The four new, but as yet unconfirmed, exoplanets. Image: University of British Columbia
A student at the University of British Columbia (UBC), Canada, has discovered four new exoplanets hidden in data from the Kepler spacecraft.
Michelle Kunimoto recently graduated from UBC with a Bachelor’s degree in physics and astronomy. As part of her coursework, she spent a few months looking closely at Kepler data, trying to find planets that others had overlooked.
In the end, she discovered four planets, (or planet candidates until they are independently confirmed.) The first planet is the size of Mercury, two are roughly Earth-sized, and one is slightly larger than Neptune. According to Kunimoto, the largest of the four, called KOI (Kepler Object of Interest) 408.05, is the most interesting. That one is 3,200 light years away from Earth and occupies the habitable zone of its star.
“Like our own Neptune, it’s unlikely to have a rocky surface or oceans,” said Kunimoto, who graduates today from UBC. “The exciting part is that like the large planets in our solar system, it could have large moons and these moons could have liquid water oceans.”
Her astronomy professor, Jaymie Matthews, shares her enthusiasm. “Pandora in the movie Avatar was not a planet, but a moon of a giant planet,” he said. And we all know what lived there.
On its initial mission, Kepler looked at 150,000 stars in the Milky Way. Kepler looks for dips in the brightness of these stars, which can be caused by planets passing between us and the star. These dips are called light curves, and they can tell us quite a bit about an exoplanet.
“A star is just a pinpoint of light so I’m looking for subtle dips in a star’s brightness every time a planet passes in front of it,” said Kunimoto. “These dips are known as transits, and they’re the only way we can know the diameter of a planet outside the solar system.”
Michelle Kunimoto and her prof., Jaymie Matthews, at the University of British Columbia in Vancouver, Canada. Image: Martin Dee/UBC
One of the limitations of the Kepler mission is that it’s biased against planets that take a long time to orbit their star. That’s because the longer the orbit is, the fewer transits can be witnessed in a given amount of time. The “warm Neptune” KOI 408.05 found by Kunimoto takes 637 days to orbit its sun.
This long orbit explains why the planet was not found initially, and also why Kunimoto is receiving recognition for her discovery. It took a substantial commitment and effort to uncover it. Kepler has discovered almost 5,000 planet and planet candidates, and of those, only 20 have longer orbits than KOI 408.05.
Kunimoto and Matthews have submitted the findings to the Astronomical Journal. They may be the first of many submissions for Kunimoto, as she is returning to UBC next year to earn a Master’s Degree in physics and astronomy, when she will hunt for more planets and investigate their habitability.
The fun didn’t end with her exoplanet discovery, however. As a Star Trek fan (who isn’t one?) she was lucky enough to meet William Shatner at an event at the University, and to share her discovery with Captain James Tiberius Kirk.
It makes you wonder what other surprises might lie hidden in the Kepler data, and what else might be uncovered. Might a life-bearing planet or moon, maybe the only one, be found in Kepler’s data at some future time?
In this rare view, the James Webb Space Telescope team crane lifted the science instrument package for installation into the telescope structure. Credits: NASA/Chris Gunn
In this rare view, the James Webb Space Telescope team crane lifted the science instrument package for installation into the telescope structure. Credits: NASA/Chris Gunn
A team of two dozen engineers and technicians working with “surgical precision” inside the world’s largest clean room at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, meticulously guided the instrument package known as the ISIM (Integrated Science Instrument Module) into the telescope truss structure.
The ISIM holds the observatory’s international quartet of state-of-the-art research instruments, funded, built and provided by research teams in the US, Canada and Europe.
“This is a tremendous accomplishment for our worldwide team,” said John Mather, James Webb Space Telescope Project Scientist and Nobel Laureate, in a statement.
“There are vital instruments in this package from Europe and Canada as well as the US and we are so proud that everything is working so beautifully, 20 years after we started designing our observatory.”
This side shot shows a glimpse inside a massive clean room at NASA’s Goddard Space Flight Center in Greenbelt, Maryland where the James Webb Space Telescope team worked meticulously to complete the science instrument package installation. Credits: NASA/Desiree Stover
Just as with the mirrors installation and other assembly tasks, the technicians practiced the crucial ISIM installation procedure numerous times via test runs, computer modeling and a mock-up of the instrument package.
To accomplish the ISIM installation, the telescope structure had to be flipped over and placed into the giant work gantry in the clean room to enable access by the technicians.
