Tag Archives: Kepler

The clouds of hot Jupiter exoplanets

Exoplanet clouds

Cool image time! The image on the right, reduced to show here, provides an overall summary of what astronomers know about the atmospheres of many gas giant exoplanets that also orbit very close to their suns and are tidally locked. The view is of the planet hemisphere facing away from the star, which is also where most of the clouds are thought to be. These results come from Kepler data combined with computer modeling, and show what scientists thinks happens with different cloud compositions at different temperatures.

Link fixed!

100 Kepler exoplanet candidates confirmed

Worlds without end: Astronomers have confirmed another 100 of Kepler’s more than 3,000 candidate exoplanets.

One of the most interesting set of planets discovered in this study is a system of four potentially rocky planets, between 20 and 50 percent larger than Earth, orbiting a star less than half the size and with less light output than the Sun. Their orbital periods range from five-and-a-half to 24 days, and two of them may experience radiation levels from their star comparable to those on Earth.

Despite their tight orbits—closer than Mercury’s orbit around the sun—the possibility that life could arise on a planet around such a star cannot be ruled out, according to Crossfield.

Because the host star of this as well as many of these other confirmed exoplanets are red dwarf stars, the possibility of life is reduced because the star and its system is likely to have a less rich mix of elements compared to our yellow G-type Sun.

NASA uses computer model to find exoplanets

Garbage in, garbage out: Using statistical computer modeling only, NASA today announced that they are certain that almost a third of Kepler’s candidate exoplanets are really exoplanets.

Analysis was performed on the Kepler space telescope’s July 2015 planet candidate catalog, which identified 4,302 potential planets. For 1,284 of the candidates, the probability of being a planet is greater than 99 percent – the minimum required to earn the status of “planet.” An additional 1,327 candidates are more likely than not to be actual planets, but they do not meet the 99 percent threshold and will require additional study. The remaining 707 are more likely to be some other astrophysical phenomena. This analysis also validated 984 candidates previously verified by other techniques.

This is actually a stupid announcement. They haven’t learned a damn thing from this statistical analysis, but are merely saying that because Kepler found a lot of candidates, a lot of those candidates must be real planets. Worse, NASA is also implying here that confirming some of these candidate exoplanets by hard observations is now really unnecessary, since they can do it statistically.

This smacks of the corruption that has ruined much of climate research, allowing a computer model to replace actual observations. Big mistake. But I also suspect this announcement occurred for the same reasons: NASA wishes to justify its work and its funding, and thus decided to make a big deal about this very minor statistical analysis in order to puff up the discoveries of Kepler, even though there is no reason to do so.

I expect a lot of mainstream news organizations to write big puff pieces extolling this announcement in the coming days, which will once again prove that almost no one in journalism today has the slightest ability to apply their own independent analysis to the press releases they receive.

Kepler in trouble

Engineers report that the Kepler space telescope went into safe mode about two days ago.

During a scheduled contact on Thursday, April 7, mission operations engineers discovered that the Kepler spacecraft was in Emergency Mode (EM). EM is the lowest operational mode and is fuel intensive. Recovering from EM is the team’s priority at this time.

The mission has declared a spacecraft emergency, which provides priority access to ground-based communications at the agency’s Deep Space Network. Initial indications are that Kepler entered EM approximately 36 hours ago, before mission operations began the maneuver to orient the spacecraft to point toward the center of the Milky Way for the K2 mission’s microlensing observing campaign.

This brief report does not look good. If the spacecraft is in a “fuel intensive” mode, it means it is using extra fuel to survive. This suggests that if they don’t recover it soon it might run out of the fuel and be lost forever.

More than half Kepler planet candidates false positives

The uncertainty of science: In attempting to confirm the giant exoplanet candidates in the Kepler telescope database a team of scientists has found that more than half are not planets at all but false positives.

An international team1 led by Alexandre Santerne from Instituto de Astrofísica e Ciências do Espaço (IA), made a 5-year radial velocity campaign of Kepler’s giant exoplanet candidates, using the SOPHIE spectrograph (Observatory of Haute-Provence, France), and found that 52,3% were actually eclipsing binaries, while 2,3% were brown dwarfs. Santerne (IA & University of Porto), first author of this paper commented: “It was thought that the reliability of the Kepler exoplanets detection was very good – between 10 and 20% of them were not planets. Our extensive spectroscopic survey, of the largest exoplanets discovered by Kepler, shows that this percentage is much higher, even above 50%.

