This Massive Planet Shouldn't Exist (gizmodo.com) 66
fahrbot-bot shares a report from Gizmodo: Scientists have spotted an unusually large exoplanet in orbit around b Centauri, a massive two-star system that is visible to the unaided eye. With a combined weight of roughly 10 Suns, it's now the heaviest star system known to host a planet. The details of this discovery were published today in Nature. The newly discovered planet, called "b Cen (AB)b," is likely a gas giant and is heavier than 10 Jupiters combined, making it one of the most massive planets ever discovered. It orbits the b Centauri binary system, which is located 325 light-years from Earth and has a combined mass of nearly 10 Suns. At 52 billion miles from its host stars, this planet has one of the widest orbits ever detected. By comparison, Pluto orbits the Sun at around 3.3 billion miles, so yeah, that's an unbelievable separation. Until now, planets had not been found in orbit around star systems weighing more than three solar masses. Astronomers didn't think planets could form around systems like this, so it's forcing a major rethink of what's possible in terms of planetary architectures and the conditions under which planets can form.
That a planet exists in this star system is indeed surprising. Young stars have protoplanetary disks around them, from which planets eventually emerge. A hot star system like b Centauri, however, is not supposed to be conducive to planetary formation, owing to tremendous amounts of ultraviolet and X-ray radiation. This high-energy radiation "tends to destroy the disks in a very short time," and it was "thought that this wouldn't give planets enough time to form in the disk before it disappeared," [said Markus Janson, an astronomer at Stockholm University and the first author of the study]. Yet there it is -- a full fledged planet around the b Centauri system. [...] A neat observation is how the ratio between the masses of the star system and its planet closely matches that of our Sun and Jupiter. But that's where the comparison ends, as the scale of b Centauri is far vaster, as the planet is 10 times the mass of Jupiter and with an orbit that's 100 times wider. [...]
From an astrobiological perspective, Janson added that b Centauri is "possibly one of the worst places in the galaxy to host life." Together, the binary pair spew enormous amounts of UV and X-ray radiation, "which would sterilize any surface that is exposed to it," so "life on any surface in the system is certainly not very likely." Still, Janson did not rule out the possibility that life could exist in subterranean oceans, matching ongoing speculation about basic life existing on Jupiter's moon Europa or Saturn's moon Enceladus.
That a planet exists in this star system is indeed surprising. Young stars have protoplanetary disks around them, from which planets eventually emerge. A hot star system like b Centauri, however, is not supposed to be conducive to planetary formation, owing to tremendous amounts of ultraviolet and X-ray radiation. This high-energy radiation "tends to destroy the disks in a very short time," and it was "thought that this wouldn't give planets enough time to form in the disk before it disappeared," [said Markus Janson, an astronomer at Stockholm University and the first author of the study]. Yet there it is -- a full fledged planet around the b Centauri system. [...] A neat observation is how the ratio between the masses of the star system and its planet closely matches that of our Sun and Jupiter. But that's where the comparison ends, as the scale of b Centauri is far vaster, as the planet is 10 times the mass of Jupiter and with an orbit that's 100 times wider. [...]
From an astrobiological perspective, Janson added that b Centauri is "possibly one of the worst places in the galaxy to host life." Together, the binary pair spew enormous amounts of UV and X-ray radiation, "which would sterilize any surface that is exposed to it," so "life on any surface in the system is certainly not very likely." Still, Janson did not rule out the possibility that life could exist in subterranean oceans, matching ongoing speculation about basic life existing on Jupiter's moon Europa or Saturn's moon Enceladus.
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Binary Effect (Score:3, Interesting)
Re: Binary Effect (Score:4, Informative)
The "weight" is given as a mass, so that problem is easily solved.
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The "weight" is given as a mass, so that problem is easily solved.
OP says:
With a combined weight of roughly 10 Suns
Is the Sun a unit of mass? I thought we had solar masses. https://en.wikipedia.org/wiki/... [wikipedia.org]
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"A neat observation is how the ratio between the masses of the star system and its planet closely matches that of our Sun and Jupiter. But that's where the comparison ends, as the scale of b Centauri is far vaster, as the planet is 10 times the mass of Jupiter and with an orbit that's 100 times wider."
From this, it seems reasonable to conclude they mean 10 solar masses. However, the phrasing is truly dreadful, I completely agree there.
