Tag Archives: exoplanets

SuperEarth orbiting Barnard’s Star?

The uncertainty of science: Astronomers have discovered a candidate exoplanet orbiting Barnard’s Star, the closest single star to our solar system and the second closest stellar system after Alpha Centauri.

The planet candidate, named Barnard’s star b (or GJ 699 b), is a super-Earth with a minimum of 3.2 Earth masses. It orbits its cool red parent star every 233 days near the snow-line, a distance where water would be frozen. In the absence of an atmosphere, its temperature is likely to be about -150 ºC, which makes it unlikely that the planet can sustain liquid water on its surface. However, its characteristics make it an excellent target for direct imaging using the next generation of instruments such as NASA’s Wide Field InfraRed Survey Telescope (WFIRST, [3]), and maybe with observations from the ESA mission Gaia [4].

The reason I put a question mark in the headline is that this is not the first time a candidate exoplanet has been proposed to orbit Barnard’s Star. In the 1960s astronomer Peter van de Kemp claimed the star had at least one gas giant orbiting it every 24 years. It was later found that the periodic motion variations he measured were due to “to an artifact of maintenance and upgrade work” at the telescope he was using.

The result above has not been confirmed by other means, so they must list this superEarth as a candidate exoplanet. More observations are necessary to confirm it.

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NASA officially retires Kepler

NASA today officially retired Kepler after nine years of operations.

After nine years in deep space collecting data that indicate our sky to be filled with billions of hidden planets – more planets even than stars – NASA’s Kepler space telescope has run out of fuel needed for further science operations. NASA has decided to retire the spacecraft within its current, safe orbit, away from Earth. Kepler leaves a legacy of more than 2,600 planet discoveries from outside our solar system, many of which could be promising places for life.

Exoplanet hunting however does not end here. Unlike Hubble, astronomers and NASA planned ahead for Kepler’s demise, and this year launched TESS to continue its work, in an even more sophisticated manner.

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Number of candidate exo-Earths reduced by Gaia data

Worlds without end: The number of candidate exo-Earths identified by Kepler has now been reduced based on data from Europe’s Gaia telescope.

To date, NASA’s prolific Kepler space telescope has discovered about 30 roughly Earth-size exoplanets in their host stars’ “habitable zone” — the range of orbital distances at which liquid water can likely exist on a world’s surface.

Or so researchers had thought. New observations by the European Space Agency’s (ESA) Gaia spacecraft suggest that the actual number is probably significantly smaller — perhaps between two and 12, NASA officials said today.

Gaia launched in December of 2013 to create an ultraprecise 3D map of the Milky Way. So far, this map includes position information for about 1.7 billion stars and distance data for about 1.3 billion stars, according to NASA officials. Gaia’s observations suggest that some of the Kepler host stars are brighter and bigger than previously believed, the officials added. Planets orbiting such stars are therefore likely larger and hotter than previously thought.

Being hotter and larger, the habitable zone for these stars shifts outward, placing the exoEarth’s outside the habitable zone.

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Giant planets around young star defy model predictions

The uncertainty of science: The recent discovery of four Saturn/Jupiter-sized planets orbiting a star only about two million years old throws a wrench into all existing solar system formation theories.

The star, CI Tau, is located about 500 light years away in a highly-productive stellar ‘nursery’ region of the galaxy. Its four planets differ greatly in their orbits: the closest (the hot Jupiter) is within the equivalent of the orbit of Mercury, while the farthest orbits at a distance more than three times greater than that of Neptune. The two outer planets are about the mass of Saturn, while the two inner planets are respectively around one and 10 times the mass of Jupiter.

The discovery raises many questions for astronomers. Around 1% of stars host hot Jupiters, but most of the known hot Jupiters are hundreds of times older than CI Tau. “It is currently impossible to say whether the extreme planetary architecture seen in CI Tau is common in hot Jupiter systems because the way that these sibling planets were detected – through their effect on the protoplanetary disc – would not work in older systems which no longer have a protoplanetary disc,” said Professor Cathie Clarke from Cambridge’s Institute of Astronomy, the study’s first author.

According to the researchers, it is also unclear whether the sibling planets played a role in driving the innermost planet into its ultra-close orbit, and whether this is a mechanism that works in making hot Jupiters in general. And a further mystery is how the outer two planets formed at all.