The news article above is unclear about the number of candidates total this study actually looked at and pinned down. It appears they began looking at the full database of almost 9,000 candidates, but then narrowed it to 125. Were 50% of the 9,000 false positives, or of the 125? The article is unclear.

At first glance, this study appears to tell us that there might be fewer giant Jupiter-sized exoplanets out there than previously thought. Then again, the data is uncertain enough that this conclusion could easily be wrong. The real take-away is that the science of exoplanets has only just begun, and that sweeping generalizations about the nature of solar systems in the galaxy are exceedingly unreliable. We simply don’t know enough yet.

No sign of alien civilization at distant star

The uncertainty of science: Two weeks of targeted observations by the Allen Telescope Array in California have detected no clear signal of an alien civilization at the star KIC 8462852 where Kepler observations have seen variations that could possibly be caused by giant alien structures.

Two different types of radio signals were sought: (1) Narrow-band signals, of order 1 Hz in width, such as would be generated as a “hailing signal” for societies wishing to announce their presence. This is the type of signal most frequently looked for by radio SETI experiments.  (2) Broad-band signals that might be due to beamed propulsion within this star system.  If astroengineering projects are really underway in the vicinity of KIC 8462852, one might reasonably expect the presence of spacecraft to service this activity.  If these craft are propelled by intense microwave beams, some of that energy might manifest itself as broad-band radio leakage. “This is the first time we’ve used the Allen Telescope Array to look for relatively wide-band signals, a type of emission that is generally not considered in SETI searches,” said SETI Institute scientist Gerry Harp.

Analysis of the Array data show no clear evidence for either type of signal between the frequencies of 1 and 10 GHz.  This rules out omnidirectional transmitters of approximately 100 times today’s total terrestrial energy usage in the case of the narrow-band signals, and ten million times that usage for broad band emissions.

The data shows no sign of alien civilization, but it also does not eliminate the possibility. More detailed observations are required to do that.

Astronomers confirm Kepler discovery of near twin of Earth

Worlds without end! In the release today of another set of Kepler data, astronomers have announced the discovery in that dataset of a new twin of Earth.

The newly discovered Kepler-452b is the smallest planet to date discovered orbiting in the habitable zone — the area around a star where liquid water could pool on the surface of an orbiting planet — of a G2-type star, like our sun. The confirmation of Kepler-452b brings the total number of confirmed planets to 1,030. …

Kepler-452b is 60 percent larger in diameter than Earth and is considered a super-Earth-size planet. While its mass and composition are not yet determined, previous research suggests that planets the size of Kepler-452b have a good chance of being rocky. While Kepler-452b is larger than Earth, its 385-day orbit is only 5 percent longer. The planet is 5 percent farther from its parent star Kepler-452 than Earth is from the Sun. Kepler-452 is 6 billion years old, 1.5 billion years older than our sun, has the same temperature, and is 20 percent brighter and has a diameter 10 percent larger.

While this exoplanet is certainly not identical to Earth, it is close enough that the possibility of alien life — really alien life — could very likely exist upon it.

The dataset also included 11 other Earth twin candidate exoplanets that still need to be confirmed.

More Earthlike exoplanets found

Worlds without end: Using Kepler astronomers have discovered a red dwarf star 150 light years away with three Earth-like exoplanets, one of which is in the habitable zone.

The three planets are 2.1, 1.7 and 1.5 times the size of Earth. The outermost planet, at 1.5 Earth radii, is the smallest of the bunch and orbits far enough from its host star that it receives levels of light from its star similar to those received by Earth from the sun, said UC Berkeley graduate student Erik Petigura, who discovered the planets Jan. 6 while conducting a computer analysis of the Kepler data NASA has made available to astronomers. He calculated that the three planets receive 10.5, 3.2, and 1.4 times the light intensity of Earth. “Most planets we have found to date are scorched. This system is the closest star with lukewarm transiting planets,” Petigura said. “There is a very real possibility that the outermost planet is rocky like Earth, which means this planet could have the right temperature to support liquid water oceans.”

These planets were found by Kepler in its present reconfigured mission, which once again illustrates the incredible effectiveness of an optical telescope in space. If only we were building some.

More Earthlike exoplanets confirmed

Worlds without end: Astronomers have confirmed from Kepler data the existence of 8 new exoplanets, all capable of having liquid water on their surface, with two more like Earth than any previous discovery.