“The telescope structure has to be turned over and put into the gantry system [in the clean room],” said John Durning, Webb Telescope Deputy Project Manager, in an exclusive interview with Universe Today at NASA’s Goddard Space Flight Center.
“Then we take ISIM and install in the back of the telescope.”
The team used an overhead crane to lift and maneuver the heavy ISIM science instrument package in the clean room. Then they lowered it into the enclosure behind the mirrors on the telescopes backside and secured it to the structure.
“Our personnel were navigating a very tight space with very valuable hardware,” said Jamie Dunn, ISIM Manager.
“We needed the room to be quiet so if someone said something we would be able to hear them. You listen not only for what other people say, but to hear if something doesn’t sound right.”
Up close view shows cone shaped Aft Optics Subsystem (AOS) standing at center of Webb telescopes 18 segment primary mirror at NASA’s Goddard Space Flight Center in Greenbelt, Maryland on May 3, 2016. ISIM science instrument module will be installed inside truss structure below. Credit: Ken Kremer/kenkremer.com
The ISIM installation continues the excellently executed final assembly phase of Webb at Goddard this year. And comes just weeks after workers finished installing the entire mirror system.
This author has witnessed and reported on the assembly progress at Goddard on numerous occasions, including after the mirrors were recently uncovered and unveiled in all their golden glory.
“The entire mirror system is checked out. The system has been integrated and the alignment has been checked,” said John Durning, Webb Telescope Deputy Project Manager, in an exclusive interview with Universe Today at NASA’s Goddard Space Flight Center.
Up close side-view of newly exposed gold coated primary mirrors installed onto mirror backplane holding structure of NASA’s James Webb Space Telescope inside the massive clean room at NASA’s Goddard Space Flight Center in Greenbelt, Maryland on May 3, 2016. Aft optics subsystem stands upright at center of 18 mirror segments between stowed secondary mirror mount booms. Credit: Ken Kremer/kenkremer.com
ISIM is a collection of cameras and spectrographs that will record the light collected by Webb’s giant golden primary mirror.
“It will take us a few months to install ISIM and align it and make sure everything is where it needs to be,” Durning told me.
The primary mirror is comprised of 18 hexagonal segments.
Each of the 18 hexagonal-shaped primary mirror segments measures just over 4.2 feet (1.3 meters) across and weighs approximately 88 pounds (40 kilograms). They are made of beryllium, gold coated and about the size of a coffee table.
Webb’s golden mirror structure was tilted up for a very brief period on May 4 as seen in this NASA time-lapse video:
The 18-segment primary mirror of NASA’s James Webb Space Telescope was raised into vertical alignment in the largest clean room at the agency’s Goddard Space Flight Center in Greenbelt, Maryland, on May 4, 2016. Credit: NASA
The gargantuan observatory will significantly exceed the light gathering power of NASA’s Hubble Space Telescope (HST) – currently the most powerful space telescope ever sent to space.
With the mirror structure complete, the next step was the ISIM science module installation.
To accomplish that installation, technicians carefully moved the Webb mirror structure into the clean room gantry structure.
As shown in this time-lapse video we created from Webbcam images, they tilted the structure vertically, flipped it around, lowered it back down horizontally and then transported it via an overhead crane into the work platform.
Time-lapse showing the uncovered 18-segment primary mirror of NASA’s James Webb Space Telescope being raised into vertical position, flipped and lowered upside down to horizontal position and then moved to processing gantry in the largest clean room at the agency’s Goddard Space Flight Center in Greenbelt, Maryland, on May 4/5, 2016. Images: NASA Webbcam. Time-lapse by Ken Kremer/kenkremer.com/Alex Polimeni
The telescope will launch on an Ariane V booster from the Guiana Space Center in Kourou, French Guiana in 2018.
The Webb Telescope is a joint international collaborative project between NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA).
Webb is designed to look at the first light of the Universe and will be able to peer back in time to when the first stars and first galaxies were forming. It will also study the history of our universe and the formation of our solar system as well as other solar systems and exoplanets, some of which may be capable of supporting life on planets similar to Earth.
All 18 gold coated primary mirrors of NASA’s James Webb Space Telescope are seen fully unveiled after removal of protective covers installed onto the backplane structure, as technicians work inside the massive clean room at NASA’s Goddard Space Flight Center in Greenbelt, Maryland on May 3, 2016. The secondary mirror mount booms are folded down into stowed for launch configuration. Credit: Ken Kremer/kenkremer.com
More about ISIM and upcoming testing in the next story.
