Posts Tagged ‘Kepler’
Kepler Spots a Planet Orbiting Two Suns, Just Like Star Wars’ Tatooine
Using data from the Kepler space observatory, scientists at the Harvard-Smithsonian Center for Astrophysics and SETI have discovered for the first time a planet orbiting a binary star system, passing in front of both its parent stars along its orbit.
The planet, Kepler-16b, resembles Saturn in its mass and gaseous makeup. That mostly rules out the possibility of any living beings being present to enjoy the double sunset view, although chances are good Kepler-16b has an icy, non-gaseous satellite or two, as Saturn does.
The two stars in the system are 20% and 69% as massive as our sun, respectively. The planet orbits at a distance analogous to Venus's orbit in our solar system, which typically would place it within the "habitable zone" of planets that could support life. But since the combined mass of the two stars is still less than our sun, Kepler-16b's Venus-like orbit is most likely a cold one.
An animation of Kepler-16b's orbit:
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Binary star systems, first cataloged at length by English astronomer William Herschel in the early 19th century, are key to our understanding of distant stars, since it's easy to derive each star's mass by studying their linked orbit (the two stars in a binary system both orbit around their shared center of mass). But whether or not such systems, which by some estimates account for about half of the stars in the known universe, could form and support orbiting planets has been a contentious topic--making today's finding significant not just for Star Wars fans.
"It's been pretty much a split vote amongst the theorists," said Alan Boss, a theoretical astrophysicist at the Carnegie Institution for Science, and a co-author of the Kepler 16-b paper. "Some say 'Yeah, we think it's possible to make a Saturn-mass object [in a binary star system].' Other papers say 'Well, no, we don't think it's going to work at all, because those changing gravitational forces from that central binary are going to screw up the process of trying to get little bodies to run into each other and grow bigger and bigger.'"
"One of the exciting things about this is: Kepler, as usual, has answered the question for us," said Boss.
The mission is to find and analyze potential Earth-like exoplanets throughout the universe. Today's discovery now significantly expands the working set of stars that could potentially harbor orbiting planets. That means more work for Kepler as it continues what has so far been an extremely successful mission.
The paper, authored primarily by Laurence Doyle of the SETI institute, appears in the journal Science today.
Blackest Planet Ever Found, Absorbs Nearly 100% of Light That Reaches It
But TrES-2b is not completely black. It emits an extremely faint red glow, like that of a hot ember. And it turns out that heat is the main culprit behind this darkest of dark planets. TrES-2b orbits its star at a distance of just 3 million miles (by comparison, we’re about 93 million miles from our sun), which leads to surface temperatures on TrES-2b of more than 1,800 degrees.
That’s too hot for the formation of ammonia clouds that would reflect some of that incoming radiation as they do on Jupiter. Rather, TrES-2b’s atmosphere is made up of things like vaporized sodium, potassium, and titanium oxide--things that actually compound the problem by absorbing heat. But even these don’t fully explain the planet’s extreme blackness, which is still puzzling astronomers. There's some kind of strange chemistry going on out there that even Kepler can't see.
SETI Turns Radio Telescopes Toward Kepler Candidate Planets, Listening for Signs of Life
Listening to places where conditions are right for life
The SETI Institute is looking at Earth-like (rocky) planets with a focus on those with temperatures between 0 and 100 °C (32° and 212 °F), where liquid water can exist. As far as our Earth-biased science can tell us, that’s a crucial ingredient for life.
SETI has been listening to parts of the sky for decades, but pointing directly at Kepler findings stands among the project’s best-informed attempts yet. The Arecibo telescope in Puerto Rico looks at stars like the sun, hoping they might have planets around them.
“But we’ve never had a list of planets like this before,” said physicist Dan Werthimer, director of the SETI project at Arecibo, in an .
In February, Kepler scientists announced they had found orbiting sun-like stars in the Milky Way, including 68 approximately Earth-size and 288 super-Earth-size. Scientists have been verifying and refining the measurements in the months since.
The Robert C. Byrd Green Bank Telescope will gather 24 hours of data on each of 86 planets identified this spring by the Kepler space telescope science team as potential Earth-like planets in “Goldilocks” orbits, where conditions are neither too hot nor too cold for liquid water.
SETI has its own telescopes, too, but apparently they’ve gone dark for a lack of funding, according to the AFP — SETI announced last month it was shutting down its 42-dish Allen Telescope Array because of a budget shortfall, AFP reports. While the 4-year-old, $50 million project is on hiatus, the Green Bank telescope will assume its responsibilities.
