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Astronomers Discover Alien World Hotter Than Most Stars (vanderbilt.edu)

Science_afficionado writes: An international team of astronomers has discovered a planet like Jupiter zipping around its host star every day and a half, boiling at temperatures hotter than most stars and sporting a giant, glowing gas tail like a comet. From a report via Vanderbilt University: "With a day-side temperature peaking at 4,600 Kelvin (more than 7,800 degrees Fahrenheit), the newly discovered exoplanet, designated KELT-9b, is hotter than most stars and only 1,200 Kelvin (about 2,000 degrees Fahrenheit) cooler than our own sun. In fact, the ultraviolet radiation from the star it orbits is so brutal that the planet may be literally evaporating away under the intense glare, producing a glowing gas tail. The super-heated planet has other unusual features as well. For instance, it's a gas giant 2.8 times more massive than Jupiter but only half as dense, because the extreme radiation from its host star has caused its atmosphere to puff up like a balloon. Because it is tidally locked to its star -- as the moon is to Earth -- the day side of the planet is perpetually bombarded by stellar radiation and, as a result, it is so hot that molecules such as water, carbon dioxide and methane can't form there." The findings have been published in the journal Nature.

59 comments

  1. Serendipity, publish or perish by Anonymous Coward · · Score: 2, Insightful

    Simple enough : we get massive amount of data from scoped research as a side dish, and a trove of nameless PhD who've been told to publish or perish. I say : publish anything remotely interesting.

    But c'mon man, can't you find it a least puzzling and a new onlook on space the fact that the frontier between a star, a comet, and a planet becomes that much more hazy ?

    Can't you marvel at the idea of giant ball of proto plasma weezing around a sun with a trail behind ?

    And that all these findings are due to serendipity ?

    I diagnose you, sir, with a broken dream organ.

  2. Re:Simple question by Anonymous Coward · · Score: 1

    It's hot, so chances are if there are any purple alien chicks they're all nekkid.

  3. Simple answer by Anonymous Coward · · Score: 0

    Because it's there. Also, it's way cool. Oh wait, not so cool...

    Seriously though, just because something is there does not mean it should be mined, invaded, or paved over. Sometimes pure science is its own purpose - it might or might not give a practical benefit later, but you'll never know if you don't first do the science.

  4. Re:Simple question by Anonymous Coward · · Score: 0

    I might mod you down for be being incredibly boorish and unimaginative, but certainly not as a way to avoid answering your question; I can do that without modding you down. Did someone else win the science fair when you were 10 and you're still bitter about it?

  5. Re:Simple question by meerling · · Score: 2

    If everyone thought like you did, we'd still be in the dark ages.
    You never know what research will find, but because of all that research of no known future application was done, we have a world of computers, medicine, worldwide communication, and a multitude of other wonders.

  6. Re:Simple question by CSMoran · · Score: 4, Funny

    The ad hominem attacks will prove that I'm right and that this finding is utterly useless.

    Wait, so every time someone calls you names, that means your arguments become correct? I call your ad hominem and raise you a non sequitur.

    --
    Every end has half a stick.
  7. Amazing. by Gravis+Zero · · Score: 4, Funny

    With a day-side temperature peaking at 4,600 Kelvin (more than 7,800 degrees Fahrenheit)

    I think they finally found the homeworld of AMD processors. ;)

    --
    Anons need not reply. Questions end with a question mark.
    1. Re:Amazing. by Anonymous Coward · · Score: 0

      Worse - the homeworld of the Pentium 4

    2. Re:Amazing. by dinfinity · · Score: 1

      Your joke is old and outdated.

      AMD Ryzens run much cooler compared to their Intel counterparts, unless you want to void your warranty and delid your Intel CPU:
      http://wccftech.com/intel-core...

    3. Re:Amazing. by Gravis+Zero · · Score: 1

      It's just a joke. The only x86 chips I've used in the past decade have been AMD chips. I was disappointed when they added an equivalent of the IME and have begun seeking other avenues for processing.

      --
      Anons need not reply. Questions end with a question mark.
    4. Re:Amazing. by OhSoLaMeow · · Score: 2

      With a day-side temperature peaking at 4,600 Kelvin (more than 7,800 degrees Fahrenheit)

      I think they finally found the homeworld of AMD processors. ;)

      And here I was thinking that this planet withdrew from the Paris Accord.

