There Could Be Many More Earth-Sized Planets Than Previously Thought (phys.org) 43
New findings from a team using the international Gemini Observatory and the WIYN 3.5-meter Telescope at Kitt Peak National Observatory suggest that Earth-sized worlds could be lurking undiscovered in binary star systems, hidden in the glare of their parent stars. As roughly half of all stars are in binary systems, this means that astronomers could be missing many Earth-sized worlds. Phys.Org reports: Earth-sized planets may be much more common than previously realized. Astronomers working at NASA Ames Research Center have used the twin telescopes of the international Gemini Observatory, a Program of NSF's NOIRLab, to determine that many planet-hosting stars identified by NASA's TESS exoplanet-hunting mission are actually pairs of starsâ"known as binary starsâ"where the planets orbit one of the stars in the pair. After examining these binary stars, the team has concluded that Earth-sized planets in many two-star systems might be going unnoticed by transit searches like TESS's, which look for changes in the light from a star when a planet passes in front of it. The light from the second star makes it more difficult to detect the changes in the host star's light when the planet transits.
Using the 'Alopeke and Zorro instruments on the Gemini North and South telescopes in Chile and Hawai'i, respectively, the team observed hundreds of nearby stars that TESS had identified as potential exoplanet hosts. They discovered that 73 of these stars are really binary star systems that had appeared as single points of light until observed at higher resolution with Gemini. "With the Gemini Observatory's 8.1-meter telescopes, we obtained extremely high-resolution images of exoplanet host stars and detected stellar companions at very small separations," said Katie Lester of NASA's Ames Research Center, who led this work. Lester's team also studied an additional 18 binary stars previously found among the TESS exoplanet hosts using the NN-EXPLORE Exoplanet and Stellar Speckle Imager (NESSI) on the WIYN 3.5-meter Telescope at Kitt Peak National Observatory, also a Program of NSF's NOIRLab.
After identifying the binary stars, the team compared the sizes of the detected planets in the binary star systems to those in single-star systems. They realized that the TESS spacecraft found both large and small exoplanets orbiting single stars, but only large planets in binary systems. These results imply that a population of Earth-sized planets could be lurking in binary systems and going undetected using the transit method employed by TESS and many other planet-hunting telescopes. Some scientists had suspected that transit searches might be missing small planets in binary systems, but the new study provides observational support to back it up and shows which sizes of exoplanets are affected. The researchers report their findings in a paper via arXiv.
Using the 'Alopeke and Zorro instruments on the Gemini North and South telescopes in Chile and Hawai'i, respectively, the team observed hundreds of nearby stars that TESS had identified as potential exoplanet hosts. They discovered that 73 of these stars are really binary star systems that had appeared as single points of light until observed at higher resolution with Gemini. "With the Gemini Observatory's 8.1-meter telescopes, we obtained extremely high-resolution images of exoplanet host stars and detected stellar companions at very small separations," said Katie Lester of NASA's Ames Research Center, who led this work. Lester's team also studied an additional 18 binary stars previously found among the TESS exoplanet hosts using the NN-EXPLORE Exoplanet and Stellar Speckle Imager (NESSI) on the WIYN 3.5-meter Telescope at Kitt Peak National Observatory, also a Program of NSF's NOIRLab.
After identifying the binary stars, the team compared the sizes of the detected planets in the binary star systems to those in single-star systems. They realized that the TESS spacecraft found both large and small exoplanets orbiting single stars, but only large planets in binary systems. These results imply that a population of Earth-sized planets could be lurking in binary systems and going undetected using the transit method employed by TESS and many other planet-hunting telescopes. Some scientists had suspected that transit searches might be missing small planets in binary systems, but the new study provides observational support to back it up and shows which sizes of exoplanets are affected. The researchers report their findings in a paper via arXiv.
hmmm (Score:4, Funny)
still no stargates ??
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Perhaps not, but _lots_ of dark matter. This kind of discovery is why I've distrusted the exotic dark matter theories. In particular, we're finding a lot more exoplanets than anticipated. They may have formed _without_ stars. If that's true, I could explain the "dark matter" problem with quite normal, baryonic matter.
Baryonic dark matter [Re:hmmm] (Score:4, Insightful)
It's a hypothesis worth considering. But the reason cosmologists usually discard the hypothesis that dark matter is baryonic (ie, ordinary matter) is there there doesn't seem to be any mechanism for forming large amounts of heavy elements in the early universe. If dark matter were planets (or even gravel), that would mean that elements heavier than hydrogen and helium far outmass the amount of hydrogen in the universe. That's hard to credit. And then, why are stars mostly hydrogen, if there's so much non-hydrogen content in the galaxy?