“Planet formation models tend to focus on being able to make the types of planets that have been observed already, so new discoveries don’t necessarily fit the models,” said Clarke. “Saturn mass planets are supposed to form by first accumulating a solid core and then pulling in a layer of gas on top, but these processes are supposed to be very slow at large distances from the star. Most models will struggle to make planets of this mass at this distance.” [emphasis mine]

In other words, the present models are absurdly premature. We simply don’t know enough to formulate any theory that can be taken seriously.

This is not to say that models shouldn’t be formulated, only to emphasize that no one should consider them predictive of any part of reality. They give astronomers some guidance on what to look for, but if they take them too seriously they might not look in the right places.

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The first exomoon found?

Worlds without end: Scientists using data from the Hubble Space Telescope and Kepler have detected evidence that suggests the discovery of the first moon outside our solar system.

The data indicate an exomoon the size of Neptune, in a stellar system 8000 light-years from Earth. The new results are presented in the journal Science Advances.

…In 2017 NASA’s Kepler Space Telescope detected hints of an exomoon orbiting the planet Kepler-1625b. Now, two scientists from Columbia University in New York (USA) have used the incomparable capabilities of the NASA/ESA Hubble Space Telescope to study the star Kepler-1625, 8000 light-years away, and its planet in more detail. The new observations made with Hubble show compelling evidence for a large exomoon orbiting the only known planet of Kepler-1625. If confirmed, this would be the first discovery of a moon outside our Solar System.

The candidate moon, with the designation Kepler-1625b-i, is unusual because of its large size; it is comparable in diameter to the planet Neptune. Such gargantuan moons are unknown in our own Solar System. “This may yield new insights into the development of planetary systems and may cause astronomers to revisit theories of how moons form,” Alex Teachey, a graduate student who led the study, explained excitedly.

Like its moon, Kepler-1625b is also bigger than its counterparts in the Solar System. The exoplanet is a gas giant, several times more massive than Jupiter. It orbits its parent star at a distance similar to the distance between the Sun and Earth, which puts it — and its candidate moon — at the inner edge of the habitable zone of the star system.

The alien nature of this solar system should not surprise us. If anything, it is only a hint at the wild and exotic solar systems we have yet to discover.

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Vulcan found?

Scientists have found a super-earth orbiting 40 Eridani-A, a star located sixteen light years away and proposed by Gene Roddenberry in 1991 as the home star for his race of logical Vulcans.

It turns out the letter authors’ prediction was right — a world really does orbit the primary star of the three-star 40 Eridani system. (Whether it’s home to a logic-based alien society, though, is anyone’s guess!)

The world is a super-Earth, the most common type of planet in the galaxy (though a type that’s missing from our solar system). At twice Earth’s radius and eight to nine times its mass, 40 Eridani b sits on the line that divides rocky super-Earths from gaseous ones. The planet orbits its star every 42 days, putting just inside the system’s habitable zone — in other words, where it’s nice and hot. At 16 light-years away, it’s the closest super-Earth known and therefore a good potential target for followup observations.

The discovery was made by a survey taking place using a relatively small telescope right here in the Tucson area, on top of Mount Lemmon. Most cool!

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TESS releases its first batch of exoplanet candidates

The science team for the U.S.’s exoplanet space telescope TESS this week released its first batch of exoplanet candidates.

TESS scientists released the list so that other astronomers could make an initial determination as to whether these candidates are planets. There are 73 objects in this first batch, including some planets previously known from ground-based searches, says George Ricker, the mission’s principal investigator at the Massachusetts Institute of Technology in Cambridge. Perhaps 5 to 20% of the objects on the list will turn out to be false alarms, he says. Others, if confirmed, will join the ranks of newly discovered exoplanets.

Researchers expect TESS to find as many as 10,000 large planets. But its main goal is to discover and measure the masses of at least 50 small worlds no more than four times the size of Earth.

Meanwhile, Kepler has resumed operations despite being almost out of fuel. The science team there is attempting to squeeze every last ounce of data it can before the spacecraft’s fuel runs out.

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A gas giant exoplanet so hot it resembles a star

Link here. Key quote:

This sweltering exoplanet, located about 620 light-years away from Earth in the constellation Cygnus, is what astronomers call an “ultrahot Jupiter.” KELT-9b is a giant gas world like Jupiter, the largest planet in our solar system. But it’s way bigger — it has three times the mass and twice the diameter of Jupiter — and it orbits extremely close to its hot parent star, KELT-9.