      --
      They can take my LifeAlert pendant when they pry it from my cold dead fingers.
    5. Re:Amazing. by ACE209 · · Score: 1

      Your joke is old and outdated.

      Not here. My AMD is the only thing keeping me warm in the winter. :)

      --
      "we are all atheists about most of the gods that societies have ever believed in. Some of us just go one god further."
  8. So, the largest planet ever discovered? by Anonymous Coward · · Score: 2, Interesting

    If those numbers are correct and "density" refers to the mean density over the entire planet, then that would make this the largest planet ever discovered at 7.6 times the radius of Jupiter. As far as I can tell the record was HD 100546 b at 6.9 times the size of Jupiter. Odd that the neither the article nor the summary mentions breaking that record. In light of that, I have a suspicion that someone reported the numbers incorrectly and that it's only 1.8 times the mass of Jupiter. Maybe I missed it but I can't spot the actual mass or size in the article anywhere.

    1. Re:So, the largest planet ever discovered? by Anonymous Coward · · Score: 0

      I have a suspicion that someone reported the numbers incorrectly and that it's only 1.8 times the mass of Jupiter.

      And now I noticed that I made the exact same mistake that I accused TFA of making, but in the opposite direction :p

      I meant to say "1.8 times more than the mass of Jupiter", which is "2.8 times the mass of Jupiter".

  9. No water, CO2, or methane? No greenhouse gases? by Anonymous Coward · · Score: 0

    Good thing they don't have to worry about global warming.

  10. Trump - Make Planet Earth Hot Again! by davidshenba · · Score: 0

    We will overtake them by 2050 despite negative solar covfefe!

  11. Re:Simple question by TheOuterLinux · · Score: 1

    For certain AC's, yes actually, but no cares what an AC thinks. I've been having to deal with "ad hominem" each time I question an article that involves scientists, almost creepily so like I'm being watched by a certain person that doesn't have the balls to reveal himself/herself. The problem is, because of recent political decisions, anyone skeptical of a scientific claim almost automatically gets shunned without any actual relevant counter-argument (almost always "ad hominem"; perhaps, "non sequitur"). These people that get offended blindly support a field they clearly know nothing about and only take the time to respond in a way as to suggest they view the particular field as an ideology and therefore as a personal attack rather than as a science that doesn't need faith to defend itself, just people able and willing to respond with an ounce of intelligence. "I'm skeptical and here's why..." has become the new "I hate all [insert race]."

  12. Re:Simple question by JonnyCalcutta · · Score: 1

    Maybe because its one small step to understanding the universe and our place in it, and without all those potentially useless steps we'd be sitting in our cold caves eating dinosaur sushi. Maybe it will lead to nothing, or maybe our understanding of stars and planets will one day lead to better power sources (fusion/fission) or superconductors or communications or a new series of Survivor. Perhaps you think research works like Civilisation V, where you can view the tech tree and plan which advances you are going to get in the future, but it doesn't. Faraday didn't think- 'I'd like my ancestors to watch The Kardashians and heat up their popcorn in microwaves'. - he played around with potentially pointless experiments in the full knowledge that perhaps all he'd get out of it was a machine that made pretty sparks, but with the hope that it would lead him to something huge.

    And apart from all that - what do you think it actually cost? A few university researchers using a telescope that was already built?

    Honestly, Slashdot has turned into the playground of the Luddites. All that are left are the political stooges and a few of us lost geeks wandering around wondering what happened.

  13. Re:Simple question by Anonymous Coward · · Score: 0

    Darling, everything is useless.

  14. Re:Simple question by TheOuterLinux · · Score: 0

    AC, I would mod you up if I could. Platforms for healthy skepticism are very rare these days. All you did was ask a simple yet genuine question that should be allowed to remain for intelligent discussion. Unfortunately, 99% of Slashdotters take astronomy to heart, turning it into an almost religion and therefore start throwing stones, only to make those in politics we are all unhappy with right now, look no worse. The truth is, most people here are techies only and actually know very little of the subject they are trying to defend.