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Even multiplying the number of estimated black holes by a factor of a 1000 would not explain the observations. Whatever it is, it isn't baryonic matter.
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> If dark matter were planets (or even gravel), that would mean that elements heavier than hydrogen and helium far outmass the amount of hydrogen in the universe.
Because hydrogen and helium would evaporate to space from the surface of such bodies? I think not if they are cold enough. Cold enough, at or slightly below the 2.5 degrees K of the microwave background radiation at the surface, would suggest that even modest evaporation over the age of the universe would cost them very little mass.
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No, it's the fact that we know that stars are hydrogen and helium, and we know that the total mass of dark matter exceeds the total mass of stars (and interstellar medium, which is also mostly hydrogen) in the universe. So, if dark matter were heavy elements, there must be much more mass of heavy elements than hydrogen and helium. Where did this come from? Why did it not settle into stars, where we would be able to see it?
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Extrapolating that, the total amount of matter in planets, in the entire galaxy would be less than 1%.
As I recall it, the estimates for the "missing" dark matter is around 30% of all matter...That seems above the ability of a couple of planets to explain...
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Extrapolating that, the total amount of matter in planets, in the entire galaxy would be less than 1%.
Perhaps your extrapolation is the error. Perhaps rogue planets are far more common than we know - either because they more frequently form on their own or because they form more frequently around stars systems and are simply tossed out of orbit.
I get that SOMETHING is exerting gravitational influence, but I don't like the knee-jerk reaction in astronomy that seems to be: if our math results in something other than what is observed, we don't question our observation or our understanding of the math - we just
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I'm not saying that it dark energy and/or matter don't exist,
As far as we can tell at the moment: they do exist, we just don not know what it is.
but until it becomes something more than a mathematical placeholder to make the math work my inclination would be more towards there being something fundamentally wrong with our math.
Unlikely.
It certainly has happened before (eg, Newtonian physics vs Relativity).
Bad example. Newton was not wrong. Neither is Einstein as far as we know.
For most things relevant, GPS
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For most things relevant, GPS a note able exception, you can use for everything in our solar system simply the classical Newtonien formulas: that is why every school kid learns them in school.
Indeed - but that doesn't mean the equations aren't wrong - they just happen to be close enough to correct that they can still be used. Sort of like saying that the value of PI is 3.14 - its not strictly correct but its close enough that it works well enough in most cases.
Einstein's equations are better (eg, they work in more cases), but they break down at the quantum level for sure, meaning they likely are again, simply "close enough". There's no guarantee that they don't also break down at much larger s
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Or, perhaps, erroneous about the conclusions from the observations. Math is easily verified. Extrapolations about cosmological scale skew in the Hubble constant, or about the distance and correlated luminosity of objects billions of years old is another source of potential skew in the theories.
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but where is everybody? (Score:4, Interesting)
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With lack of complete data, scientist will often take what we do know and figure it is somehow within the first Standard Deviation of the mean. This makes sense, as the chance something we find common is probably what it is like elsewhere.
The earth is around 4.5 billion years old. While it took less than a billion years for life to start, It took 3 billion years for multi-cellular life It nearly took an other billion years after that for Animals to appear on earth. Which were mostly just sponges. And inte
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I would imagine you aren't far from wrong. But considering how we're just now beginning to detect earth-like planets in other solar systems, we have no idea how large the possible field is for earth-like life, even of the slime variety, to begin developing. That number could be infinitesimally small, or so gargantuan it couldn't really be comprehended, or anywhere in between.
If we suspect it's a massive number of earth-like planets (goldilocks zone, liquid water, fluctuating seasons, etc.), then it only s
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So where are all the tell-tale signs?
The fact that you'd actually ask that suggests "spectrum-disorder delusion" (yes, I just came up with that) bordering on creepiness.
Pass me the bong.
It's a good idea for some people to get high.
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Life seems to find its way to wherever it's suitable. So where are all the tell-tale signs?
Such as? We can only look at exoplanets indirectly to determine their composition, so not lots to go on and we haven't really looked at that many stars. Were you expecting megastructures? If you were, I have bad news because not only are they are impractical, they would eventually falter and get absorbed by their host star in mere millions of years. It would mean everyone would need to build some pointless monstrosity around the same time in order for us to spot even one of them.
Planets are the ideal me
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Space is big. Really big.
roughly half of all stars are in binary systems.. (Score:4, Funny)
So the other half of all stars are the other star in the binary systems? =)
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Have they found (Score:2)
tatooine yet?
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Have they found tatooine yet?
How could they? It's in a galaxy far far away. We have trouble identifying planets around stars in our own galaxy. Other galaxies are out of the question.
