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Odd Planet Confuses Scientists
eldavojohn writes "While there's been a lot of debate about what is a planet, there is a recent discovery that has scientists even more confused. COROT (COnvection ROtation and planetary Transits) spotted an object that appears to be the size of Jupiter yet is 21.6 times more massive ... and orbits its star in a mere four days and six hours. Now, the other piece of the puzzle is that the star it orbits is more massive and only slightly larger than our Sun. But they can't describe this thing orbiting it. So far they think it is more likely to be a 'failed star' but have settled with 'member of a new-found family of very massive planets that encircle stars more massive than the sun' to describe it accurately."
... but that's no moon.
Don't rush me, Sonny. You rush a miracle man, you get rotten miracles.
One thing I've wondered about: Does orbital mechanics lead to fractal planetary arrangements?
If so, binary stars and star/gas-giant planetary systems are just points in a continuum.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
"the size of Jupiter yet 21.6 times more massive.. and orbits its star in a mere four days and six hours."
That's New Year roughly twice a week, by Jove.
Party on ; ).
"Kill 'em all and let Root sort 'em out"
...before long astrophysicists will have more words for things that orbit other things than the Inuit have for snow.
If it is twice as dense as lead, what is it made of?
This sig is definitive. Reality is frequently inaccurate.
MOANFFOVMPTESMMTTS is not really the best acronym for anyone. Did they blow their acronymic wad with WIMPs and MACHOs and RAMBOs and whatnot?
This is what it would be like, if the majority of people were athiests.
SNIP
Scary, isn't it?
Terrifying. The idea that such tripe could be considered as "wisdom" by anybody, no matter how anonymously cowardly. This steaming pile of idiocy is an excellent example of the logical fallacy known as the Straw Man Argument.
Knowing a few basic things, such as how to think and put together a rational argument, can make your life soo much easier while keeping all of us out of the dark ages!
I have no problem with your religion until you decide it's reason to deprive others of the truth.
Everyone might want to remember that they cannot "see" any of these alleged planets they keep coming up with. Gee, I wonder why they can't explain their findings!
This was followed up on the astro mailing lists as faulty data -- the observers mistook sunspot-dimming for a planet passing in front of the star. The correction hasn't made it to journalists yet and the science article is still in draft, so no link-to-reference, sorry! Planetary formation theory is fragmented and deeply in need of reworking (anyone want a phd topic?), but not to incorporate Jupiters in Mercury-orbits (yet).
The density of Jupiter is about 4/3, so 21 times that would put it at 28 and change. That means it would have to be significantly denser than Iridium (about 22). That means it would have to be either:
Guess where I'd put my money...
--MarkusQ
that the faster an object is moving the more massive it is. Now if it's the size of jupiter and it is orbiting its sun in only 4 hours then even if it were really close to the sun it would still be moving really really quickly. I know they probably take the speed into consideration when determining its mass. But it's fun to think about.
Because the astrological community is too busy hoodwinking people with talk of Jupiter in the Second House, and horoscopes, and other nonsense.
In some systems, yeah, it is. Set c=1 (space-time unification), measure masses and energies in the same units (E=mc^2), and so on. But I (obviously) wasn't using one of those systems, I was using g/cm^3, as you probably realized.
--MarkusQ
Comprised of PS3? It will be hotter than the sun if someone turns that thing on and starts folding!
Diameter in gas giants does not correlate well to mass. If Jupiter were significantly more massive than it is it would actually be smaller as it's density would increase.
Not to be a party pooper, but a Dyson sphere would surround the star, not orbit it.
http://en.wikipedia.org/wiki/Dyson_sphere
Could this not be a binary star system that the primary pulled enough mass off the secondary to take it below the mass required to fuse? It seems unlikely, but the universe is a rather large place, and we have seen so very little of it. Or possibly an ancient stellar core remnant that was captured? Maybe we are just seeing the last 100k years of the process. With an orbital period of less than 5 days, that planet is humming along, maybe it is a decaying orbit that will result in a collision and an even more spectacular event to be witnessed by some future generation. Heck, just for sheer scifi speculation, maybe its a neutron star that burned itself out 5 billion years ago and accreted enough new material to appear planet sized, those are certainly dense enough, something on the order of a teaspoon worth of neutron star is near the weight of the Earth.