    But to answer your question, it does not nor ever will affect anyone at all. On top of which, the word use of "alien world" is cleverly used to suggest life, which is one of very few things left in this field driving people to invent and try new things to answer questions we have had for thousands of years. There was a time in history in which our focus was on the physics of our own planet. But, fast-forward a few hundred years, we go to the moon and allowed conspiracy theorists to create curiosity around the same time because of things like Area 51 and because reality sucks. Cowboys are replaced by spacemen. Now, you have people trapped in theories that will never be proven, and it will only get worse because much like what we did during the Cold War, we will use that same hope to get us through these difficult times. Space centers know how important they are for creating a new generation of freethinkers and inventors and will push anything they can to keep going.

    But quick tip, don't use "...will prove I'm right..." because if you want to argue and not have ad hominem responses, you cannot take the high ground in a way that uses absolutes. Only those that already have a significant standing in a scientific community can do that, even though it looks crass. It makes it look like you have to defend something that you believe should be obvious to others.

  15. What does this have to do with Sun Microsystems? by TheOuterLinux · · Score: 3, Insightful

    Seriously. Look at the icons near the title.

  16. Re:Simple question by Anonymous Coward · · Score: 0

    Great troll. I almost thought you were serious for a second. I cracked up at the "ad hominem" part.

  17. Crematoria ! by Anonymous Coward · · Score: 0

    We have found the location for a new high-security prison. Just need some enterprenurial prison corporation to seize it before anyone else does...

  18. Re:Simple question by Tenebrousedge · · Score: 3, Insightful

    Your first issue is that you have conflated science and engineering. Your second issue is that you know little of either. Your ultimate issue is that you think like you write, and your writing is incoherent.

    You're also wrong about almost everything you say, but I'm not interested in pig-wrestling today.

    --
    Those who advocate genocide deserve every protection afforded by law, and none afforded by common human decency.
  19. Re:Simple question by Dunbal · · Score: 1

    In the long run we're all dead.

    --
    Seven puppies were harmed during the making of this post.
  20. Re:What does this have to do with Sun Microsystems by jfdavis668 · · Score: 1

    The planet is heated by SPARC processors.

  21. Re: Simple question by Anonymous Coward · · Score: 0

    It's not a great question because every single fucking article on slashdot now has this same stupid conversation. I guess it's a meta troll to make all of you defend science every time, but both the question and the defense are at this point BORING.

  22. Re:What does this have to do with Sun Microsystems by l20502 · · Score: 1

    Just there as a cool logo

  23. Re:Simple question by Tenebrousedge · · Score: 1

    Actually you are just a moron. Sorry to be the one to let you know. If you were qualified to be "skeptical" you would write a rebuttal paper and submit it for review. That goes double for anything involving modeling.

    Why don't you cure your skepticism with some facts.

    --
    Those who advocate genocide deserve every protection afforded by law, and none afforded by common human decency.
  24. Re:What does this have to do with Sun Microsystems by The+Grim+Reefer · · Score: 1

    No kidding. This is obvious about a Sun Macro system.

  25. Re:Simple question by Anonymous Coward · · Score: 0

    Yes, what possible advancements could come from the development of extrasolar detection methods and the associated technologies.

    Short-sighted moron.

  26. Re:Simple question by Anonymous Coward · · Score: 0

    That really depends on what you're skeptical about. If you're skeptical with regards to the efficacy of a new medication or treatments around brain elasticity, then I think that's very fair. If, however, you skeptical about gravity or climate change, and you're over the age of 18 and not asking for the purposes of research but to grandstand your own ignorance, then yes, you're a fucking moron.

    Additionally, calling you a moron does not on its own constitute an ad hominem. For example:

    Joe is an asshole and his argument is shit. This is NOT an ad hominem.
    Joe is an asshole and because of this all of his arguments are shit and not worth considering IS an ad hominem.

    Here's a good primer on the topic: http://laurencetennant.com/bon...

  27. Re: Simple question by Anonymous Coward · · Score: 0

    Because the heavens declare the glory of God, and our discoveries honor that.

    Yeah, I know someone will probably mod this down or make snide remarks out of ignorance, but at least you can't deny that I endorse scientific discovery.

  28. Re:Simple question by Anonymous Coward · · Score: 0

    Except, he didn't just "ask a question". He was attempting to be contrarian by asking a question he then answered (Can anyone explain the value of this study? I think not) and then began to martyr himself over the predictable, and justified, response to his being a twat about it. He's not looking for discourse, he's looking to be a prick and he shouldn't be surprised when he gets responses in kind. Had it been an honest question, he'd still get some of the usual internet message board fuckery, but he'd also get some honest answers about the value of extrasolar research and, more importantly, the advancement of the technology behind the equipment used and how that applies to a number of other areas.