Re: Binary Effect (Score:2)
located 325 light-years from Earth and has a combined mass of nearly 10 Suns
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Earth refers to our planet and Sun (uppercase) refers to our sun. The Sun (uppercase) is a sun (lowercase) with one solar mass (by definition). A mass of 10 Suns (uppercase) is the same as 10 solar masses.
Re: Binary Effect (Score:1)
It's actually called Sol, which is our sun, referred locally as the Sun. The original world sol also means sun but if we are going to be pedantic the proper name is Sol which is why we say solar instead of sunar.
The distinction also shows up with Earth to a less degree by using earth to refer to the ground.
In a distance galaxy is a plane where potentially being stand on earth while this rock revolves around a sun and if we were ever so brilliant as to stand there, we would call that sun, the Sun, but not So
Re: Binary Effect (Score:2)
Actually it means "sun personified" and as such is a better basis for a proper name and the likeliest reason it was adopted as the proper name when we began to more systematically study the stars.
It's like saying God, is the name of a deity. Monotheistic faiths all believe in a single god whom in writing they would call God or the God but each names this deity slightly different with bickering over languages even in some sects. God is not this diety's name but they are astronomers and like physicists they s
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Except that the proper name is not Sol, but Sun.
It is only called Sol in (some) science fictions.
Re: Binary Effect (Score:2)
This is just wrong. Otherwise we would not call our system the Sol system or our sector the Sol sector. The fact layman terms dominate scientific language to a bastardized point, doesn't mean the most consistent proper name for our star is Sol.
Sci-fi uses the term because they draw more from actual scientific language.
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"In English, the Greek and Latin words occur in poetry as personifications of the Sun, Helios (/hilis/) and Sol (/sl/), while in science fiction Sol may be used as a name for the Sun to distinguish it from other stars. The term sol with a lower-case s is used by planetary astronomers for the duration of a solar day on another planet such as Mars."
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This is just wrong. Otherwise we would not call our system the Sol system or our sector the Sol sector..
Citation needed.
The International Astronomy Union, the scientific body that assigns celestial names , recommends that the Sun be called "the Sun". [iau.org]
We do not call the Solar System "the Sol System", we call it "the Solar System". Googling "the Sol System" all of links on the first page are either from science fiction, links to "solar system" as preferred usage, or references to its use in science fiction.
You are citing SF conventions as if they were scientific standard terms.
Re: Binary Effect (Score:4, Interesting)
Don't be so quick to dismiss the scifi writers -- they are leading the way, thinking about the future and solving vocabulary problems the rest of us didn't even know we had.
Let's imagine that a human is standing on Proxima b and wants to say that it's bright outside. Does that human say "it's a Proxima Centaurish day" or "it's a sunny day"? When the human wants to make a rudimentary clock, is it a "Proxima Centauri dial" or is it a "sundial"?
The IAU recommendation seems extremely short-sighted and poorly thought out for a bunch of smart astronomers.
When you're on a planet, or referring to a planet, use the term "sun" or "the Sun" to refer to the star the planet is orbiting. This would be similar to how "mother" or "Mom" refers to a person's parent. It's a relative term. Mothers have names, and stars have names, so when referring to a specific star, use a name like Sol or Proxima Centauri.
By the way, the same page you linked also refers to exoplanets. That's also very Earth-centric. Those exoplanets are just planets. If you put a human on one of those planets, does it become an exohuman? No, it's just a human on another planet. I don't call your mom an exomom, just because she's outside my immediate family unit. Using the term exoplanet this way is silly.
When enough people adopt a different convention than the IAU's current recommendation, making it official is just a vote away.
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Damnit, now I'm going to start referring to other people's mothers as "exomoms".
You see what you've done?
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We do not cal our system "Sol System".
And there is no "Sol Sector".
You are mixing up SF with reality.
doesn't mean the most consistent proper name for our star is Sol.
Correct. It does not mean the proper name is Sol.
But: the proper name is not Sol. It is Sun in english. Sonne in German. Sol in Italian/Spanish/Portuguise ... etc.
Our sun does not have a "scientific name" - get over it.
Re: Binary Effect (Score:2)
Thank you, that was pretty funny.
Anti-intellectualism at work I guess?
Re: Binary Effect (Score:2)
The IAU refers to it as "the Sun", not Sol.