Watch this space for my ongoing reports on JWST mirrors, science, construction and testing.
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
Exoplanet Kepler 62f would need an atmosphere rich in carbon dioxide for water to be in liquid form. Artist's Illustration: NASA Ames/JPL-Caltech/T. Pyle
A team of astronomers suggests that an exoplanet named 62f could be habitable. Kepler data suggests that 62f is likely a rocky planet, and could have oceans. The exoplanet is 40% larger than Earth and is 1200 light years away.
62f is part of a planetary system discovered by the Kepler mission in 2013. There are 5 planets in the system, and they orbit a star that is both cooler and smaller than our Sun. The target of this study, 62f, is the outermost of the planets in the system.
Kepler can’t tell us if a planet is habitable or not. It can only tell us something about its potential habitability. The team, led by Aomawa Shields from the UCLA department of physics and astronomy, used different modeling methods to determine if 62f could be habitable, and the answer is, maybe.
According to the study, much of 62f’s potential habitability revolves around the CO2 component of its atmosphere, if it indeed has an atmosphere. As a greenhouse gas, CO2 can have a significant effect on the temperature of a planet, and hence, a significant effect on its habitability.
Earth’s atmosphere is only 0.04% carbon dioxide (and rising.) 62f would likely need to have much more CO2 than that if it were to support life. It would also require other atmospheric characteristics, .
The study modelled parameters for CO2 concentration, atmospheric density, and orbital characteristics. They simulated:
An atmospheric thickness from the same as Earth’s up to 12 times thicker.
Carbon dioxide concentrations ranging from the same as Earth’s up to 2500 times Earth’s level.
Multiple different orbital configurations.
It may look like the study casts its net pretty wide in order to declare a planet potentially habitable. But the simulations were pretty robust, and relied on more than a single, established modelling method to produce these results. With that in mind, the team found that there are multiple scenarios that could make 62f habitable.
“We found there are multiple atmospheric compositions that allow it to be warm enough to have surface liquid water,” said Shields, a University of California President’s Postdoctoral Program Fellow. “This makes it a strong candidate for a habitable planet.”
Our dear, sweet Earth is the only planet where life is confirmed. Here it is, as seen on July 6, 2015 from a distance of one million miles by a NASA scientific camera aboard the Deep Space Climate Observatory spacecraft. Credits: NASA
As mentioned earlier, CO2 concentration is a big part of it. According to Shields, the planet would need an atmospheric entirely composed of CO2, and an atmosphere five times as dense as Earth’s to be habitable through its entire year. That means that there would be 2500 times more carbon dioxide than Earth has. This would work because the planet’s orbit may take it far enough away from the star for water to freeze, but an atmosphere this dense and this high in CO2 would keep the planet warm.
But there are other conditions that would make 62f habitable, and these include the planet’s orbital characteristics.
“But if it doesn’t have a mechanism to generate lots of carbon dioxide in its atmosphere to keep temperatures warm, and all it had was an Earth-like amount of carbon dioxide, certain orbital configurations could allow Kepler-62f’s surface temperatures to temporarily get above freezing during a portion of its year,” said Shields. “And this might help melt ice sheets formed at other times in the planet’s orbit.”
Shields and her team used multiple modelling methods to produce these results. The climate was modelled using the Community Climate System Model and the Laboratoire de Me´te´orologie Dynamique Generic model. The planet’s orbital characteristics were modelled using HNBody. This study represents the first time that these modelling methods were combined, and this combined method can be used on other planets.
Shields said, “This will help us understand how likely certain planets are to be habitable over a wide range of factors, for which we don’t yet have data from telescopes. And it will allow us to generate a prioritized list of targets to follow up on more closely with the next generation of telescopes that can look for the atmospheric fingerprints of life on another world.”
There are over 2300 confirmed exoplanets, and many more candidates yet to be confirmed. Only a handful of them have been confirmed as being in the habitable zone around their host star. Of course, we don’t know if life can exist on other planets, even if they do reproduce the same kind of habitability that Earth has. We just have no way of knowing, yet.
That will change when instruments like the James Webb Space Telescope are able to peer into the atmospheres of exoplanets and tell us something about any bio-markers that might be present.
But until then, and until we actually visit another world with a probe of some design, we need to use modelling like the type employed in this study, to get us closer to answering the question of life on other worlds.