  29. If it's tidal locked like our moon... by The+Grim+Reefer · · Score: 1

    I wonder if it was formed the same way. Something really big must have impacted that star prior to the start of the fusion reaction.

    1. Re:If it's tidal locked like our moon... by Hognoxious · · Score: 1

      I wasn't aware that impact formation was a necessary or a sufficient condition for tidal locking to occur.

      --
      Confucius say, "Find worm in apple - bad. Find half a worm - worse."
  30. Re:Simple question by Anonymous Coward · · Score: 0

    Can anyone explain the value of this study?

    We're still stuck in the theory stage of planetary system formation. Having more data points helps us weed out the bad theories.

    We don't even know how common planets are, at this point. They seem common, but how common?

    Considering that nearer solar systems are theoretically reachable in the future, maybe we should learn.

  31. Re:Simple question by JonnyCalcutta · · Score: 1

    AC, I would mod you up if I could. Platforms for healthy skepticism are very rare these days. All you did was ask a simple yet genuine question that should be allowed to remain for intelligent discussion. Unfortunately, 99% of Slashdotters take astronomy to heart, turning it into an almost religion and therefore start throwing stones, only to make those in politics we are all unhappy with right now, look no worse. The truth is, most people here are techies only and actually know very little of the subject they are trying to defend.

    In a written only medium its can be very hard to separate a real troll from a sceptic who is just rude. Therefore if someone genuinely wants to ask a question they should probably be careful not to pitch it in a form that looks like a troll. Also don't ask the same question in every single science post.

  32. Re:Simple question by TheOuterLinux · · Score: 1

    I mention that people are afraid to question because of looking ignorant and being paired with those in politics. You site an aip page on global warming, which has nothing to do with astronomy or anything I've said. You're the actual moron and doing nothing but proving my point. IF you are capable of doing anything but name calling and misplaced logic, fee free to stop by again. I would love to hear a counter-argument involving the ACTUAL subject at hand, astronomy if you forgot and my two-cents covers a lot more than global warming in this particular thread, to which I don't dispute at all. So, what would the point of a rebuttal be in the first place? OP and I argue its value, not its validity. But as a side-note, if alluding to global warming is all you have in your arsenal for every time someone questions research, then it's just you and everyone else in the logical fallacy club trying to not look ignorant, as if political correctness has anything to do with science; it's a social issue and tell your people to not bring their baggage into science. Your "Think of the children" mentality won't get you far in any real science community. All your moronic millennial culture are capable of doing is turning facts into trends with absolutely no understanding of how it works, save a Bill Nye episode on Netflix and whatever Facefarm throws at them every morning. I would NEVER want to cure skepticism. No one that cares about science ever would. Faith in science is an oxymoron and the ideologies it's creating, as if a religion, are very dangerous. You are supposed pursue knowledge, you don't just let it be handed to you.

    "The statements on this site represent the views of the author and are not positions endorsed by the American Institute of Physics." That's at the bottom of your sited page by the way. I spend 7.5 years in college and you spend 7 seconds googling. Congrats.

  33. Re:Simple question by TheOuterLinux · · Score: 1

    This is first time I'm seeing it. Looks like a genuine concern to me, and I probably wouldn't be "all over it" if it wasn't for the much worse responses that actually do seem to prove AC's point. A lot of name calling and no real substance.

  34. Re:Simple question by Anonymous Coward · · Score: 0

    I spend 7.5 years in college

    Yet somehow you missed learning about the Argument from Authority.

  35. Re:Simple question by Anonymous Coward · · Score: 0

    The company I work at uses some hardware and software derived from the spectroscopic equipment used in exoplanet hunting. If we didn't have access to the software and equipment that is available from vendors because of that, we would have to employ another full time PhD and engineer. And it is not like we would have redeveloped the same stuff, because more likely we would have spent more money to use a less useful derivative of a different technique to cut corners and save time, and the company doesn't sell or publish the analysis methods, only the results. I also know we're not the only company using this equipment.

