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More Than Half of Kepler's Giant Exoplanets Were False Positives
StartsWithABang writes: By surveying an area of the sky containing over 150,000 stars visible to it, the Kepler satellite monitored each one over a multi-year period looking for periodic changes in brightness. Thousands of planetary candidates emerged via the transit method, where periodic dips of 3% or less were noted with regularity. However, a follow-up study has come out on the giant exoplanets, finding that over 50% of them aren't giant planets after all, but wound up being eclipsing binary stars. Perhaps our lone star Solar System is the oddity, after all.
"A fanatic is one who can't change his mind, and won't change the subject." -- Winston Churchill
That they are actually space-faring species building Ringworlds so they can use their Sun as a giant motor?
We all live in a lone star state, even those of us who don't live in Texas.
When you search for positive responses you get a lot of false positives. You should search what systems have no planets before searching the ones that could have one.
If you scroll down on TFA, there is a review of "Just Cause 3".
Even if 99% of the 2000+ exo-planets are not exo-planets, that's still 20 detected. Which isn't half-bad considering how long we've been seriously (space based telescopes etc) looking for them.
The conclusions in the article are weird to me. They are saying 52% of the exoplanets may not be exoplanets for this Kepler system example. Even if that holds, given the 2000+ exoplanets, if 48% are still probably exoplanets, that's 960 of them.
I'm assuming that Wikipedia's exoplanet count is sort-of right, and that it hasn't been already halved because we think 50%ish of them are probably other things.
They are "false positives" in the sense that the stellar companion may be a small star or a brown dwarf instead of a "planet". But the distinction between a "big hot gas giant" and a "brown dwarf" is fairly academic, in particular if you're concerned with things like habitability.
We still have too little data to guess whether our planetary system is special. Transits and Doppler wobbles are being detected in only a small fraction of the stars we observe. One reason is time: it takes an a few orbits to establish a pattern. So it's only natural that most of the systems we've found have been compact. They're they low-hanging fruit. It will take a bit longer to get a good statistical understanding of the proportion of less compact systems.
So someone comes up with a list of things that might be planets, then someone does further analysis and finds out that some aren't. Even (gasp) 52% of them! Science must therefore be useless.
No, that's how science works -- you do an experiment, examine the results, then refine your experiment. Or someone else does. Repeat ad nauseum.
So what? We only need one exoplanet capable of supporting life. And we will not even need that for decades, more likely centuries, possibly millenia.
Our first co-location effort is far more likely to be a world (or moon) in our solar system where humans live in a contained environment while terraforming the rest of the world. The transit time and complexity in getting seeding life forms there is literally astronomically less than trying to do that on a world in another solar system.
The only exceptions I could see where we might need to try the interstellar travel earlier would be if the exoplanet turned out to be so suited to our needs that we could just show up, or if it already had intelligent life and we established communication.
But realize that right now, we haven't sent so much as a rock even a sizable fraction of the way from here to Proxima Centauri, much less to a world with an exoplanet.
The "Giant science lever" settings guide.
Republican - Cite crappy statistics.
Democrat - Cite the fact the launch vehicle was Government funded.
Socialist - Cite the fact that the mission is peaceful and Government funded.
Libertarian - Cite the fact that you can choose if you want to read the article or not.
Capitalist - Cite the fact that the planets are new markets just waiting for buy refrigerators and huge untapped market.
Old Slashdot - Cite the fact that the featured article is kinda crappy, has crappy thinking, and that in your day you could have figured this out on an HP-35 quicker and more accurately, but you have used your HP-35 as a controller for a Beowulf cluster of MIPS processors you desoldered from old crappy routers.
New Slashdot - Cite the fact that citing facts is a micro-aggression against everyone else who might disagree with any of the facts, and complain that MIPS is unfairly represented and RPN is an elitist system hardly better than the slide-rules which killed trees that it replaced. Start the reply with "TLDR - Micro-aggressions from old calculator RPN using nerds harmful to community cohesiveness."
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I doubt if it was even close to 100%. So it should be expected that follow-up surveys would help to start sorting out the false positives. That's the way science works.
In other words, this is news?
