Beta

Slashdot: News for Nerds

×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Massive Exoplanet Discovered, Challenges Established Planet Formation Theories

samzenpus posted about 7 months ago | from the biggest-yet dept.

Space 129

sfcrazy writes "A giant exoplanet that is in the most distant orbit ever seen around its host star, has been recently discovered. Dubbed HD 106906 b, the newly discovered planet is relatively young (13 million years old, compare this to our 4.5 billion years old Earth) and bigger than any other planet discovered till date. It is 11 times the size of Jupiter, and that's what makes it a most singular discovery."

cancel ×

129 comments

Can someone who knows about astronomy fill me in? (4, Interesting)

bigHairyDog (686475) | about 7 months ago | (#45639169)

How do astronomers calculate the age of a distant planet? I can see how they'd get distance from host star (orbital period) and mass (displacement of host star) but how on earth do you work out the age?

Re:Can someone who knows about astronomy fill me i (5, Funny)

somersault (912633) | about 7 months ago | (#45639215)

By counting the rings, obviously ;)

Re:Can someone who knows about astronomy fill me i (0)

aardvarkjoe (156801) | about 7 months ago | (#45639929)

That only works if you can cut it in half first.

Re:Can someone who knows about astronomy fill me i (0)

InsightfulPlusTwo (3416699) | about 7 months ago | (#45641325)

That doesn't work for every planet. Clearly, your head is stuck in Uranus.

Re:Can someone who knows about astronomy fill me i (1)

xevioso (598654) | about 7 months ago | (#45641573)

You know, if Johann Elert Bode, the man who ultimately named Uranus, had any inkling that the naming of the planet in this way would lead to the untold gazillions of sexual puns made with his choice, he would have killed himself.

Re:Can someone who knows about astronomy fill me i (1)

mrsquid0 (1335303) | about 7 months ago | (#45641791)

When Uranus was discovered the common pronunciation for the old Greek sky god's name was something akin to urine-us, which at the time was considered far more vulgar than the ur-anus pronunciation. Today it is the other way around. Who knows which pronunciation will be considered ruder (or more childish) a few centuries from now.

Re:Can someone who knows about astronomy fill me i (2)

Teun (17872) | about 7 months ago | (#45641979)

He was German, why do you guy's think the English language part of the world should pronounce Uranus different to the way the discoverer intended?

Re:Can someone who knows about astronomy fill me i (0)

Anonymous Coward | about 7 months ago | (#45642085)

You know, if Johann Elert Bode, the man who ultimately named Uranus, had any inkling that the naming of the planet in this way would lead to the untold gazillions of sexual puns made with his choice, he would have killed himself.

Ummm, why would you confuse scatological jokes about rectal sphincters with sexual puns?

Re:Can someone who knows about astronomy fill me i (0)

Anonymous Coward | about 7 months ago | (#45639239)

I would guess it's an estimate based on the age of the star, which we can figure out. Perhaps the age of the star combined with what we know about the speed of planet formation?

Re:Can someone who knows about astronomy fill me i (2)

Opportunist (166417) | about 7 months ago | (#45639581)

And what exactly do we know about planet formation? If anything, we have a hunch how our system formed, but it's neither certain nor do we have any clue whether it's the norm. We already know that our system is in some ways "special", from the rather high amount of trans-HE material to its position in the galactic disc to the mere fact that it's not a multi-star system.

Re:Can someone who knows about astronomy fill me i (1)

davidmcg (796487) | about 7 months ago | (#45639845)

I remember reading something some time ago about how light from a distant object is used to determine the composition of a star, or a planet. As different elements produce a difference wavelength of light, this can be used to determine the composition of a stellar object and by comparing this to other known objects with similar composition, this can be used to determine how the object was formed and it's relative age.

Re:Can someone who knows about astronomy fill me i (3, Informative)

Shadowmist (57488) | about 7 months ago | (#45641137)

And what exactly do we know about planet formation? If anything, we have a hunch how our system formed, but it's neither certain nor do we have any clue whether it's the norm. We already know that our system is in some ways "special", from the rather high amount of trans-HE material to its position in the galactic disc to the mere fact that it's not a multi-star system.

Actually we still don't know enough about stellar formation to determine how far from the norm, the Solar System actually is. The reason that we find so many oddball systems and planets is that those are the easiest systems and planets to find. We are in a form golden area of our Galaxy, far enough from the galactic center that we're not subject to it's nasty radiation and stellar activity, yet not so far that we'd lack in heavy elements. Keep in mind also that most planet detection methods rely on the target solar system being oriented edge on towards us so the planet can intercept the star's light by passing between it and us. That's going to leave a lot out.