These findings nearly double the number of known planets in the habitable zone, but researchers are especially excited about two of the new exoplanets: Their size, location, and star type means they could be rocky planets like Earth — which means they could have evolved life as we recognize it.

One of the planets, Kepler-438b, is only 12 percent bigger than Earth in diameter. That means it’s quite likely a rocky planet. Scientists have given it a 70 percent chance. Kepler-442b is a bit bigger at around 33 percent larger than Earth, but still has a 60 percent chance of being rocky.

But while 438b hits the sweet spot in size, 442b has it beat when it comes to distance from the sun. Both planets orbit a small red dwarf star, cooler than Earth’s Sun, but they also orbit more closely. 438b gets 40 percent more light than Earth, which means it has around a 70 percent chance of being able to hold liquid water. But with 66 percent as much light as our own planet, 442b has a 97 percent chance of being in the habitable zone.

Kepler reborn

Kepler detects its first exoplanet after its mission was reshaped because of the failure of two of its four gyros.

The newfound planet, HIP 116454b, has a diameter of 20,000 miles, two and a half times the size of Earth. HARPS-N showed that it weighs almost 12 times as much as Earth. This makes HIP 116454b a super-Earth, a class of planets that doesn’t exist in our solar system. The average density suggests that this planet is either a water world (composed of about three-fourths water and one-fourth rock) or a mini-Neptune with an extended, gaseous atmosphere.

This close-in planet circles its star once every 9.1 days at a distance of 8.4 million miles. Its host star is a type K orange dwarf slightly smaller and cooler than our sun. The system is 180 light-years from Earth in the constellation Pisces.

Even more cool, the detection took place during Kepler’s first test run in its new configuration. This bodes well for the space telescope’s ability to make future discoveries.

An exoplanet with an orbit like Mars

Using Kepler astronomers have discovered a Uranus-sized exoplanet with the longest known orbit, 704 days.

Kepler-421b orbits an orange, type K star that is cooler and dimmer than our Sun. It circles the star at a distance of about 110 million miles. As a result, this Uranus-sized planet is chilled to a temperature of -135° Fahrenheit.

As the name implies, Kepler-421b was discovered using data from NASA’s Kepler spacecraft. Kepler was uniquely suited to make this discovery. The spacecraft stared at the same patch of sky for 4 years, watching for stars that dim as planets cross in front of them. No other existing or planned mission shows such long-term, dedicated focus. Despite its patience, Kepler only detected two transits of Kepler-421b due to that world’s extremely long orbital period.

The planet’s orbit places it beyond the “snow line” – the dividing line between rocky and gas planets. Outside of the snow line, water condenses into ice grains that stick together to build gas giant planets.

Posted from Bright Angel Lodge on the rim of the Grand Canyon.

NASA has approved a new mission for the crippled Kepler space telescope, allowing observations to continue for another two years.

Like a phoenix: NASA has officially approved the new mission for the crippled Kepler space telescope, allowing observations to continue for another two years.

During the K2 mission, Kepler will stare at target fields in the plane of Earth’s orbit, known as the ecliptic, during observing campaigns that last about 75 days each. In this orientation, solar radiation pressure can help balance the spacecraft, making the most of Kepler’s compromised pointing ability, team members said.

Hopefully the application of clever engineering will allow scientists to get data good enough to spot some more exoplanets.

The existence of a Kepler-found earth-sized planet in the habitable zone has been confirmed.

Worlds without end: The existence of a Kepler-found earth-sized planet in the habitable zone has been confirmed.

The newfound planet, called Kepler-186f, was first spotted by NASA’s Kepler space telescope and circles a dim red dwarf star about 490 light-years from Earth. While the host star is dimmer than Earth’s sun and the planet is slightly bigger than Earth, the positioning of the alien world coupled with its size suggests that Kepler-186f could have water on its surface, scientists say.

In this new work, the Keck and Gemini ground-based telescopes confirmed Kepler’s discovery.

Using archived Kepler data combined with statistical modeling, scientists have proposed the discovery of another 715 exoplanets.

Using archived Kepler data combined with statistical modeling, scientists have proposed the discovery of another 715 exoplanets.

This announcement is neat, but despite the many news stories about it today, it should be taken with a grain of salt. What the scientists have really done is pinpoint 715 stars where further research is likely to produce good exoplanet results. It is not guaranteed, however, that a scientist looking at these stars will actually see an exoplanet.