Artist's impression of rocky exoplanets orbiting Gliese 832, a red dwarf star just 16 light-years from Earth. Credit: ESO/M. Kornmesser/N. Risinger (skysurvey.org).
Three more potentially Earthlike worlds have been discovered in our galactic backyard, announced online today by the European Southern Observatory. Researchers using the 60-cm TRAPPIST telescope at ESO’s La Silla observatory in Chile have identified three Earth-sized exoplanets orbiting a star just 40 light-years away.
The star, originally classified as 2MASS J23062928-0502285 but now known more conveniently as TRAPPIST-1, is a dim “ultracool” red dwarf star only .05% as bright as our Sun . Located in the constellation Aquarius, it’s now the 37th-farthest star known to host orbiting exoplanets.
The exoplanets were discovered via the transit method (TRAPPIST stands for Transiting Planets and Planetesimals Small Telescope) through which the light from a star is observed to dim slightly by planets passing in front of it from our point of view. This is the same method that NASA’s Kepler spacecraft has used to find over 1,000 confirmed exoplanets.
Location of TRAPPIST-1 in the constellation Aquarius. Credit: ESO/IAU and Sky & Telescope.
As an ultracool dwarf TRAPPIST-1 is a very small and dim and isn’t easily visible from Earth, but it’s its very dimness that has allowed its planets to be discovered with existing technology. Their subtle silhouettes may have been lost in the glare of larger, brighter stars.
Follow-up measurements of the three exoplanets indicated that they are all approximately Earth-sized and have temperatures ranging from Earthlike to Venuslike (which is, admittedly, a fairly large range.) They orbit their host star very closely with periods measured in Earth days, not years.
“With such short orbital periods, the planets are between 20 and 100 times closer to their star than the Earth to the Sun,” said Michael Gillon, lead author of the research paper. “The structure of this planetary system is much more similar in scale to the system of Jupiter’s moons than to that of the Solar System.”
Structure of the TRAPPIST-1 exosystem. The green is the star’s habitable zone. Credit: PHL.
Although these three new exoplanets are Earth-sized they do not yet classify as “potentially habitable,” at least by the standards of the Planetary Habitability Laboratory (PHL) operated by the University of Puerto Rico at Arecibo. The planets fall outside PHL’s required habitable zone; two are too close to the host star and one is too far away.
In addition there are certain factors that planets orbiting ultracool dwarfs would have to contend with in order to be friendly to life, not the least of which is the exposure to energetic outbursts from solar flares.
This does not guarantee that the exoplanets are completely uninhabitable, though; it’s entirely possible that there are regions on or within them where life could exist, not unlike Mars or some of the moons in our own Solar System.
The exoplanets are all likely tidally locked in their orbits, so even though the closest two are too hot on their star-facing side and too cold on the other, there may be regions along the east or west terminators that maintain a climate conducive to life.
“Now we have to investigate if they’re habitable,” said co-author Julien de Wit at MIT in Cambridge, Mass. “We will investigate what kind of atmosphere they have, and then will search for biomarkers and signs of life.”
Artist’s impression of the view from the most distant exoplanet discovered around the dwarf star TRAPPIST-1. Credit: ESO/M. Kornmesser.
Discovering three planets orbiting such a small yet extremely common type of star hints that there are likely many, many more such worlds in our galaxy and the Universe as a whole.
“So far, the existence of such ‘red worlds’ orbiting ultra-cool dwarf stars was purely theoretical, but now we have not just one lonely planet around such a faint red star but a complete system of three planets,” said study co-author Emmanuel Jehin.
The team’s research was presented in a paper entitled “Temperate Earth-sized planets transiting a nearby ultracool dwarf star” and will be published in Nature.
Note: the original version of this article described 2MASS J23062928-0502285 (TRAPPIST-1) as a brown dwarf based on its classification on the Simbad archive. But at M8V it is “definitely a star,” according to co-author Julien de Wit in an email, although at the very low end of the red dwarf line. Corrections have been made above.
An exoplanet seen from its moon (artist's impression). Via the IAU.
Is there life on other planets, somewhere in this enormous Universe? That’s probably the most compelling question we can ask. A lot of space science and space missions are pointed directly at that question.
The Kepler mission is designed to find exoplanets, which are planets orbiting other stars. More specifically, its aim is to find planets situated in the habitable zone around their star. And it’s done so. The Kepler mission has found 297 confirmed and candidate planets that are likely in the habitable zone of their star, and it’s only looked at a tiny patch of the sky.