Re:Can someone who knows about astronomy fill me i (3, Insightful)

amiga3D (567632) | about 7 months ago | (#45639247)

Guesswork. They take what they think they know and use it to make a guess that will change every time they find out what they thought they knew was wrong. It's fun to follow but don't put too much faith in it.

Re:Can someone who knows about astronomy fill me i (-1, Offtopic)

aliquis (678370) | about 7 months ago | (#45639469)

Guesswork. They take what they think they know and use it to make a guess that will change every time they find out what they thought they knew was wrong. It's fun to follow but don't put too much faith in it.

It sure beats: "Because God!"

Re:Can someone who knows about astronomy fill me i (2, Insightful)

Anonymous Coward | about 7 months ago | (#45640117)

Too bad your comment doesn't.
 
Seriously, the religion-bashing knee-jerk comments are garbage. Too bad the mods don't have the common sense to just mod you as off topic or over rated and maybe you'd be forced to make an actual intelligent contribution to the conversation to maintain a good karma.
 
If you're only contribution to science is shouting down theists than you're not doing much better than the theists shouting down science. Go pick up a book and learn a little science and have something more than a lame warn-out old crutch to hold you up in these kinds of conversations.

Re:Can someone who knows about astronomy fill me i (1)

nucrash (549705) | about 7 months ago | (#45640997)

No offense, but he kept his remark short and sweet. He didn't go into some serious diatribe about how religion is tearing down society or more. Because of that, I give him a pass. I would have probably worked the system a bit more explaining the evils and blah blah blah, I am bored and think I will go get a cookie.

Re:Can someone who knows about astronomy fill me i (2, Insightful)

Anonymous Coward | about 7 months ago | (#45639503)

If you don't have any information to provide, please don't try to act like you do.

"They take what they think they know and use it to make a guess"

Thanks for that brilliant insight.

Re:Can someone who knows about astronomy fill me i (1)

amiga3D (567632) | about 7 months ago | (#45640579)

Am I wrong? It's exactly what happens. A guess based on the slimmest of knowledge. I can't count how many times I've seen these sudden bursts of enlightenment get changed when everything they thought they knew gets turned upside down. It's a guess and only by the loosest term an educated one. I'm sorry if the facts hurt your feelings.

Re:Can someone who knows about astronomy fill me i (3, Funny)

jabberwock (10206) | about 7 months ago | (#45639251)

They got a birthday notification from the planet's Facebook page.

Attention! Mod parent DOWN! (0)

Anonymous Coward | about 7 months ago | (#45639437)

I work at Facebook. You do NOT see the date of which a person was born with said birthday notifications. I suggest you go home and do your homework.
 
-Indra Kumar

Re:Attention! Mod parent DOWN! (1)

jabberwock (10206) | about 7 months ago | (#45639623)

Wow. Touchy. It was funny anyway, Indra, if you don't work at Facebook. Because the freakin' birthday notifications are a plague on the planet.

Re:Attention! Mod parent DOWN! (5, Funny)

sharknado (3217097) | about 7 months ago | (#45639969)

I work at Facebook. You do NOT see the date of which a person was born with said birthday notifications. I suggest you go home and do your homework.

What's more distressing is that you, a Facebook employee, know that he's not at home. Dun dun dunnnn....

Re:Can someone who knows about astronomy fill me i (5, Informative)

Virtucon (127420) | about 7 months ago | (#45639269)

Re:Can someone who knows about astronomy fill me i (4, Interesting)

bigHairyDog (686475) | about 7 months ago | (#45639803)

Nice article, but that only says how they get the age of a star. I suppose that puts an upper limit on the age of the planet.

Re:Can someone who knows about astronomy fill me i (0)

Anonymous Coward | about 7 months ago | (#45640511)

Nice article, but that only says how they get the age of a star. I suppose that puts an upper limit on the age of the planet.

At least if we assume that the planet was formed with the star. But what if the planet had formed around another star, and then was ejected from that system due to some disturbance, to be later captured by the star it is circling now?

Re:Can someone who knows about astronomy fill me i (1)

Shadowmist (57488) | about 7 months ago | (#45641169)

Nice article, but that only says how they get the age of a star. I suppose that puts an upper limit on the age of the planet.