The solar mass is for measuring masses relative to *the* The Sun, not just *a* The Sun. It would remain useful in other solar systems, eg "Wow, the sun at our destination is large, and has mass of 3.7 solar masses." (I won't even try to sub
Re: Binary Effect (Score:2)
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Fair enough.
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I blame the colloquial conflation of weight (force) and mass on George Dvorsky from Gizmodo.
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It probably formed elsewhere and was captured (Score:3)
or its currently being flung out of the system because a gas giant at 52 billion miles out is seriously pushing the bounds of plausibility for it being able to form there.
Re: It probably formed elsewhere and was captured (Score:3)
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Re: It probably formed elsewhere and was captured (Score:2)
It's fucking huge to be captured but flung out seems possible.
However both seem problematic. If it's a capture, then you are suggesting it was a rogue planet? Don't know the age of this system but seems superbly impossible an old enough system ejected such a large body and then it was captured.
Likewise, it's a gas giant, so if it was closer and flung out, it should of been stripped of its gases when it was much closer.
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"Likewise, it's a gas giant, so if it was closer and flung out, it should of been stripped of its gases when it was much closer."
Perhaps it started out as a brown dwarf and thats exactly what happened.
Re: It probably formed elsewhere and was captured (Score:2)
hmm... interesting thought.
Hope to hear more about this system and purposed reasons for it's nature.
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How much closer do you think it was? And why do you think that?
Jupiter has not, probably been much closer to the Sun than about 4 AU, before a resonance interaction with Saturn and the "ice giants" started to drag it out again to it current 5.2~5.7 AU ; I've never seen anyone claiming significant mass loss for Jupiter.
I'd have to do some checking, but I don't think there's much ev
Details! (Score:5, Informative)
While some summaries lack detail, here we learn not once but twice that the b Centauri (or B Centauri, or Beta Centauri but who's counting) stars are 10 times the weight of our Sun, and that this new planet is 10 times the weight of Jupiter. Highlighting these numbers on the offchance someone missed them in the summary.
Not weight, mass (Score:2)
The distinction between weight and mass is rather important here.
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Which is a substantial difference, but not of great importance to the actual story here.
Re: Details! (Score:2)
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There is a reason that boring "telephone number" designations are used to identify stars in the formal literature, and you've nicely illustrated why. It's also why Henry Draper compiled his catalogue of bright stars, their positions, motions, colours etc in about 1920.
b Cen (AB)b (Score:2)
C'mon, can we have a naming system that doesn't look like C++ code?
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C'mon, can we have a naming system that doesn't look like C++ code?
Can we have a C++ naming convention that doesn't look like astronomical nomenclature?
Hey! (Score:2)
That's not a nice way to talk about your mom!
And choirs... (Score:1)
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Not every place has to be intelligently designed. There are plenty of shithole planets. No people can live there, but who knows about other life forms?To each their own. Hey, people live in Detroit.
Why Jupiter did not go nova? (Score:2)
Looks like even 10 times Jupiter mass is not enough to trigger nova. That is the nugget of I can extract from this messy summary.
Re: Why Jupiter did not go nova? (Score:2)
A nova is a transient explosive event caused by a dwarf star 'stealing' gas from it's companion. Once it builds up a critical mass ... boom! Jupiter is too far from the Sun to gravitationally steal material.
The proper question might be: If Jupiter is experiencing fusion in its core, at what point should we condider it to be a star?
Re: Why Jupiter did not go nova? (Score:4, Funny)
When it gets nomination for Best Supporting Actor in a Dramatic Series.
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If you have read that numerous times, and not been able to detect each time that this claim is pure fiction, then you need to re-evaluate either what you are reading, or how you are classifying what you read into fiction or non-fiction.
This is true. however, this ...
This is not a secure deduction from that statement.
Part of the energy budget of any plan
In other news, Italy is fining this planet (Score:3)
...For existing in contravention of known physics principles. The planet's response is that it will no longer serve the Italian market.
Just a thought (Score:2)
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Remember Shoemaker-Levy 9 and it's impact damage on Jupiter. Scale that up by a few billion fold ...
Send... (Score:2)
Send the crew of Dark Star. That's their job, let them do it.
Does it have moons? (Score:2)
Probably never be able to see moons from this far away, but that thing probably has a bunch of moons.
