The problem being the very, very low probability of them wandering into said gravity fields. Actually most free planets were probably originally normal planets that got thrown out of their solar system when another solar system [ EDIT actually most were probably thown out by other planets or protoplanets as Drhoz said ]went through. I don't know how two of them got together though. Maybe they were each in a different solar system and the two systems passed through each other. They were close enough to attract one another when they were being thrown out. Quote Link to comment Share on other sites More sharing options...
feralucce Posted June 17, 2011 Report Share Posted June 17, 2011 Re: Planets not orbiting stars While it is possible for planetary gravitation can be enough to throw planets out of a system... The size of planets described makes that highly unlikely, as they are the ones who do the shoving. It is far more likely, if they were part of a system originally, that something much more massive was responsible... Especially if they are in orbit around each other... That indicates they came out into the black together... And if not, the odds are (no pun intended) astronomical. Considering the mass of the big one, the possibility of both options bein in place is statistically significant as that planet is nearing the breaking point between remaining a planet and HAVING to ignite due to pressure. As for dark matter... I hate to rain on anyone's parade, but according to all the information I can find, it seems that curreent theories state that dark matter, like super strings are an eleven diminutional construct that does not extend into the l,w,h dimensionality, therefor only contributing mass and gravity. I could be misreading it all... Personally, I am thinking of taking a vacation after reading some of this as it hurts the brain... Even in someone who knows the math... So I think I will go be a non-event mass with a quantum probability if zero for the next 8-10 hours... Rep to the person that recognizes my last refence WITHOUT looking it up! Quote Link to comment Share on other sites More sharing options...
AmadanNaBriona Posted June 17, 2011 Report Share Posted June 17, 2011 Re: Planets not orbiting stars Personally, I am thinking of taking a vacation after reading some of this as it hurts the brain... Even in someone who knows the math... So I think I will go be a non-event mass with a quantum probability if zero for the next 8-10 hours... Rep to the person that recognizes my last refence WITHOUT looking it up! Trying to save up your spare time like a certain 2nd Technician? Quote Link to comment Share on other sites More sharing options...
feralucce Posted June 17, 2011 Report Share Posted June 17, 2011 Re: Planets not orbiting stars Repped! Quote Link to comment Share on other sites More sharing options...
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