At least if we assume that the planet was formed with the star. But what if the planet had formed around another star, and then was ejected from that system due to some disturbance, to be later captured by the star it is circling now?

That would be kind of tricky. The planet is moving at escape velocity from it's original star, in most cases, encountering another solar system would have it either just passing through, or it would wind up in a very eccentric orbit. which would not necessarily be in the same plane as the local ecliptic.

Re:Can someone who knows about astronomy fill me i (0)

Anonymous Coward | about 7 months ago | (#45642055)

A planet coming from outside the system would pass right through, having too much momentum to stick around because any speed it gains from falling into the system's gravity well is exactly how much it will need to leave. So it needs some way to shed momentum, requiring a significant amount of other mass to fling away from the system, i.e. another planet. So while there might be some differences between the planet ejected and the one that came in, you would still have to deal with a planet or one of several planets forming at that distance. Not to mention the chances of it lining up like that are pretty small.

Re:Can someone who knows about astronomy fill me i (1)

osu-neko (2604) | about 7 months ago | (#45641083)

Nice article, but that only says how they get the age of a star. I suppose that puts an upper limit on the age of the planet.

More than an upper limit. Unless the planet is a captured rogue, knowing the age of the star gives you the age of the planet, pretty much. If you know the age of someone's heart, you know the age of their head, too (transplant patients excepted).

Re:Can someone who knows about astronomy fill me i (2)

DiEx-15 (959602) | about 7 months ago | (#45639361)

How do astronomers calculate the age of a distant planet? I can see how they'd get distance from host star (orbital period) and mass (displacement of host star) but how on earth do you work out the age?

They can't accurately predict it to a degree of 100% certainty. However they can guess based on it's radiation level and it's decay of said rad signal. They can also compare it to surrounding star systems and see if they have been influenced for an extended period of time or more recent (recent as in millions of years ago instead of billions of years).

It's not an exact science but at least it gives them a ballpark figure until they can manage to actually get to that planet and get samples. However, that may not happen in anybody's lifetime.

Re:Can someone who knows about astronomy fill me i (2)

JeffAtl (1737988) | about 7 months ago | (#45639701)

The problem in this case is that the discovery supposedly has the potential to challenge existing planet formation theories. If that is true, then the methodology to calculate this planet's age may be flawed.

Re:Can someone who knows about astronomy fill me i (0)

Anonymous Coward | about 7 months ago | (#45640591)

However they can guess based on it's radiation level and it's decay of said rad signal.

That is partially related to how they can look at ages of planets they get samples from or can send probes to, by looking at isotope ratios. But you're not going to get any sort of radiation decay from a planet light years away, only stuff from active processes or in the rare chance you catch something within a million years of still cooling off and looking at IR.

Re:Can someone who knows about astronomy fill me i (4, Informative)

bigHairyDog (686475) | about 7 months ago | (#45639869)

OK I answered my own question with some googling.

The age of the exoplanet is not independently derived, but instead, taken from the age of the host star. This too can be difficult to determine. For isolated stars, there are precious few methods (such as gyrochronology) and they generally have large errors associated with them. Thus, instead of looking for isolated stars, astronomers searching for young exoplanets have tended to focus on clusters which can be dated more easily using the main sequence turn off method.

http://www.universetoday.com/76495/the-hunt-for-young-exoplanets/ [universetoday.com]

Re: Can someone who knows about astronomy fill me (0)

Anonymous Coward | about 7 months ago | (#45640003)

Science bitch!

Re:Can someone who knows about astronomy fill me i (2)

CBM (51233) | about 7 months ago | (#45640733)

A paper by Bailey et al. is here... http://arxiv.org/abs/1312.1265

The age is estimated from the primary star. Presumably the system formed all at the same time, star and planet together. (It's difficult to gain a planet in some other way, such as "capture," especially in such a short period of time since the star's birth.)

The planet's mass is estimated from the brightness and color of the planet. HD 106906 b is a rare case where the companion can be resolved from its primary so a spectrum can be measured. Known models of planet brightness can be used to work backwards from the brightness and color to get mass.

Distance is usually a hard one to solve, but in this case the star is bright and Hipparcos has a distance derived from parallax. A distance of 92 parsecs means that the annual parallax is 1/92 arcsec. For comparison the moon is 1800 parsecs in diameter.

Re:Can someone who knows about astronomy fill me i (2)

AthanasiusKircher (1333179) | about 7 months ago | (#45640763)

but how on earth do you work out the age?

Umm, the same way you work it out on other planets??