“Ultrahot Jupiter” is an unofficial term for a hot Jupiter exoplanet with temperatures exceeding 3,100 degrees Fahrenheit (1,700 degrees Celsius). They “are so hot that they have some resemblance to being stars even though they’re planets,” Kevin Heng, an astrophysicist at the University of Bern in Switzerland who participated in the study, told Space.com. KELT-9b can reach temperatures of up to 7,800 degrees F (4,300 degrees C).

This record-breaking heat enabled astronomers to detect iron and titanium in KELT-9b’s atmosphere. While researchers have long suspected that these elements are present on some exoplanets — iron is one of the most abundant elements in the universe — it’s difficult to detect them in cooler environments because the atoms are mostly “trapped in other molecules,” Heng said. However, KELT-9b is so hot that the clouds don’t condense in its atmosphere, allowing individual atoms of iron and other metals to fly solo.

Titanium has been found previously in the atmosphere’s of other exoplanets, but only as part of a molecule.

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Tess captures comet, variable stars, asteroids, and Martian light

During its testing period prior to beginning science operations this month, the exoplanet space telescope TESS spotted in one series of images a comet, a host of variable stars, some asteroids, and even the faint hint of some reflected light from Mars.

Over the course of these tests, TESS took images of C/2018 N1, a comet discovered by NASA’s Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) satellite on June 29. The comet, located about 29 million miles (48 million kilometers) from Earth in the southern constellation Piscis Austrinus, is seen to move across the frame from right to left as it orbits the Sun. The comet’s tail, which consists of gases carried away from the comet by an outflow from the Sun called the solar wind, extends to the top of the frame and gradually pivots as the comet glides across the field of view.

In addition to the comet, the images reveal a treasure trove of other astronomical activity. The stars appear to shift between white and black as a result of image processing. The shift also highlights variable stars — which change brightness either as a result of pulsation, rapid rotation, or by eclipsing binary neighbors. Asteroids in our solar system appear as small white dots moving across the field of view. Towards the end of the video, one can see a faint broad arc of light moving across the middle section of the frame from left to right. This is stray light from Mars, which is located outside the frame. The images were taken when Mars was at its brightest near opposition, or its closest distance, to Earth.

The video that was compiled from these images is embedded below the fold.
» Read more

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Kepler on verge of death

The Kepler space telescope is now almost out of fuel, and scientists have ceased science observations to devote the telescope’s last days downloading its last 51 days of data.

The telescope lasted far longer than planned, and discovered thousands of exoplanets. Its archives will be producing new discoveries for decades. And a new exoplanet space telescope, TESS, is already in orbit to take over.

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More Earthlike exoplanets!

Astronomers using data from Kepler have discovered two stars, both with multiple orbiting Earth-sized planets. One has three planets all almost exactly the mass of Earth.

The first exoplanetary system is located in the star K2-239, characterized by these researchers as a red dwarf type M3V from observations made with the Gran Telescopio Canarias (GTC), at the Roque de los Muchachos Observatory (Garafía, La Palma). It is located in the constellation of the Sextant at 50 parsecs from the Sun (at about 160 light years). It has a compact system of at least three rocky planets of similar size to the Earth (1.1, 1.0 and 1.1 Earth radii) that orbit the star every 5.2, 7.8 and 10.1 days, respectively.

The other red dwarf star called K2-240 has two super-Earth-like planets about twice the size of our planet. Although the atmospheric temperature of red dwarf stars, around which these planets revolve, is 3,450 and 3,800 K respectively, almost half the temperature of our Sun, these researchers estimate that all planets discovered will have temperatures superficial tens of degrees higher than those of the planet Earth due to the strong radiation they receive in these close orbits to their stars.

Knowing more about the surface environments of these very Earthlike exoplanets, as hostile as they might be to life, would teach us a great deal about our own planet and its birth and evolution.

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Astronomers identify giant exoplanets that might harbor habitable moons

Worlds without end: In reviewing the known exoplanets astronomers have identified more than a hundred giant exoplanets located in the habitable zone that might harbor habitable moons.