While Arecibo will also keep listening, Green Bank can hear a lot more — it scans 300 times the range of frequencies that Arecibo can, so it can collect as much data in one day as Arecibo could in one year.
The Kepler listening project will take about a year, AFP reports. SETI@home users will help crunch the data; the program uses small bits of unused processing power from idle Internet-connected computers to run calculations. You can find out more, and sign up to help, by .
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SETI Turns Radio Telescopes Toward Kepler Candidate Planets, Listening for Signs of Life
Listening to places where conditions are right for life
The SETI Institute is looking at Earth-like (rocky) planets with a focus on those with temperatures between 0 and 100 °C (32° and 212 °F), where liquid water can exist. As far as our Earth-biased science can tell us, that’s a crucial ingredient for life.
SETI has been listening to parts of the sky for decades, but pointing directly at Kepler findings stands among the project’s best-informed attempts yet. The Arecibo telescope in Puerto Rico looks at stars like the sun, hoping they might have planets around them.
“But we’ve never had a list of planets like this before,” said physicist Dan Werthimer, director of the SETI project at Arecibo, in an .
In February, Kepler scientists announced they had found orbiting sun-like stars in the Milky Way, including 68 approximately Earth-size and 288 super-Earth-size. Scientists have been verifying and refining the measurements in the months since.
The Robert C. Byrd Green Bank Telescope will gather 24 hours of data on each of 86 planets identified this spring by the Kepler space telescope science team as potential Earth-like planets in “Goldilocks” orbits, where conditions are neither too hot nor too cold for liquid water.
SETI has its own telescopes, too, but apparently they’ve gone dark for a lack of funding, according to the AFP — SETI announced last month it was shutting down its 42-dish Allen Telescope Array because of a budget shortfall, AFP reports. While the 4-year-old, $50 million project is on hiatus, the Green Bank telescope will assume its responsibilities.
While Arecibo will also keep listening, Green Bank can hear a lot more — it scans 300 times the range of frequencies that Arecibo can, so it can collect as much data in one day as Arecibo could in one year.
The Kepler listening project will take about a year, AFP reports. SETI@home users will help crunch the data; the program uses small bits of unused processing power from idle Internet-connected computers to run calculations. You can find out more, and sign up to help, by .
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SETI Turns Radio Telescopes Toward Kepler Candidate Planets, Listening for Signs of Life
Listening to places where conditions are right for life
The SETI Institute is looking at Earth-like (rocky) planets with a focus on those with temperatures between 0 and 100 °C (32° and 212 °F), where liquid water can exist. As far as our Earth-biased science can tell us, that’s a crucial ingredient for life.
SETI has been listening to parts of the sky for decades, but pointing directly at Kepler findings stands among the project’s best-informed attempts yet. The Arecibo telescope in Puerto Rico looks at stars like the sun, hoping they might have planets around them.
“But we’ve never had a list of planets like this before,” said physicist Dan Werthimer, director of the SETI project at Arecibo, in an .
In February, Kepler scientists announced they had found orbiting sun-like stars in the Milky Way, including 68 approximately Earth-size and 288 super-Earth-size. Scientists have been verifying and refining the measurements in the months since.
The Robert C. Byrd Green Bank Telescope will gather 24 hours of data on each of 86 planets identified this spring by the Kepler space telescope science team as potential Earth-like planets in “Goldilocks” orbits, where conditions are neither too hot nor too cold for liquid water.
SETI has its own telescopes, too, but apparently they’ve gone dark for a lack of funding, according to the AFP — SETI announced last month it was shutting down its 42-dish Allen Telescope Array because of a budget shortfall, AFP reports. While the 4-year-old, $50 million project is on hiatus, the Green Bank telescope will assume its responsibilities.
While Arecibo will also keep listening, Green Bank can hear a lot more — it scans 300 times the range of frequencies that Arecibo can, so it can collect as much data in one day as Arecibo could in one year.
The Kepler listening project will take about a year, AFP reports. SETI@home users will help crunch the data; the program uses small bits of unused processing power from idle Internet-connected computers to run calculations. You can find out more, and sign up to help, by .