Or more likely, its a observational error that will be corrected with further study.
Only tyrants and oppressors need fear a well armed populace.
Sun in the middle, Sun in the middle
Dyson Sphere's got the Sun in the middle, and a great big bubble all around.
Do not mock my vision of impractical footwear
There are two ways of detecting exoplanets:
1. Wobbles -- what you explained: watch a star for deviations in its orbit by observing tiny redshifts and blueshifts. Our own sun does a little jiggle thanks mostly to Jupiter.
2. Dimness -- what they did for this object. Watch a star for dimming as something passes in front of it, although you have to be careful of other causes of temporary decreases in luminescence (like sunspots).
In both cases, it really needs repeated observations over time to establish that it's an orbital event and not something random. In the good ol' days of exoplanet discovery when the equipment wasn't so hot & we expected to find planets pretty much like ours, it took a whole lot of observations before anyone was willing to take the risk of announcing a discovery. Now, with better equipment making it easier to detect hiccups in a star's routine and a more open attitude about how planets behave, discoveries are being announced a lot earlier in the observation process.
To be fair, TFA does give itself a whole lot of wiggle room in interpreting the data. It just fails to mention that follow-up observations aren't confirming the orbital parameters of the assumed planet.
How dense is the Death Star?
I bet more than 4/3....
Good point. This planet should be about
(0K+6000K)/2
------------------
150000000K
or about 1/50000 the temperature and thus could on that basis be up to 50000 times as dense.
But that can't be the whole picture. At those pressures you'd no longer be dealing with a gas--the volume-per-atom of He would be way out of line. A helium atom occupies about (3.1e-9 cm)^3 or 3e-26 cm^3, and has a mass around 4 * 1.66e-27 kg = 6.66e-24 g, for a per-atom density of about 222 g/cm^3.
So if you could get a core making up maybe 10% of the volume as crystalline helium, I suppose you could do it.
--MarkusQ
Comment removed based on user account deletion
Yeah, well all you people born with Sedna in Puppis think astrology is bunk. Bet you've got Quaor in your House of Pancakes too.
Who is John Cabal?
How do you know? Maybe Athiesm is a new religion they made up, where his god is contained in a Coca Cola bottle with a misspelled label....
"City hall" in German is "Rathaus" Kinda explains a few things......
Actually, I don't think that metallic hydrogen is twice as dense as solid lead.
If you look at most metals, the higher the atomic weight, the higher the density of the solid. Depleted uranium is heavy, while Aluminium is lightweight, and Lithium is half the density of water, for example. So for hydrogen, metallic or not, to be denser than lead, you need it to be packed tighter than, I think, is physically possible.
At some quick maths, a hydrogen atom is 1, lead is 207-208 (82 protons and a load of neutrons.) I know that some mass is actually in the binding energy between those, but for some quick and very approximative maths let's say a lead atom is 200 times heavier than a hydrogen one. (Plus/minus something.) At the same distance between atoms, lead will be 200 times heavier than hydrogen. To go for twice as heavy, you need the hydrogen atoms to be packed at over 7 times less distance from each other than lead atoms are.
At a quick googling, the estimated range of densities for metallic hydrogen is anywhere between 0.4g per cubic centimetre (less than lithium) and 4g per cc (4 times as heavy as water), with apparently 0.8 being the most likely candidate for where it turns metal. Compress it any denser and it'll start to fuse. And we're still nowhere near as heavy as we need for that planet.
What throws a further spanner into it, is that our own gas giants _already_ have a core of metallic hydrogen. That' what's in the middle of Jupiter and Saturn. So something 26 times heavier, hmm, must be something else.
A polar bear is a cartesian bear after a coordinate transform.
Yes and no. Mostly no. At 3000K you might have a plasma, but I'd be surprised to see a super fluid. And I don't expect to see neutronium, tight concentrations of dark matter, or anything like that. So apart from possible, we should be looking at the usual solid / liquid / gas situation.
In any case, the normal laws of physics should still apply.
Back to the subject line, I realized after posting the grandparent that the van der Waals radius would give the more appropriate density figure (in that as you get smaller than that you start hitting hard QM limits). That pulls the density down by two orders of magnitude or so (140/31)^3, putting the limit around 2 g/cm^3--which incidentally gives a fairly good agreement with the measured density and bulk modulus of crystalline helium under laboratory.