The researchers identified 121 giant planets that have orbits within the habitable zones of their stars. At more than three times the radii of the Earth, these gaseous planets are less common than terrestrial planets, but each is expected to host several large moons.

Scientists have speculated that exomoons might provide a favorable environment for life, perhaps even better than Earth. That’s because they receive energy not only from their star, but also from radiation reflected from their planet. Until now, no exomoons have been confirmed.

Using this new database scientists will optimize future instruments on both the ground and in space to look for and study the moons circling these exoplanets.

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TESS completes lunar flyby, takes first test image

The Transiting Exoplanet Survey Satellite (TESS) yesterday successfully completed its slingshot flyby of the Moon to place it in its final operational orbit.

The spacecraft also used one of its four cameras to successfully take a 2-second test exposure, proving that the camera and pointing system both work. The first science image is expected in June.

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Hubble detects helium in exoplanet atmosphere

Using the Hubble Space Telescope astronomers have for the first time detected helium in the atmosphere of an exoplanet.

The team made the detection by analysing the infrared spectrum of the atmosphere of WASP-107b [1]. Previous detections of extended exoplanet atmospheres have been made by studying the spectrum at ultraviolet and optical wavelengths; this detection therefore demonstrates that exoplanet atmospheres can also be studied at longer wavelengths.

…WASP-107b is one of the lowest density planets known: While the planet is about the same size as Jupiter, it has only 12% of Jupiter’s mass. The exoplanet is about 200 light-years from Earth and takes less than six days to orbit its host star.

The amount of helium detected in the atmosphere of WASP-107b is so large that its upper atmosphere must extend tens of thousands of kilometres out into space. This also makes it the first time that an extended atmosphere has been discovered at infrared wavelengths. Since its atmosphere is so extended, the planet is losing a significant amount of its atmospheric gases into space — between ~0.1-4% of its atmosphere’s total mass every billion years

The important aspect of this detection is the use of infrared, which gives astronomers another tool to study exoplanets.

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SpaceX successfully launches NASA new exoplanet telescope

Capitalism in space: SpaceX today successfully placed NASA’s new explanet space telescope, TESS, into orbit.

The first stage, which was making its first flight, successfully landed on the drone ship in the Atlantic. They hope to reuse this booster on a future Dragon launch.

Update: TESS’s solar arrays have successfully deployed.

The leaders in the 2018 launch standings:

11 China
8 SpaceX
4 ULA
3 Japan
3 Russia
3 Europe
3 India

The U.S. is now ahead of China, 12 to 11, in the national list.

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The search for exoplanets at Alpha Centauri

The search for new exoplanets orbiting the three stars of the Alpha Centauri star system is intensifying, despite significant viewing challenges and solar activity that precludes life around one star.

The system’s two sunlike stars, Alpha Centauri A and B, orbit each other closely while Proxima Centauri, a tempestuous red dwarf, hangs onto the system tenuously in a much more distant orbit. In 2016, astronomers discovered an Earth-mass planet around Proxima Centauri, but the planet, blasted by radiation and fierce stellar winds, seems unlikely to be habitable. Astrobiologists think the other two stars are more likely to host temperate, Earth-like planets.

Maksym Lisogorskyi, an astronomer at the University of Hertfordshire in Hatfield, U.K., tried to find them with an instrument on the European Southern Observatory’s (ESO’s) 3.6-meter telescope in Chile. He and his colleagues looked for Doppler shifts in the spectral lines of the stars’ light that would be caused if a planet tugged them back and forth. But Lisogorskyi told the meeting that the stars’ surfaces are turbulent, and prone to flares that also jiggle the spectral lines, masking the subtle signals from any Earth-size planets. “The lines do all kinds of things,” he says. Although Alpha Centauri has been a primary target for the planet-finding instrument since it was inaugurated in 2005, it has seen nothing so far.

Also hampering observations are the current positions of the two stars. As viewed from Earth, they are very close together, making them harder to study individually, Lily Zhao of Yale University told the meeting. More precise observations should become possible as their 80-year orbit carries them farther apart. In the meantime, Zhao and her colleagues have succeeded in ruling out the presence of giant planets around either star, based on a decade’s worth of data from three instruments on different telescopes. “There are no Jupiters in the system, but there may be plenty of Earth-sized planets still to discover,” she said.