But we don’t know if any of them harbour life, or if Mars ever did, or if anywhere ever did. We just don’t know. But since the question of life elsewhere in the Universe is so compelling, it’s driven people with intellectual curiosity to try and compute the likelihood of life on other planets.
One of the main ways people have tried to understand if life is prevalent in the Universe is through the Drake Equation, named after Dr. Frank Drake. He tried to come up with a way to compute the probability of the existence of other civilizations. The Drake Equation is a mainstay of the conversation around the existence of life in the Universe.
The Drake Equation is a way to calculate the probability of extraterrestrial civilizations in the Milky Way that were technologically advanced to communicate. When it was created in 1961, Drake himself explained that it was really just a way of starting a conversation about extraterrestrial civilizations, rather than a definitive calculation. Still, the equation is the starting point for a lot of conversations.
But the problem with the Drake equation, and with all of our attempts to understand the likelihood of life starting on other planets, is that we only have the Earth to go by. It seems like life on Earth started pretty early, and has been around for a long time. With that in mind, people have looked out into the Universe, estimated the number of planets in habitable zones, and concluded that life must be present, and even plentiful, in the Universe.
But we really only know two things: First, life on Earth began a few hundred million years after the planet was formed, when it was sufficiently cool and when there was liquid water. The second thing that we know is that a few billions of years after life started, creatures appeared which were sufficiently intelligent enough to wonder about life.
In 2012, two scientists published a paper which reminded us of this fact. David Spiegel, from Princeton University, and Edwin Turner, from the University of Tokyo, conducted what’s called a Bayesian analysis on how our understanding of the early emergence of life on Earth affects our understanding of the existence of life elsewhere.
A Bayesian analysis is a complicated matter for non-specialists, but in this paper it’s used to separate out the influence of data, and the influence of our prior beliefs, when estimating the probability of life on other worlds. What the two researchers concluded is that our prior beliefs about the existence of life elsewhere have a large effect on any probabilistic conclusions we make about life elsewhere. As the authors say in the paper, “Life arose on Earth sometime in the first few hundred million years after the young planet had cooled to the point that it could support water-based organisms on its surface. The early emergence of life on Earth has been taken as evidence that the probability of abiogenesis is high, if starting from young-Earth-like conditions.”
A key part of all this is that life may have had a head start on Earth. Since then, it’s taken about 3.5 billion years for creatures to evolve to the point where they can think about such things. So this is where we find ourselves; looking out into the Universe and searching and wondering. But it’s possible that life may take a lot longer to get going on other worlds. We just don’t know, but many of the guesses have assumed that abiogenesis on Earth is standard for other planets.
What it all boils down to, is that we only have one data point, which is life on Earth. And from that point, we have extrapolated outward, concluding hopefully that life is plentiful, and we will eventually find it. We’re certainly getting better at finding locations that should be suitable for life to arise.
What’s maddening about it all is that we just don’t know. We keep looking and searching, and developing technology to find habitable planets and identify bio-markers for life, but until we actually find life elsewhere, we still only have one data point: Earth. But Earth might be exceptional.
As Spiegel and Turner say in the conclusion of their paper, ” In short, if we should find evidence of life that arose wholly idependently of us – either via astronomical searches that reveal life on another planet or via geological and biological studies that find evidence of life on Earth with a different origin from us – we would have considerably stronger grounds to conclude that life is probably common in our galaxy.”
With our growing understanding of Mars, and with missions like the James Webb Space Telescope, we may one day soon have one more data point with which we can refine our probabilistic understanding of other life in the Universe.
Or, there could be a sadder outcome. Maybe life on Earth will perish before we ever find another living microbe on any other world.
An artistic representation of Gliese 832 c against a stellar nebula background. A new paper says Gliese 832 might be home to another planet similar to this, but in the habitable zone. Credit: Planetary Habitability Laboratory at the University of Puerto Rico, Arecibo, NASA/Hubble, Stellarium.
Earth may have a new neighbour, in the form of an Earth-like planet in a solar system only 16 light years away. The planet orbits a star named Gliese 832, and that solar system already hosts two other known exoplanets: Gliese 832B and Gliese 832C. The findings were reported in a new paper by Suman Satyal at the University of Texas, and colleagues J. Gri?th, and Z. E. Musielak.