So I'm not buying compressed H/He/etc. as obtaining that sort of density in that sort of package at those temperatures.
--MarkusQ
Brown dwarfs don't get to that density by gas compression. The reason the size flattens out is that they reach a point where internal pressure suffices to form a degenerate matter core (note that degenerate matter was on my list).
--MarkusQ
Except that if they used Newtons nobody who was not a scientist or engineer would understand what the article was talking about...
A place where you have LittleBigAdventures, and throw a rubber ball around a lot.
Just a thought, and a bit off-topic, I know, but I was wondering if there is an Absolute Maximum Temperature? Like the opposite of absolute zero (Zero Kelvins). I'm no Physicist (you'd never have guessed, would you?) but as I understand it at Zero K the sub-atomic particles stop moving so energy effectively ceases to exist, so is there a max temp where these are so energetic that matter ceases to exist and becomes pure energy. Or am I just talking a load of sh1t?
Smivs on the intertubes!
And how could a Dyson sphere which is hollow by definition could be anywhere near that massive/dense?
You just got troll'd!
Yeah, someone had to say it. And they beat you to it (see the first post).
You just got troll'd!
Why do you think he has the title of Bad Astronomer? Only a Good Astronomer would have admitted to weighting 4,200 kilogram-force on that planet.
You just got troll'd!
It is a combination of a dyson sphere and the death star.
That is the sort of unlabeled density I was throwing around in the first place, but IIRC there are some systems in which it truly dimensionless. To get there you start measuring things that are equivalent in the same units. Say you decide to start with meters. You can measure time in meters using the space time formulation (so you are measuring the interval between events via I = sqrt(delta:x^2 + delta:y^2 + delta:z^2 - delta:t^2) instead of measuring just time or just distance). When you do this some things (such as scalar velocity) become unitless ratios. In the case of velocity, they become a number between 0 (rest) and 1 (c). All normal speeds are very small numbers in this system.
Likewise you can measure mass and energy in the same units (e.g. electron volts), rendering things like the power of an explosive or the heat of crystallization of some material as unitless (and very small) number.
When you drag in thermodynamics (IIRC you also have to pull information theory and QM to make this work) you can start measuring even lore things things in the same terms (e.g. information in m^2, where one bit = 1/4 of a square planck length or something like that). Eventually, you get to measuring mass in the same terms as volume, making density unitless.
IIRC, in such a system the density of lead is something like 10^240, making it all but useless for the sort of back-of-the-email-envelope calculation I was doing, but still, it's there.
--MarkusQ
P.S. Although this may seem like a strange way to look at units, remember that we already do some unification--we measure differences in altitude in the same units that we use for north-south and east-west distances, we measure the weight of wheat in the same units we use for rice, and so on. It's just a question of where you stop.
No, you were right in your interpretation, I was mostly betting on data error, though brown dwarf would be a good second bet. I'm going off a physics education that's got twenty plus years of dust on it and half these posts have been made with a kid or a cat on my lap, so I won't claim rigorous analysis here, but I'm not convinced. There are various reasons (tidal interactions, catchment competition, etc.) that I'm unconvinced that it could have formed in situ. And there are statistical reasons for doubting that it migrated there. So I'm skeptical.
I will admit that I've become less so after earlier reports that had the star much denser (based on a mass of 3.7 M(s) vs. the measured 1.37 M(s)) have been corrected.
--MarkusQ
Entitled _Satan's Planet_?
As an agnostic who borders on athieism, I find it scarier that you think this is a relevant response to the subject. It seems "Faith" is affecting your mind adversely. Seems to be a very common side effect as far as I can tell... Go home and sacrifice a goat or drink some wine or whatever it is you deluded people do when you aren't trolling on Slashdot.
"People are stupid; given proper motivation, almost anyone will believe almost anything."
In at least one sense, there obviously is a highest possible temperature, and in another, there can't possibly be. If there is a highest temperature, it is probably the planck temperature, unless it's the hagedorn temperature, or, under a certain crafty merger of cosmology and negative temperatures the maximum might be -0k.
Unless it's something else. Or unless there isn't one.
--MarkusQ