I am skeptical of the conclusions of the astrobiologists who think there may be habitable Earth-like planets in orbit around the close binary. Binary formation makes planetary formation difficult, and even if they are there the stars’ orbits would make stable orbits unlikely. Nonetheless, the research is good, as the techniques learned will be applicable elsewhere.

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Kepler to run out of fuel in the coming months

After nine years of success, the Kepler space telescope is running out of fuel, which will force an end to the mission sometime in the next several months.

The Kepler team is planning to collect as much science data as possible in its remaining time and beam it back to Earth before the loss of the fuel-powered thrusters means that we can’t aim the spacecraft for data transfer. We even have plans to take some final calibration data with the last bit of fuel, if the opportunity presents itself.

Without a gas gauge, we have been monitoring the spacecraft for warning signs of low fuel— such as a drop in the fuel tank’s pressure and changes in the performance of the thrusters. But in the end, we only have an estimate – not precise knowledge. Taking these measurements helps us decide how long we can comfortably keep collecting scientific data.

They are doing a dance here. If they run out of fuel while collecting data, that data will be lost. If they stop collecting data too soon, however, to transmit it to Earth, they will not maximize the data obtained.

Meanwhile, the next exoplanet hunter, TESS, is scheduled for launch on April 16 on a Falcon 9 rocket.

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More info on Trappist-1 solar system

Astronomers, using ground-based and orbiting telescopes, have obtained more information about the seven Earth-sized exoplanets that orbit the star Trappist-1 forty light years away.

First, a European effort has found that the planets probably all have loads of water.

A new study has found that the seven planets orbiting the nearby ultra-cool dwarf star TRAPPIST-1 are all made mostly of rock, and some could potentially hold more water than Earth. The planets’ densities, now known much more precisely than before, suggest that some of them could have up to 5 percent of their mass in the form of water — about 250 times more than Earth’s oceans. The hotter planets closest to their parent star are likely to have dense steamy atmospheres and the more distant ones probably have icy surfaces. In terms of size, density and the amount of radiation it receives from its star, the fourth planet out is the most similar to Earth. It seems to be the rockiest planet of the seven, and has the potential to host liquid water.

Data from the Hubble Space Telescope has meanwhile found that three of the seven planets do not have hydrogen in their atmospheres, which at first seems to contradict the European data.

The Hubble observations took advantage of the fact that the planets cross in front of their star every few days. Using the Wide Field Camera 3, astronomers made spectroscopic observations in infrared light, looking for the signature of hydrogen that would filter through a puffy, extended atmosphere, if it were present. “The planets are close enough to their host star, and they have very short orbital periods, which means there are lots of opportunities to make observations,” Lewis said.

Although Hubble did not find evidence of hydrogen, the researchers suspect the planetary atmospheres could have contained this lightweight gaseous element when they first formed. The planets may have formed farther away from their parent star in a colder region of the gaseous protostellar disk that once encircled the infant star.

The Hubble results are actually not very significant. They show only that they did not detect hydrogen in the atmospheres of these three exoplanets, which does not mean it isn’t there. Moreover, this Hubble press release appears to have been issued as much to sell the James Webb Space Telescope and to say that Hubble is looking at Trappist-1 also!

I should add that all of these results are very uncertain. We are looking at something that is very small and is also very far away. Any data obtained is certainly not a precise measurement of what is actually there, only a mere hint.

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New exoplanet makes eight in rival solar system

comparing solar systems

Worlds without end: Astronomers using Kepler data mined by computers have discovered an eighth planet in another solar system, making that system somewhat comparable to our own.

The newly discovered Kepler-90i — a sizzling hot, rocky planet orbiting its star once every 14.4 days — was found using computers that “learned” to find planets in data from NASA’s Kepler space telescope. Kepler finds distant planets beyond the solar system, or exoplanets, by detecting the minuscule change in brightness when a planet transits (crosses in front of) a star.

Vanderburg, a NASA Sagan fellow at UT Austin, and Shallue, a Google machine learning researcher, teamed up to train a computer to learn how to identify signs of an exoplanet in the light readings from distant stars recorded by Kepler. Similar to the way neurons connect in the human brain, this “neural network” sifted through the Kepler data to identify the weak transit signals from a previously missed eighth planet orbiting Kepler-90, a sun-like star 2,545 light-years from Earth in the constellation Draco. “For the first time since our solar system planets were discovered thousands of years ago, we know for sure that our solar system is not the sole record holder for the most planets,” Vanderburg said.