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Kepler’s Ongoing Exoplanet Findings Show Bizarre Solar Systems And Peculiar Planets
Last month, Kepler scientists announced a trove of , at least 15 of which are definitely planets. Scientists are in the process of determining whether the rest of the objects are planets, too, or if they’re binary stars or something else. So far, the Kepler “Objects of Interest” are pretty interesting.
Take KOI 191, which involves four planets in unstable orbits. Jack Lissauer, a co-investigator for the Kepler mission at NASA’s Ames Research Center, tells the planets are probably in resonances that keep them in their places — orbits that cross each other but don’t come very close.
This is the case for Pluto and Neptune, which are in a 3:2 resonance. For every three times Neptune orbits the sun, Pluto orbits twice, and the cycle repeats every 500 years. Their dance keeps their orbits stable, which Lissauer says might be the case for KOI 191.
Lissauer and other Kepler scientists submitted a research paper last week saying they had found planets , which would be possible if they inhabited a Trojan configuration — named for a Jovian example involving some asteroids. In such a system, involving a planet and a star, there are Lagrange points 60 degrees ahead and 60 degrees behind the planet in which a smaller body can safely orbit. But now, Lissauer says he’s skeptical of this interpretation of KOI 730, and that a resonance system could explain the shared orbits. If that’s the case, the four planets in KOI 730 would have orbits in the resonances 8:6:4:3. In other words, there are two pairs of planets, and each time the first member of the pair makes three orbits, another planet completes four, IB Times explains.
Finally, there’s KOI 500, which has five planets with orbital periods ranging from under one day to 9.5 days. If confirmed, the planets will be in some of the smallest orbits ever found, with the innermost planet staying toasty despite the star’s relatively cool temperature.
Just a few months ago, exoplanets — and especially exoplanet systems — were a rare and compelling find. Now that we know they’re a dime a dozen, their individual characteristics are becoming the most interesting aspect of exoplanet research. Stay tuned as more and more Kepler data reaches the scientific literature.
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New-Found Cornucopia of Exoplanets More Than Doubles the Current Cosmic Census
The Kepler telescope team announces a trove
Today’s results more than double the exoplanet-candidate population, bringing the number of planet candidates identified by Kepler to 1,235. NASA needs to conduct follow-up observations to be sure their candidate planets are actually planets. So far, they are certain about 15 of them.
"The fact that we've found so many planet candidates in such a tiny fraction of the sky suggests there are countless planets orbiting sun-like stars in our galaxy," said William Borucki of NASA's Ames Research Center in Moffett Field, Calif., the father of Kepler and its principal investigator.
Small, Earth-like planets are apparently more common than gas giants like Jupiter, according to today's announcement. Sixty-eight of the new planet candidates are approximately
Earth-size, and another 288 are super-Earth-size; 662 are Neptune-size; 165 are the size of Jupiter and 19 are larger than Jupiter, NASA said.
NASA said today that 54 planet candidates are in their stars’ Goldilocks zones — not too hot, not too cold, not too far, not too old — which means they might have liquid water, and therefore a key ingredient for life. Of those 54, five are near the size of Earth. Pretty stunning news when you think about it: In one tiny slice of the sky, scientists have found five other planets that may very well resemble our own.
Since launching in 2009, Kepler has been staring at a bunch of stars in the constellations Cygnus and Lyra, looking for small blips in their brightness that would indicate a planet circling around them. Kepler astronomers released data on about 156,000 stars last summer, allowing competing scientists to check them out. The team potentially promising star systems for further study, and those are among the data announced today.
Kepler team members have said they wanted to check and double-check the promising stars so they don’t have any false positives. Other physicists say they’ve been pretty good at this so far — the telescope has had an accuracy rate of at least 80 percent, according to a review by . Taking a high-resolution picture of a possible exoplanet candidate can help with follow-up observations, they say. Scientists will want to check out NASA's new findings, and physicists would like some statistical models to help them sift through all that data.
Even before today's announcement, new planet discoveries have been trickling out in the past few months, including the recent news of Kepler’s to date: Kepler 10b, just 1.4 times the size of Earth. That fiery world is much too close to its star to harbor water, and therefore unlikely to harbor life (at least the kind we understand).
In the new data, there are at least 170 exo-solar-systems harboring multiple planets, NASA said. Kepler-11, located 2,000 light years from Earth, includes six planets in a tight orbit around a yellow dwarf star. New research on Kepler-11 will be published in the Feb. 3 issue of Nature. Other findings are being published in Astrophysical Journal.