[ducks]

upswing in unstraightenings noted (-1, Offtopic)

Anonymous Coward | about 7 months ago | (#45639171)

religious abuse victims world wide easing into identity challenges,,, 'we like everybody the same' is the typical entry point now

the #1 answer ought to be; who cares?

Upper limit on planets? Lower limit on stars (1)

KingOfBLASH (620432) | about 7 months ago | (#45639255)

Becoming a star requires at a minimum many times the mass of jupiter. As small stars exist, there's therefore a likelihood that there are gas giants almost as big a the minimum to make a star.

A quick google seems to suggest that's 8% the size of the son

As Jupiter is 0.1% size the son, 11x the size of jupiter doesn't seem that big. We should be able to find "planets" up to almost 80x larger

http://www.space.com/21420-smallest-star-size-red-dwarf.html [space.com]
http://www.wolframalpha.com/input/?i=jupiter%20mass%20compared%20to%20sun&t=crmtb01 [wolframalpha.com]

Re:Upper limit on planets? Lower limit on stars (4, Funny)

Anonymous Coward | about 7 months ago | (#45639337)

that's 8% the size of the son

Or 0.003% the size of yo momma.

Re:Upper limit on planets? Lower limit on stars (3, Funny)

GodfatherofSoul (174979) | about 7 months ago | (#45640021)

Yo mama so fat, if she was any bigger she'd start fusing hydrogen.

Re:Upper limit on planets? Lower limit on stars (1)

arisvega (1414195) | about 7 months ago | (#45640091)

Yo mama so fat, if she was any bigger she'd start fusing hydrogen.

Yo momma SO fat, every time I am done visiting her, I have to break orbit.

Re:Upper limit on planets? Lower limit on stars (0)

Anonymous Coward | about 7 months ago | (#45639365)

Around 13 Jupiter masses they become known as brown dwarves. So it's not that we don't know of objects that are of this mass. I think where some of the question comes in is if brown dwarves should be considered stars or not.... I'm not sure how the IAU terms this.

Re:Upper limit on planets? Lower limit on stars (1)

emj (15659) | about 7 months ago | (#45639373)

Wikipedia says that at 13 times the size of juptiter you get something that can ignite and you get a brown dwarf.. How that is calculated is beyond me..

Re:Upper limit on planets? Lower limit on stars (1)

sharknado (3217097) | about 7 months ago | (#45639983)

My brown dwarfs are typically much smaller than that.

Re:Upper limit on planets? Lower limit on stars (1)

rubycodez (864176) | about 7 months ago | (#45640009)

the Tall Man can do custom orders?

Re:Upper limit on planets? Lower limit on stars (5, Informative)

Zephyn (415698) | about 7 months ago | (#45640075)

That's the mass threshold for deuterium fusion. No fusion = planet, deuterium fusion = brown dwarf, hydrogen fusion = main sequence star.

So at 11 Jovian masses, the planet is close, but not quite big enough to reach brown dwarf status.

Re:Upper limit on planets? Lower limit on stars (0)

Anonymous Coward | about 7 months ago | (#45640727)

| No fusion = planet, deuterium fusion = brown dwarf, hydrogen fusion = main sequence star.

I thought that our star, (the sun), used deuterium fusion as it's primary mechanism for producing energy, and that it's not hot enough to produce direct hydrogen fusion????
(With the mutual annihilation of positrons and electrons produced by the deuterium fusion producing a bit less than 10% of the sun's energy output.)

Re:Upper limit on planets? Lower limit on stars (0)

Anonymous Coward | about 7 months ago | (#45640857)

At the sun's mass Deuterium isn't needed but could be there. Even the largest brown dwarf has a problem with anything beyond lithium.

Re:Upper limit on planets? Lower limit on stars (0)

Anonymous Coward | about 7 months ago | (#45642121)

D-D fusion doesn't get you any positrons (nor neutrinos, which have been observed). D-D fusion is also much easier than p-p fusion. The sun is quite capable of performing p-p fusion, which produces deuterium and positrons, and then the deuterium gets used up too. The details of the process, and what happens after deuterium because it is temperature dependent, is covered on Wikipedia [wikipedia.org]

Re:Upper limit on planets? Lower limit on stars (1)

SlippyToad (240532) | about 7 months ago | (#45640097)

How that is calculated is beyond me

A certain amount of mass equals a certain amount of pressure, which is what's required to start hydrogen fusing.