We need a Lunar base for no other reason than a convenient place to build some really big telescopes in no atmosphere where there's enough gravity to keep humans relatively comfortable while also being low enough to exploit for construction purposes. Two week long nights will also be helpful for observations. Lunar base telescopes don't have all of th
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I'll take that as a 'no'
Wait, what? Tess? (Score:2)
This is really good news (Score:2)
The most common stars, red dwarfs, have been a bit problematic for those hoping to find other Earths out there, because of their tendency to flare. Binary red dwarfs are theorized to be a lot calmer because they would tidally lock to each other, and this would tame their magnetic fields.
Earth-sized, no goldilocks (Score:2)
The real questions are what are their orbits like... and if one of the binary (or triple-star) systems have such planets, and one or more of the stars is, say, a flaring red dwarf, that really suggests it would be bad for humans, never mind the likelihood of "life as we know it, Jim" biospheres.
Then why the Fermi paradox? (Score:2)
Almost makes it sound like life
Re:Then why the Fermi paradox? (Score:5, Insightful)
First, Space is big. Really big. If you're not looking in exactly the right place at the right time, you're not going to see what you're looking for. And the windows for detection are incredibly small. After all, we're only detectable to something orbiting about a dozen stars now, and only if they happen to be looking in exactly the right direction at the right time. And we're getting quieter every year.
Second, it's extremely unlikely that a multi-star-system civilization is going to use light or radio to communicate. It's way, way too slow to actually keep your civilization coherent - if it takes years for a message to travel between two stars, you have two single-star civilizations, not one 2-star civilization. Which means if such a civilization exists, they're not communicating in a way we can detect.
Third, we have no idea just how rare the right conditions for intelligent life are. Our relatively large moon required an extremely unlikely collision, and it stabilizes Earth's rotation so that we have sufficient stability in our weather to develop intelligent life. Our solar system formed from a nebula with much more phosphorus than normal, and life on Earth has a lot of structures and processes that require the unique properties of phosphorus. Jupiter is in an unusual orbit, and vacuums up a ton of debris that would devastate Earth. Add those factors up (and the ones we don't realize are unique yet), and even with billions of candidates there may only be a handful of similar planets in the milky way.
Fourth, it takes a really, really long time for sufficient heavy elements to form to make intelligent life. It took one generation of stars before anything heavier than lithium existed at all, much less in sufficient quantities for intelligent life. We could very well be among the first just on this limitation alone.
Fifth, why would they make efforts contact us? It's pretty narcissistic to think we're so special that they'd want to chat.
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Our relatively large moon required an extremely unlikely collision, and it stabilizes Earth's rotation /. myth.
That is a kind of
Look at Mars, Venus, or even tidal locked Mercury: they rotate pretty well without a moon.
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The other planets you cite wobble on their axis more than Earth does. Those wobbles would create much more variable climates for the life on them. Climate stability is rather important for evolving intelligent life.
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There is no evidence that climate stability - or the lack of that - has anything to do with evolution of life.
Earth was once covered completely in ice. Volcanoes brought back enough CO2 to smelt it. Live continued in the deep seas.
Climate stability is rather important for evolving intelligent life. We most likely will never know.
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There is no evidence that climate stability - or the lack of that - has anything to do with evolution of life.
As long as you ignore the mass extinctions caused when the climate changes.
Earth was once covered completely in ice. Volcanoes brought back enough CO2 to smelt it.
Slowly.
The wobbles I'm talking about happen much faster. If you're a plant evolved for Florida's climate, finding yourself in Canada 2 years from now is going to kill you.
Live continued in the deep seas.
"Life" and "intelligent life" are different things. Some form of life can exist in extreme environments. That life will not be intelligent, because the constant radical changes will kill off a ton of species before they have the chance to evolve into intelligent
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As long as you ignore the mass extinctions caused when the climate changes.
That were mostly meteor/comets impacts.
"Life" and "intelligent life" are different things.
Dos not really matter if it is intelligent or not. There is a funny SF story where intelligent dinosaurs survived on the moon, but got into deep sleep. When they woke up they wanted to conquer the earth. (A no name SF author, cannot find the story now) But it is funny.
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Second, humans emit all kinds of signals and every physical thing emits some form of radiation. If the UK couldn't stop pirate radio it's unlikely to think a single alien civilization could stomp it all out
Third, (I'm agreeing with you
Are they planets though? (Score:2)
Earth-sized planets may be much more common than previously realized
We used to think Pluto was a planet, but not anymore when how many bodies of that size were discovered.
Perhaps Earth as well should be considered no longer a planet -- and downgrade Earth to new name: Microplanet. The true planets are such bodies as Jupiter, Neptune -- much larger.