The image to the right compares the planet sizes between this solar system and ours. It does not show that, for this distant star, all eight planets have orbits closer to the star than the Earth, and would therefore be very unlikely to harbor life.

One more thing: This story is very cool, but it also is another one of those NASA press releases that the agency PR department overhyped beforehand, even allowing some reporters to think that it might involve the discovery of life beyond Earth. Not surprisingly, several news sources and radio shows asked me to talk about it. To their disappointment I said I’d rather wait, since NASA has overhyped more than a few stories like this in recent years. Once again, my instincts were right. This story has nothing to do with alien life, and though interesting, is actually not that big a deal.

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Astronomers find habitable Earth-mass planet 11 light years away

Worlds without end: Astronomers have found an Earth-mass planet 11 light years away, orbiting a quiet red dwarf star in the habitable zone.

Unlike Proxima Centauri, which periodically has large flares which make its Earth-sized planet less hospitable to life, this red dwarf, Ross 128, is more stable.

Many red dwarf stars, including Proxima Centauri, are subject to flares that occasionally bathe their orbiting planets in deadly ultraviolet and X-ray radiation. However, it seems that Ross 128 is a much quieter star, and so its planets may be the closest known comfortable abode for possible life.

Although it is currently 11 light-years from Earth, Ross 128 is moving towards us and is expected to become our nearest stellar neighbour in just 79 000 years — a blink of the eye in cosmic terms. Ross 128 b will by then take the crown from Proxima b and become the closest exoplanet to Earth!

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Astronomers find Kuiper Belt-like ring around Proxima Centauri

Worlds without end: Astronomers have found a dusty ring 1 to 4 astronomical units from the nearest star, Proxima Centauri.

Because Proxima Centauri is a smaller, dimmer star, its system is more compact. Proxima b [the star’s known exoplanet] circles the star at 0.05 astronomical units (a.u., the average distance between Earth and the Sun) — for reference, Mercury orbits the Sun at 0.39 a.u. The dusty ring lies well beyond that, extending from 1 to 4 a.u.

The Proxima ring is similar in some ways to the Kuiper Belt, a cold, dusty belt in the far reaches of our solar system (beyond 40 a.u.) that contains a fraction of Earth’s mass. While the Kuiper belt is well known for larger members such as Pluto and Eris, it also contains fine grains, ground down through collisions over billions of years. The dust ALMA observed around Proxima Centauri is composed of similar small grains. The average temperature and total mass of the Proxima ring is also about the same as our Kuiper Belt.

Because the ring here much closer to the star than our Kuiper Belt, the material is much more densely packed. Moreover, the presence of both a ring and an exoplanet suggests more planets might remain undiscovered there, increasing the chances that this star could have a solar system very worthwhile exploring.

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New exoplanet defies accepted theories of planet formation

The uncertainty of science: A newly discovered exoplanet, the size of Jupiter and orbiting a star half the size of the Sun, should not exist based on all the presently favored theories of planet formation.

New research, led by Dr Daniel Bayliss and Professor Peter Wheatley from the University of Warwick’s Astronomy and Astrophysics Group, has identified the unusual planet NGTS-1b – the largest planet compared to the size of its companion star ever discovered in the universe.

NGTS-1b is a gas giant six hundred light years away, the size of Jupiter, and orbits a small star with a radius and mass half that of our sun.

Its existence challenges theories of planet formation which state that a planet of this size could not be formed by such a small star. According to these theories, small stars can readily form rocky planets but do not gather enough material together to form Jupiter-sized planets. The planet is a hot Jupiter, at least as large as the Jupiter in our solar system, but with around 20% less mass. It is very close to its star – just 3% of the distance between Earth and the Sun – and orbits the star every 2.6 days, meaning a year on NGTS-1b lasts two and a half days.

No one should be surprised by this. While the present theories of planet formation are useful and necessary, giving scientists a rough framework for studying exoplanets, they should not be taken too seriously. We simply do not yet have enough information about how stars, solar systems, and planets form.

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Astronomers find 20 more exoplanet candidates in Kepler archive

Worlds without end: Astronomers reviewing the Kepler archive have found 20 more exoplanet candidates, including one that has a mass about 97 percent of the Earth with an orbit 395 days long circling a star like the Sun.