Re:Upper limit on planets? Lower limit on stars (1)

arisvega (1414195) | about 7 months ago | (#45640187)

Wikipedia says that at 13 times the size of juptiter you get something that can ignite and you get a brown dwarf.. How that is calculated is beyond me..

From hydrostatics: the more mass you build up, the higher the pressure --and the temperature-- becomes in the core, and then you reach a point where the temperature is high enough to start fusing stuff up (as per definition of 'a star'). This, for hydrogen, happens at some mass limit or other which is at around a few Jupiter masses.

It is a back-of-the-envelope calculation really, though there are a few other, more sophisticated models, around.

Re:Upper limit on planets? Lower limit on stars (4, Interesting)

MBGMorden (803437) | about 7 months ago | (#45639419)

Well, mass and size get thrown around a lot semi-interchangeably which they're most definitely not.

80x the MASS of Jupiter and something becomes a star, but the established theory IIRC was that until you get to that point you keep cramming things in and the planet itself just kinda compresses more and doesn't get much bigger than Jupiter. If it ever gets big enough to become a star and achieve fusion then the pressure pushes it out and then it gets better.

So if it is as the summary says and the planet is literally 11 times the size of Jupiter then that's quite a find. It basically says that there's either something wrong with either a) our understanding of planet formation or b) there's something wrong with how we measured this and the data is just wrong.

If its 11 times the mass then yeah - kind of boring and expected.

Re:Upper limit on planets? Lower limit on stars (3, Funny)

SJHillman (1966756) | about 7 months ago | (#45639973)

"If it ever gets big enough to become a star and achieve fusion then the pressure pushes it out and then it gets better."

Unless you live there. Then it gets worse. Much worse.

Re:Upper limit on planets? Lower limit on stars (1)

MBGMorden (803437) | about 7 months ago | (#45640509)

Ah. Typing goof. Meant to say bigger, not better. Often times those are as misused as the mass and size situation though :).

Re:Upper limit on planets? Lower limit on stars (1)

MiniMike (234881) | about 7 months ago | (#45640043)

So if it is as the summary says and the planet is literally 11 times the size of Jupiter then that's quite a find. It basically says that there's either something wrong with either a) our understanding of planet formation or b) there's something wrong with how we measured this and the data is just wrong.

Maybe it's just 11x closer than they think it is, and moving away faster than expected. Would still be an interesting system to find.

Re:Upper limit on planets? Lower limit on stars (2)

edjs (1043612) | about 7 months ago | (#45640521)

Bad summary. The point of the article is that:

- the distance the planet is orbiting its primary is much farther out than current planet formation theories support.
- the planet is not massive enough compared to the primary to fit the theories on binary star formation.

Re:Upper limit on planets? Lower limit on stars (1)

Shadowmist (57488) | about 7 months ago | (#45641205)

Becoming a star requires at a minimum many times the mass of jupiter. As small stars exist, there's therefore a likelihood that there are gas giants almost as big a the minimum to make a star.

A quick google seems to suggest that's 8% the size of the son

As Jupiter is 0.1% size the son, 11x the size of jupiter doesn't seem that big. We should be able to find "planets" up to almost 80x larger

http://www.space.com/21420-smallest-star-size-red-dwarf.html [space.com] http://www.wolframalpha.com/input/?i=jupiter%20mass%20compared%20to%20sun&t=crmtb01 [wolframalpha.com]

Those are objects known as Brown Dwarfs which would put them at a different category than Jovian planet. I believe that the minimum mass to establish fusion is something on the order of one tenth solar mass. Brown Dwarves radiate Infared radiation due to heat from residual gravitational collapse. Presumably the standard is considerably higher than Jupiter which also radiates more heat than it absorbs from the Sun.

Re:Upper limit on planets? Lower limit on stars (0)

Anonymous Coward | about 7 months ago | (#45641559)

Holy fuck, you don't know how to spell 'sun'?

Re:Upper limit on planets? Lower limit on stars (1)

budgenator (254554) | about 7 months ago | (#45641765)

Brown dwarfs are substellar objects too low in mass to sustain hydrogen-1 fusion reactions in their cores, unlike main-sequence stars, which can. They occupy the mass range between the heaviest gas giants and the lightest stars, with an upper limit around 75[1] to 80 Jupiter masses (MJ). Brown dwarfs heavier than about 13 MJ are thought to fuse deuterium and those above ~65 MJ, fuse lithium as well.[2] Brown dwarf [wikipedia.org]

There is a class of objects between planets and red dwarf binaries.