Nature says boo (Score:2)
Everytime someone says something should not happen naturally or is impossible to happen naturally, natures tends to throw a wrench in things.
Does not matter if it was formed in the solar system or was captured by the binary stars. It happens, it exists, and it happened naturally (unless you think there are some aliens using huge planets as a bowling ball).
Re: Nature says boo (Score:2)
Just goes to show the fractal nature of reality. The Dunning Kruger effect exists within the individual and it can exist at scale in a scientific field too.
That's kind of the story of science, isn't it: a continual realization that what we don't know can fill libraries.
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Which is why scientists do not tend to say that sort of thing. Extremely cautious people, scientists.
Journalists, on the other hand, say such things six times before breakfast.
terracentric (Score:2)
"...the binary pair spew enormous amounts of UV and X-ray radiation, "which would sterilize any surface that is exposed to it"..."
Yeah, I guess if "life" is only defined by whatever you learned in what, freshman biology class?
I understand that in our chemistry, such levels of incoming energy would be destructive to things like proto-amino acids and such.
However, I think there's an argument to be made that ANY system in which there is incoming energy it's conceivable that either local conditions could step i
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From a "life" point of view, the estimated age of the system at about 15 million years doesn't leave a lot of time for life to develop.
Prospectively, with several thousand times the luminosity (energy output) of the Sun from about 10 time it's mass, the star is going to run out of energy in about 1% of the lifetime of the Sun. Call it 50 million years, tops.
That is the sort of time it took for the Earth to go from post-Moon-forming impact magma ocean to maybe having so
The un-paywalled paper. (Score:4, Informative)
Abstract :
Planet formation occurs around a wide range of stellar masses and stellar system architectures. An improved understanding of the formation process can be achieved by studying it across the full parameter space, particularly toward the extremes. Earlier studies of planets in close-in orbits around high-mass stars have revealed an increase in giant planet frequency with increasing stellar mass until a turnover point at 1.9 solar masses, above which the frequency rapidly decreases. This could potentially imply that planet formation is impeded around more massive stars, and that giant planets around stars exceeding 3 solar masses may be rare or non-existent. However, the methods used to detect planets in small orbits are insensitive to planets in wide orbits. Here we demonstrate the existence of a planet at 560 times the Sun-Earth distance from the 6-10 solar mass binary b Centauri through direct imaging. The planet-to-star mass ratio of 0.10-0.17% is similar to the Jupiter-Sun ratio, but the separation of the detected planet is ~100 times wider than that of Jupiter. Our results show that planets can reside in much more massive stellar systems than what would be expected from extrapolation of previous results. The planet is unlikely to have formed in-situ through the conventional core accretion mechanism, but might have formed elsewhere and arrived to its present location through dynamical interactions, or might have formed via gravitational instability.
Upthread, robi5 got caught up by the naming. Literally the first line of the actual paper states "b Cen [not-equal-symbol] [Greek lower-case beta symbol] Cen". Which is the sort of thing that makes reading the paper essential, and makes reading the journalism utterly superfluous.
zkiwi34 asked about previous studies. Obviousl not in TFS ; I haven't wasted my time reading the journalism ; page 3 of the 34-page paper would have informed him (?, whatever) that
Such "pre-recoveries" are common - looking for them is SOP (Standard Operating Practice) when you find something interesting. No surprise what so ever that they had done this - it one of the first things the referees would have looked for.
None of the commentators wondered about the age of the system. Fair enough - it wasn't high on my list of questions.
Young, but with a luminosity of several thousand times that of the Sun, but only about 10 times it's mass, you can be pretty sure that it's less than a hundredth of the Sun's age. Another few million years and our cockroach inheritors might see a nice planetary nebula, or even a supernova.
This bears upon 140Mandak262Jamuna misconception about the Jupiter "turning on", and my explanation of the influence on primordial (sometimes also called "formation") energy, and how it takes time to leak away. For a 4.5 billion year old "Planet 9 (Brown & Batigyn 2016)" that leads to surface temperature estimates in the order of 100 K, but for a 15 million year old planet (the observed one under discussion) ... well, in the words of the paper :
Darkness (Score:2)
"Light thinks it travels faster than anything but it is wrong. No matter how fast light travels, it finds the darkness has always got there first, and is waiting for it" --Terry Pratchett (b. 1948)