    I've posted this before and similar examples from companies I've worked for before. But you'll quickly realize that most of these posts are trolls, that no amount of explaining and giving them examples will stop them from shouting absolutes like "nothing useful will come from this." Of course there is plenty of room for the much more subtle discussion of whether usefulness is worth the cost and if there are more efficient ways to get the same results. But no, there are plenty of people on Slashdot that purposely post the same wrong things over and over again, completely disregarding the replies they got the last time. They're looking for a reaction, and often lying by saying "No one ever been able to show this is wrong, they only provide ad hominen attacks" when the reality is that months or even years ago the people with informative replies gave up wasting time.

    Repeating something until other viewpoints get too tired of replying or putting effort into replying properly is not some sort of proof that one is correct, or that the other side is wrong.

  36. Re:Simple question by JonnyCalcutta · · Score: 1

    Actually, given that it had all the definitions of a troll I would say that the 'good answer' to name calling ratio was pretty good. *shrug*

  37. Re:Simple question by drinkypoo · · Score: 1

    Not me, I'm going to live forev

    --
    "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
  38. Re:Simple question by Tenebrousedge · · Score: 1

    My apologies for assuming that you were a more specific brand of moron.

    Frankly you're not really worth the time to do more than insult you. There's not really an argument to be had about whether or not you see the value in any particular bit of research. There isn't actually any way to value pure knowledge either.

    This particular paper does not present new techniques so far as I have read, but analyzing spectroscopic data is a fairly interesting topic on its own. I assume you've read it, of course. Must be old hat to you, right? More generally, studying exoplanets provides information on what types of star systems are able to be formed, and gives us some insight into the formation of our own solar system. If you're searching after a practical application however, again, the fault is with your own understanding: that's not the goal of research.

    'Physics is like sex: sure, it may give some practical results, but that's not why we do it.' — Feynman

    (blah blah millennials blah blah political correctness blah blah my age is greater than my IQ)

    --
    Those who advocate genocide deserve every protection afforded by law, and none afforded by common human decency.
  39. Alien World? That the f**k is that? by Eloking · · Score: 1

    Seriously /. editor, what the f**k is that? Is "exoplanet" that hard to use? Even the cited link use the correct term.

    --
    Elok
  40. Re:Simple question by MightyYar · · Score: 1

    I find it pretty far fetched that this research would lead to us having a new type of semiconductor for example.

    But that's a problem with your lack of imagination, not a problem with people trying to advance human understanding of the natural world.

    --
    W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
  41. Re:Simple question by TheOuterLinux · · Score: 1

    I wonder what would happen if you were capable of formulating arguments without insults? Let's go to the Neighborhood of Make Believe (ding ding): "If you were qualified to be "skeptical" you would write a rebuttal paper and submit it for review. That goes double for anything involving modeling. This particular paper does not present new techniques so far as I have read, but analyzing spectroscopic data is a fairly interesting topic on its own. I assume you've read it, of course. More generally, studying exoplanets provides information on what types of star systems are able to be formed, and gives us some insight into the formation of our own solar system. If you're searching after a practical application however, again, the fault is with your own understanding: that's not the goal of research."

    You'd think an educated human being wrote that. Why would that have been so hard for you to do in the first place?

    Or better yet, just shorten it to: "Studying exoplanets provides information on what types of star systems are able to be formed, and gives us some insight into the formation of our own solar system." But instead, you decided to go with the third grade name calling tactic. Why should I or any mature adult take anything you say seriously when you do that?

  42. Re:Simple question by Tenebrousedge · · Score: 1

    So you read some slashdot story on a scientific topic until you get to a poorly-written rant which promotes "skepticism", which is a dog whistle for various anti-science types. Complaining about the scientific establishment, questioning the value of research and astronomy in general, and talking up "free thinkers" are the hallmarks of the physics crank. This person does not ask what the significance of the research is, they instead write paragraphs about how the useless the research is. This is not a person seeking to remedy their ignorance.

    I'll retract most of my criticism of your scholarship. I do think that your style of writing is poor, and that you might want to get that young-person prejudice looked at. I'm in my 30s and was raised in rural Alaska; whatever qualities you imagine I have are unlikely to be applicable. And yes, I often belittle the intelligence of others on this forum. I'll consider your criticism on that score.