11 times the size of Jupiter? (1)

Virtucon (127420) | about 7 months ago | (#45639257)

The Gravity must be immense, we'll need to ban their Olympic athletes from participating in the summer games.

Re:11 times the size of Jupiter? (0)

Anonymous Coward | about 7 months ago | (#45639275)

We'll advise your mother straight away.

Re:11 times the size of Jupiter? (4, Informative)

SJHillman (1966756) | about 7 months ago | (#45639655)

If it's 11 times the diameter, then gravity would be pretty tame at the surface unless it's extremely dense. For example, Jupiter's diameter is 11.2 times that of Earth, but the surface gravity is only 2.64 times that of Earth. Saturn and Uranus both have equatorial surface gravities roughly equal to Venus, in spite of being 9.44 and 4 Earth diameters, respectively.

Source: http://www.windows2universe.org/our_solar_system/planets_table.html [windows2universe.org]

Re:11 times the size of Jupiter? (0)

Anonymous Coward | about 7 months ago | (#45640669)

Most gas exoplanets don't get much bigger than Jupiter, with roughly a factor of 2 bigger if very close to the star and much hotter. At a point, density goes up a lot instead of the physical extent. So it probably has a "surface" gravity of at least 2.5 times that of Jupiter, and possibly not far off from 11 times as much.

Re:11 times the size of Jupiter? (1)

wonkey_monkey (2592601) | about 7 months ago | (#45641019)

If it's 11 times the diameter

It's not - it's 11 times the mass.

And it's name is... (0)

Anonymous Coward | about 7 months ago | (#45639267)

Gallifrey!

But seriously. The coincidence of this timing is just... amazingly awesome.

Guys, accept calling it Gallifrey now. I'm sure everyone knows the Whovians are going to start some massive petition to do it anyway.

Re:And it's name is... (1)

wonkey_monkey (2592601) | about 7 months ago | (#45639497)

But seriously. The coincidence of this timing is just... amazingly awesome.

What, discovering a planet - presumably a gas giant, not a rocky world like Gallifrey - 11 times the size of Jupiter a couple of weeks after a TV show featured a planet a few times bigger than Earth?

Yeah, wow. It's like they knew, or something.

They're discovering planets at a rate of about one every two days now (probably more, that was just based on a list I found for 2013) and most of those would be much closer in size to Gallifrey. All, in fact, since this one is the biggest we know of.

Re:And it's name is... (1)

Virtucon (127420) | about 7 months ago | (#45639511)

I can hear the Whovians now.. but wait in "End of Time" when Gallifrey appears next to earth it's only like 5 times the size of the earth.. Jupiter is 1321 times the size of the earth [universetoday.com] and this planet is 11 times that. Besides all the Timelords would be walking around and looking all squatty like Sontarans.

Re:And it's name is... (2)

JustOK (667959) | about 7 months ago | (#45639753)

It's bigger on the surface, duh!

Re:And it's name is... (2)

SJHillman (1966756) | about 7 months ago | (#45639799)

Jupiter's volume is 1,321 times Earth, but its diameter is only a little over 11 times Earth's. I believe diameter is what you're thinking when you say Gallifrey appears five times the size of Earth. If its volume was five times the size of Earth, the diameter (assuming perfect spheres for the sake of simplicity) would be about 1.71 times the size of the Earth. It's hard to find a good picture of Gallifrey next to Earth from that episode in which the two are equidistant from the observer, but based on the one linked below, I'd say Gallifrey is, at a minimum, 2.5 Earth diameters, giving it a volume of at least 65 Earths and a surface area. Of course, it's a fictional planet, so the real answer is that it's however big they tell us it is and everything else is a trick of the light.

http://www.flickfilosopher.com/wptest/wp-content/uploads/2010/01/dwbigassgallifrey1.gif [flickfilosopher.com]

Re:And it's name is... (1)

SJHillman (1966756) | about 7 months ago | (#45639811)

Looking back, I think I mixed up radius and diameter in a few calculations, so... bonus points and cookies to anyone that corrects them.

Re:And it's name is... (1)

Shadowmist (57488) | about 7 months ago | (#45641255)

Mention Star Trek or Doctor Who in a science thread and you effectively Goodwined it.

Re:And it's name is... (0)

Anonymous Coward | about 7 months ago | (#45640737)

But seriously. The coincidence of this timing is just... amazingly awesome.

Considering for the last couple years over 100 exoplanets a year are discovered, with a bias toward larger planets, real exoplanets are probably being discovered faster than new planets are named in all currently broadcast sci-fi TV shows together.