The planet would be colder than Earth, as its star is slightly cooler than the Sun, and its orbit is slightly farther away. Nonetheless, this is an amazing twin, and would certainly be a prime target when interstellar travel becomes routine.

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Astronomers search for water on Trappist-1 ecoplanets

The uncertainty of science: New research suggests that the Earth-sized exoplanets circling Trappist-1 might have water, or might not.

The data suggests the inner planets likely have lost all their water, but the outer planets, some of which are in the habitable zone, could have water. The key word is “could.” They actually don’t yet have any data that says for sure whether water is there..

Posted as we drive through Kayenta in the Navaho Reservation.

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Have astronomers using Kepler discovered the first exomoon?

The uncertainty of science: Using data from Kepler astronomers think they have spotted the first exomoon, orbiting a star 4,000 light years away.

They think it might be the size of Neptune, and orbits a planet about ten times more massive than Jupiter.

All this is unconfirmed, however, especially because their conclusions are based on data from only three transits. They plan to use the Hubble Space Telescope to do more observations and hopefully confirm the discovery.

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Update of Kepler exoplanet catalog

Worlds without end: The Kepler science team has released an update of the space telescope’s exoplanet candidate list, adding 219 new exoplanet candidates.

NASA’s Kepler space telescope team has released a mission catalog of planet candidates that introduces 219 new planet candidates, 10 of which are near-Earth size and orbiting in their star’s habitable zone, which is the range of distance from a star where liquid water could pool on the surface of a rocky planet. This is the most comprehensive and detailed catalog release of candidate exoplanets, which are planets outside our solar system, from Kepler’s first four years of data. It’s also the final catalog from the spacecraft’s view of the patch of sky in the Cygnus constellation.

With the release of this catalog, derived from data publicly available on the NASA Exoplanet Archive, there are now 4,034 planet candidates identified by Kepler. Of which, 2,335 have been verified as exoplanets. Of roughly 50 near-Earth size habitable zone candidates detected by Kepler, more than 30 have been verified.

Additionally, results using Kepler data suggest two distinct size groupings of small planets. Both results have significant implications for the search for life. The final Kepler catalog will serve as the foundation for more study to determine the prevalence and demographics of planets in the galaxy, while the discovery of the two distinct planetary populations shows that about half the planets we know of in the galaxy either have no surface, or lie beneath a deep, crushing atmosphere – an environment unlikely to host life.

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Exoplanet hotter than some stars

Astronomers have identified an Jupiter-sized exoplanet with a surface that is apparently hotter than the surfaces of some stars.

With a day-side temperature of 4,600 Kelvin (more than 7,800 degrees Fahrenheit), planet KELT-9b is hotter than most stars, and only 1,200 Kelvin (about 2,000 degrees Fahrenheit) cooler than our own sun…. 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. And 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 is so hot that molecules such as water, carbon dioxide, and methane can’t form there. The properties of the night side are still mysterious—molecules may be able to form there, but probably only temporarily.

The most interesting aspect of this discovery is that it was done with small, inexpensive ground-based telescopes.

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Astronomers find that Epsilon Eridani solar system resembles our own system

New data of the Epsilon Eridani solar system 10.5 light years away confirms that its debris disk has a structure somewhat resembling our own solar system.

The data has found that the debris disk has two narrow belts, one located at about the same distance from the star as our asteroid belt, and the other orbiting at about where Uranus is located. In addition, the system appears to have a Jupiter-sized planet orbiting the same distance from the star as does Jupiter.

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Citizen scientists crowd scource discovery of 4 exoplanets

After being promoted on an Australian tv show an effort to use public help to plow through Kepler’s vast archives discovered four new exoplanets within two days.

In three days, the Australia iteration of astronomy TV show Stargazing Live brought us #SpaceGandalf and now its viewers have discovered four planets. After it was promoted on the show, citizen scientists and fans of the program came together to contribute to a crowd-sourcing project, stalking around 100,000 stars on the Zooniverse website, which displays recent data from the Kepler Space Telescope.

And you betcha, in just 48 hours, around 10,000 volunteers discovered scores of potential new planet candidates, with scientists confirming the discovery of four “super-Earth” planets orbiting a star in the constellation of Aquarius.

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