    The paper, if you haven't read it, is available on the arxiv. (You may also want some background on echelle spectrometers). It does not go into great detail about the formation of star systems generally; it's focused on the subset of star systems with these "hot Jupiters". These systems are interesting because [1] they're big compared to rocky planets and therefore more easily found and studied, and [2] they're almost the 'default' result of excess stellar material. We would expect Jupiter to form more or less where it is, and then migrate inwards closer to the Sun, gobbling up or ejecting the inner planets as it went. One theory is that it actually started to do so, but then was pulled back by Saturn. It's not extremely well supported as yet, but it's one of the more interesting developments in astronomy in recent years. A critical review from the arxiv.

    Generally speaking, the solar system doesn't look like how our models think it should. We ask: why? How much did the peculiar configuration affect the origin of life on Earth? Where else in the universe might we find conditions similarly hospitable for life? This discovery is a very small step towards answering these questions. They are, of course, of no practical use, now or in the future, but there's nothing wrong with the pursuit of knowledge for its own sake.

    --
    Those who advocate genocide deserve every protection afforded by law, and none afforded by common human decency.
  43. Re:Simple question by Anonymous Coward · · Score: 0

    Please stop replying to that bot.

    It posts the exact same thing, word for word, in each and every story posted to Slashdot with the "Science" tag. Without fail.

    It's a bot, plain and simple. Mod it as troll if you wish, but drawing attention to it isn't helpful for anyone.

  44. Re:Simple question by Anonymous Coward · · Score: 0

    "until you get to a poorly-written rant which promotes "skepticism", which is a dog whistle for various anti-science types"

    Exactly. When reason fails, contemptuous dismissal is simply the most expedient option. It wasn't dangerous, homogenizing group-think, it was a spade being identified as such, nothing more.

    If it stings to be called an moron, stop defending them. "How does this finding affect anyone at all? Nobody can live there..." is that really the stance you want to defend? Note it got modded as troll, because people have a hard time believing someone would even *actually* say something that stupid.

  45. Re:Simple question by Anonymous Coward · · Score: 0

    Also it's not like the set out to find this planet specifically.

    This discovery is the result of generic "find and classify exo-planets" research, which is useful in that understanding the way planets form and evolve over time will provide insight into how we can better tune our own planet for optimal quality of life in the long run (like how knowing that there will be winters allows you to build heating and insulation into your house instead of being surprised by how cold it gets every year, just on a much lager scale), but to understand the properties of planets we need to study lots of them so finding as manny as we can is a sensible early step.

    Complaining that this planet isn't exploitable is a lot like complaining when the geologist you hired to survey your building sight shows you a cool rock he found while doing the survey. On some level you just have to accept that people who find unusual things will sometimes show them off even if that thing isn't what they're actually looking for.

  46. Re:Simple question by OrangeTide · · Score: 1

    The pursuit of knowledge and confirmation and direct application of physical theories is not valuable to you?

    --
    “Common sense is not so common.” — Voltaire
  47. Re:Simple question by sysrammer · · Score: 1

    Some people do not have the curiosity level that let's them understand your arguments. They do and/or can not believe in the utility of pure research.

    So I'd say you're just pissing against the wind (note for ESL folks: a colloquialism, not an ad-hominem).

    sr

    --
    His ignorance covered the whole earth like a blanket, and there was hardly a hole in it anywhere. - Mark Twain
  48. Re:Simple question by TheOuterLinux · · Score: 1

    Thank you for the change of tone and finally saying something worth biting into. That's all I ever really wanted. Write like you are doing now next time instead of insults. I like seeing real discussions; I have no need to be right as long you can throw a good argument "punch," but I do have a problem with name calling when we are all adults.

  49. hotter than the *surface* of the Sun by mcswell · · Score: 1

    "is hotter than most stars and only 1,200 Kelvin (about 2,000 degrees Fahrenheit) cooler than our own sun." Well, that all depends on where you take the Sun's temperature, or the temperature of any star. They're all hugely hotter near their core, because that's where the fusion is going on--as in 15 million degrees Celsius (or Kelvin, at that temp the diff between Celsius and Kelvin is negligible) at the Sun's core. (The Sun's corona is also much hotter.) I don't know whether the core of this planet is hotter or cooler than its surface, but it's presumably not hot enough to cause fusion. If it were hot enough for that, by definition it would be a star, not a planet.