So if we send out the black monolith now (1)

Sam_In_The_Hills (458570) | about 7 months ago | (#45639273)

it should get there at just about the right time to teach the pre-dawn humans about the wonders of violence. How about instead we fill this one with Youtube cat videos and see how the planet evolves?

Re:So if we send out the black monolith now (2)

JustOK (667959) | about 7 months ago | (#45639771)

It's been done. Except when it came their turn to do it, they sent back telephone sanitization kits.

Explanation (0)

Anonymous Coward | about 7 months ago | (#45639293)

It was originally a small planet and it was even demoted to a dwarf planet. When the protests to reinstate it didn't work, the protesters said "oh yeah? watch us". They poured material on it. A lot of it.

That's no Exoplanet! (1)

Idou (572394) | about 7 months ago | (#45639487)

Just kidding . . . but, seriously, I am really not looking forward to when they actually do discover a death star . . .

Re:That's no Exoplanet! (0)

Anonymous Coward | about 7 months ago | (#45639541)

Why? Discovery of an actual artificial object out there would be just about the coolest news ever.
It's not like it could ever get here.

Re:That's no Exoplanet! (1)

Sabriel (134364) | about 7 months ago | (#45640257)

So your guess on humanity's reaction to discovering a stellar engine, ringworld or similar megastructure would be...?

Is is most singular is right (1)

Anonymous Coward | about 7 months ago | (#45639507)

whatever that means.

Singular discovery (1)

wonkey_monkey (2592601) | about 7 months ago | (#45639565)

It is 11 times the mass [FTFY] of Jupiter, and that's what makes it a most singular discovery.

Much as I enjoy the Sherlockian prose, every time we discover a new most massive planet, it's going to be a singular discovery.

The missing context here is: how massive was the previous recorder holder?

Not size - mass (1)

wonkey_monkey (2592601) | about 7 months ago | (#45639583)

It is 11 times the size of Jupiter, and that's what makes it a most singular discovery.

Oh dear. Do we have to have the talk again?

Re:Not size - mass (1)

allcoolnameswheretak (1102727) | about 7 months ago | (#45639695)

Whooops. Yes, sorry. See comment below. :(

Size? (1)

allcoolnameswheretak (1102727) | about 7 months ago | (#45639683)

I wonder, when astronomers say 11 times the size of Jupiter, does that mean 11 times the radius, the mass, or that you could fill the sphere of its volume with 11 jupiters? Or the circle area as seen from earth?

Re:Size? (1)

SJHillman (1966756) | about 7 months ago | (#45639857)

In order to answer this, I plugged "size" into a dictionary and used the result easiest to work with.

"2. each of the classes, typically numbered, into which garments or other articles are divided according to how large they are.
"I can never find anything in my size""

In other words, if Jupiter wears size 10 pants, this new planet wears size 110. Fatass spacerock needs to lay off the Mars bars.

Re: Size? (0)

Anonymous Coward | about 7 months ago | (#45640099)

For large exoplanets, the unit is almost always x Jupiter Masses. I'm too lazy to look this one up but I'm fairly certain they mean 11 times the mass of Jupiter. I'm certainly no expert but I seem to recall the next largest discovered to be about 9 Jupiter masses.

Re:Size? (1)

edjs (1043612) | about 7 months ago | (#45640471)

I expect astronomers would normally specify mass or radius/diameter rather than use size ambiguously. And the article doesn't use the word size, so can't fault the journalist. Summary writers, however ...

(11 x mass BTW)

Re:Size? (0)

Anonymous Coward | about 7 months ago | (#45640473)

If the specifics are unstated, the meaning usually falls back to informal conversation. In this case, my guess is that it's the apparent diameter--an astronomical description referring to the 2 dimensional disk seen by a distant observer. As an example: the Moon and the Sun from the Earth appear to be the same size.

If the moon were 11 times larger, we would have some killer solar eclipses that would occur more frequently. But the killer tides would mean it would have to be further away to make everything work in the present way. But that would make it appear smaller and ... but, I appear to be digressing into a hypothetical psychosis.

Re:Size? (1)

Shadowmist (57488) | about 7 months ago | (#45641271)

I wonder, when astronomers say 11 times the size of Jupiter, does that mean 11 times the radius, the mass, or that you could fill the sphere of its volume with 11 jupiters? Or the circle area as seen from earth?