The ingenious plan engineers have devised to do good science with the crippled Kepler space telescope.

The ingenious plan engineers have devised to do good science with the crippled Kepler space telescope.

They are going to use the spacecraft’s solar panels as a pseudo third reaction wheel. This will allow it to point with acceptable accuracy for short periods.

The number of candidate exoplanets found by Kepler has now risen to 3,500.

Worlds without end: The number of candidate exoplanets found by Kepler has now risen to 3,500.

According to this new analysis, researchers estimate about 70% of stars are host to at least one planet, making planets a common cosmic occurrence. There are now 1,750 candidates that are super-Earth-size or smaller, and 1,788 are Neptune-size or larger. Only 167 of the 3,538 candidates are confirmed to be planets, but Kepler has a good track record: the vast majority of these are probably real.

Two dozen of these candidates are in the habitable zone, ten of which are thought to be close to Earth-sized.

Scientists now estimate that one in five sunlike stars have Earthlike planets in the habitable zone.

Scientists now estimate that one in five sunlike stars have Earthlike planets in the habitable zone.

This conclusion is entirely statistically based, and should be treated with some skepticism. Still, it seems reasonable, and I think it is likely to be a close approximation of the truth, when we finally begin to gather some real data.

China complains about the ban of its scientists at a NASA Kepler conference.

China complains about the ban of its scientists at a NASA Kepler conference.

The meeting is a key event for scientists searching for planets beyond the solar system. NASA has rejected applications from Chinese nationals, citing a new security law. In Beijing, foreign ministry spokeswoman Hua Chunying called the move “discriminatory”. The conference is for US and international teams who work on Nasa’s Kepler space telescope program. It will be held at Nasa’s Ames research centre in California next month.

And I say, tough. China does not distinguish between civilian and military research, and in fact has often used its scientists to do espionage, stealing both military and industry secrets in the process.

Posted in Virginia as we pass through Harrisonburg. Note again that Diane, not I, is doing the driving.

Astronomers submit a slew of proposals for using the partly crippled Kepler space telescope.

Astronomers submit a slew of proposals for using the partly crippled Kepler space telescope.

Ideas range from a survey of potentially hazardous near-Earth objects to a study of Jupiter-sized exoplanets in large orbits. Kepler scientists will sort through the proposals and decide by 1 November which ones, if any, to recommend to NASA headquarters for further review.

Sadly, none of these ideas excites me very much. The tragedy here is that we have this really good optical telescope above the atmosphere, and we can’t point it accurately enough to use it.

NASA will reactivate the Wide-field Infrared Survey Explorer (WISE) next month to use it to look for more near Earth asteroids.

NASA will reactivate the Wide-field Infrared Survey Explorer (WISE) next month to use it to look for more near Earth asteroids.

This decision raises two thoughts.

  • Why did they shut it down in the first place if it was still viable and could still do important research? If the cost wasn’t worth the benefit then, how has this equation changed now? And if the cost was worth the benefit, it then was foolish to shut it down in the first place. Though it costs money to operate these things, it is always cheaper to keep something running than to build something new. The press announcement above doesn’t really address these issues, and I wish it did.
  • I wonder if this decision is somehow related to the end of the Kepler mission. With Kepler out of service, maybe NASA decided to shift the funds to run that telescope over to WISE. They do not say, but the timing is interesting. This decision could be a hint that Kepler doesn’t really have another mission it can fulfill, and thus the money to run it has already been put elsewhere.

The engineering tests to try to save Kepler have found that the mission is essentially over.

The engineering tests to try to save Kepler have found that the mission is essentially over.

A headline at this New York Times article, “NASA’s Kepler Mended, but May Never Fully Recover” is wrong, as the telescope has not been “mended.” They have found they might be able to do some limited science, at the most. NASA is going to review this possibility, weighing the cost versus the benefit, and decide in the fall.

Engineers will attempt one more try this month to revive one of Kepler’s reaction wheels so that the telescope can resume observations.

Engineers will attempt one more try this month to revive one of Kepler’s reaction wheels so that the telescope can resume observations.

They admit that the odds are not good that the attempt will work, but they are going to give it chance anyway.

The count of candidate exoplanets found by Kepler has now risen another 503 to 3,216, of which only 132 have been confirmed.

The count of candidate exoplanets found by Kepler has now risen another 503 to 3,216, of which only 132 have been confirmed.

These new exoplanets were found before the telescope failed but the data for them is only now being released.

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