A better success rate that your fucking articles, you woad-smeared fixie-riding bald beardy bastard.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Kepler has always required an independent check before moving a candidate exoplanet (with only Kepler data) to a confirmed exoplanet. That's why there are always a lot more Kepler candidates than confirmed exoplanets. From Wikipedia:
I think you are all missing the point here: there is a problem with our understanding of how solar systems evolve because we cannot explain the existence of closely orbiting solar-massed (or near solar-massed) object. That's the meaning of this discovery not the reduced planetary count -- which has caveats upon caveats of reasons why this is anticipated.
In my field of science, having a lead-finding system that returns a 50% hit-rate after confirmation is better then I've ever encountered. I'd say that this is an extremely impressive result.
If an experiment works, something has gone wrong.
In Soviet Russia, something about Natalie Portman forgot YOU!
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
What if it's impossible for life to form in a binary star system? That would change the probabilities of alien life quite a lot, wouldn't it?
No, the conclusion isn't that half of Kepler's giant planets are false positives. It's that the population of "Kepler Objects of Interest" is full of things that aren't planets. Because the transit method only gives the size of an object and not the mass, KOIs aren't considered planets until RV followup has been done. Kepler's population of planets are still planets.
Given the size of the cosmos (think: big. Really big), I don't think we're that unique.
It's terribly incorrect, to say, as the summary says, "Perhaps our lone star Solar System is the oddity, after all" - to the point of blunt stupidity.
Kepler's transit method will find some exoplanets, or at least the signs that something is worth taking a closer look at, but it also relies on a system's elliptical plane being aligned just so such a large exoplanet can cross the path of the star - in other words, we have to be able to see that plan edge-on. This reduces the likelihood of practically using this method to actually find something around 100-to-1, if it even exists.
A better link to the study is here buried towards the end of the OP link. I suppose it's too much to ask the OP to be a little more considerate and not link to his own site for self serving purposes?
Wat?
I can't even
Uah! TL;DR
Don't give Texas any ideas.
Suborbital [spaceflight] is the special olympics of spaceflight. - Rei
Does this mean there are lots more binary stars than we realized?
I agree. This is a general pattern I have seen in science writing and journalism that many writers do not understand the simple idea of percentage increase or decrease (which is probably why they did not decide to become mathematicians). This also applies to many approaches to trying to solve global warming or reduce energy consumption. It comes down to two misunderstandings: absolute vs relative scaling factors and something equivalent to Amdahl's Law. For scaling factors, if you have a large number and you reduce it by a small factor 2, 3, 4, etc... it is generally still large. For the Amdahl's Law problem, you do not try to optimize the section of your code that only takes a small fraction of your time. Similarly, one person cutting back on their carbon emissions has pretty much zero effect. Even if every person on Earth cut their carbon emissions to zero, you have not solved the main problem, which is carbon emissions from power generation. I am not saying people should not do their part, but we need to solve the big problems *first*. I have advocated for nuclear reactors for years. Of course, in places that are not seismically stable we can still use fossil fuels and have a very minimal impact. Of course, this is a different issue entirely, but it illustrates a general misunderstanding of percentages, fractions, scaling factors, etc....
Democrat - Cite the fact the launch vehicle was Government funded.
But then defunded to pay for entitlement programs.
New Slashdot - Get upvoted for your breitbart fueled SJW-calling fantasy.
FTFY
Kepler Discovers Many Close-Orbiting Binary Star Systems
I don't think they expected to find so many binary stars orbiting so closely together, so this is an interesting finding.
But so many of these giant worlds (or brown dwarfs, or even stars) are less than a tenth the distance to the main star as Mercury is from ours!
Even with half of Kepler's finds being false positives, that still leaves planets as being extremely common around starts. Earth is hardly an oddity.
Forget your password, AmiMojo?
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
My slide rule killed no trees. It is made of plastic. Actually, I never saw a wooden slide rule, except for the giant one that hung over the blackboard at the front of the classroom. All the others were made of plastic, metal, or bamboo.
It is a big number, but there's always the possibility that there are other glitches which could account for the remainder. Sunspots (on the distant star, not our Sun), flares on the distant star, variable stars, intervening objects in the hundreds or thousands of light years between us and the other stars, instrument glitches, I don't know what else, and of course I don't know which of these potential glitches have already been accounted for.