It would always be by mass, since it's pretty much nearly impossible to actually get a reading on the radius. Also physics pretty much determines what happens when you've got a gas giant of that mass.

Re:Size? (1)

Virtucon (127420) | about 7 months ago | (#45641275)

I hereby name this planet, Planet Enzyte.

Of course planet formation theory will need fixing (1)

bruce_the_loon (856617) | about 7 months ago | (#45640013)

As the set of planets grows, theories will have to change as we have based the original ones on a single sample that may or may not be representative of the full set.

It's like basing an entire theory of construction of buildings on De Aar, South Africa and while it may explain most small towns, the suburbs of most cities, it will fall apart completely when you try and explain Manhatten or wooden houses in the US with it.

Re:Of course planet formation theory will need fix (1)

ninjabus (3024459) | about 7 months ago | (#45640095)

This object is in an ugly middle between being a separate star or just a planet. Are there any models that consider both star and planet formation as the same process? If we built our programs to model one or the other, it's easy to see why we wouldn't have predicted distant but non-fusing binary partners. Note, it seems that 650 AU is quite distant even for a binary companion, alpha centauri A and B wobble between 16-32 or so AU between them, and have a larger orbit than most.

headline isn't quite correct (5, Informative)

The Bad Astronomer (563217) | about 7 months ago | (#45640083)

The headline as submitted isn't really correct. The planet is not the biggest found; there are several whose mass may be larger, like the exoplanets announced just last week (and this planet has 11 times the mass of Jupiter; we don't know its actual size). The real issue with HD 106906 b is that it is so far out from its parent star, much farther out than planets with that ass should form. Either it formed farther in and got tossed out (which is unlikely) or it formed where it was, which current theories say is difficult; usually objects forming that far out have much higher mass. I explain all this in my own blog post about it [slate.com] .

Re:headline isn't quite correct (0)

Anonymous Coward | about 7 months ago | (#45640799)

The real issue with HD 106906 b is that it is so far out from its parent star, much farther out than planets with that ass should form.

After reading the 'yo momma' jokes a few posts above, not sure if you lost an 'm' there or if it's intentional :)

BTW, the quote at the bottom of the page was surprisingly topical: "New systems generate new problems."
Indeed they do, Slashdot. Indeed they do.

Very Young (2)

SuperKendall (25149) | about 7 months ago | (#45640279)

So are you saying it's a Day Zero Exoplanet?

11 times jupiter? (0)

Anonymous Coward | about 7 months ago | (#45640621)

its a failed star, ergo had it become a star it would be the most common system type

BINARY

Re:11 times jupiter? (1)

Anonymous Coward | about 7 months ago | (#45640833)

If it was binary, that would be only 3 times the mass of Jupiter!

...

...

...

No, I'm not going to apologize for that.

Re:11 times jupiter? (1)

Virtucon (127420) | about 7 months ago | (#45641295)

What about Hexadecimal Star Systems? Do they exist?

Re:11 times jupiter? (1)

jfdavis668 (1414919) | about 7 months ago | (#45641375)

You're using old data. Once we started to find planets, we realized that they can be more massive than we originally thought. Planets go up to about 13 Jupiter masses. Larger than that are brown dwarfs, which go up to 70-80 Jupiter masses. I wouldn't call an 11 Jupiter mass planet a failed star.

Can somebody translate this into standard measurem (0)

Anonymous Coward | about 7 months ago | (#45640697)

I'm sick of all these "x times the size of Earth" metrics.

We have a standard measurement system. Let's use it.

For the scientifically minded among us, how many football fields big is this planet?

Re:Can somebody translate this into standard measu (1)

jfdavis668 (1414919) | about 7 months ago | (#45641779)

How many Olympic pool sizes would it take to fill its volume?

How old is the star? (1)

wjcofkc (964165) | about 7 months ago | (#45641825)

I read both articles but did not see how old the star it's orbiting is. Pardon me if I missed it, I just woke up. It sounds to me like a failed star from the same general region drifted into the gravity well of the star in question, and found a cozy place that far out. Even if the star it is orbiting is much older, they could have still formed from the same gas cloud. Just because it has taken up orbit, does not mean formed there. Perhaps it's mass results in some kind of wild slingshot orbit... perhaps, perhaps, perhaps.

Perhaps this is just another example of the more we learn about science and the universe, the less we know and understand. Funny how it works that way.
Load More Comments
Slashdot Account

Need an Account?

Forgot your password?

Don't worry, we never post anything without your permission.

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>
Create a Slashdot Account

Loading...