Gliese 832B is a gas giant similar to Jupiter, at 0.64 the mass of Jupiter, and it orbits its star at 3.5 AU. G832B probably plays a role similar to Jupiter in our Solar System, by setting gravitational equilibrium. Gliese 832C is a Super-Earth about 5 times as massive as Earth, and it orbits the star at a very close 0.16 AU. G832C is a rocky planet on the inner edge of the habitable zone, but is likely too close to its star for habitability. Gliese 832, the star at the center of it all, is a red dwarf about half the size of our Sun, in both mass and radius.
The newly discovered planet is still hypothetical at this point, and the researchers put its mass at between 1 and 15 Earth masses, and its orbit at between 0.25 to 2.0 AU from Gliese 582, its host star.
The two previously discovered planets in Gliese 832 were discovered using the radial velocity technique. Radial velocity detects planets by looking for wobbles in the host star, as it responds to the gravitational tug exerted on it by planets in orbit. These wobbles are observable through the Doppler effect, as the light of the affected star is red-shifted and blue-shifted as it moves.
The team behind this study re-analyzed the data from the Gliese 832 system, based on the idea that the vast distance between the two already-detected planets would be home to another planet. According to other solar systems studied by Kepler, it would be highly unusual for such a gap to exist.
As they say in their paper, the main thrust of the study is to explore the gravitational effect that the large outer planet has on the smaller inner planet, and also on the hypothetical Super-Earth that may inhabit the system. The team conducted numerical simulations and created models constrained by what’s known about the Gliese 832 system to conclude that an Earth-like planet may orbit Gliese 832.
This can all sound like some hocus-pocus in a way, as my non-science-minded friends like to point out. Just punch in some numbers until it shows an Earth-like planet, then publish and get attention. But it’s not. This kind of modelling and simulation is very rigorous.
Putting in all the data that’s known about the Gliese 832 system, including radial velocity data, orbital inclinations, and gravitational relationships between the planets and the star, and between the planets themselves, yields bands of probability where previously undetected planets might exist. This result tells planet hunters where to start looking for planets.
In the case of this paper, the result indicates that “there is a slim window of about 0.03 AU where an Earth-like planet could be stable as well as remain in the HZ.” The authors are quick to point out that the existence of this planet is not proven, only possible.
The other planets were found using the radial velocity method, which is pretty reliable. But radial velocity only provides clues to the existence of planets, it doesn’t prove that they’re there. Yet. The authors acknowledge that a larger number of radial velocity observations are needed to confirm the existence of this new planet. Barring that, either the transit method employed by the Kepler spacecraft, or direct observation with powerful telescopes, may also provide positive proof.
So far, the Kepler spacecraft has confirmed the existence of 1,041 planets. But Kepler can’t look everywhere for planets. Studies like these are crucial in giving Kepler starting points in its search for exoplanets. If an exoplanet can be confirmed in the Gliese 832 system, then it also confirms the accuracy of the simulation that the team behind this paper performed.
If confirmed, G832 C would join a growing list of exoplanets. It wasn’t long ago that we knew almost nothing about other solar systems. We only had knowledge of our own. And even though it was always unlikely that our Solar System would for some reason be special, we had no certain knowledge of the population of exoplanets in other solar systems.
Studies like this one point to our growing understanding of the dynamics of other solar systems, and the population of exoplanets in the Milky Way, and most likely throughout the cosmos.
Artist's impression of Planet Nine, blocking out the Milky Way. The Sun is in the distance, with the orbit of Neptune shown as a ring. Credit: ESO/Tomruen/nagualdesign
One of the biggest new mysteries in our Solar System is the purported presence of a large and distant “Planet Nine,” traveling around the Sun in a twenty-thousand-year orbit far beyond Pluto. Although this far-flung world’s existence has yet to actually be confirmed (or even directly detected) some scientists are suggesting it might have originally been an exoplanet around a neighboring star, pilfered by our Sun during its impudent adolescence.
Illustration of the hot extrasolar planet 2M1207b orbiting a brown dwarf. Credits: NASA, ESA, and G. Bacon/STScI
Astronomers using the Hubble Space Telescope have measured the rotation rate of an extreme exoplanet 2M1207b by observing the varied brightness in its atmosphere. This is the first measurement of the rotation of a massive exoplanet using direct imaging.
This is a composite image of the brown dwarf object 2M1207 (blue-white) and the planet 2M1207b, seen in red, located 170 light years from Earth in the constellation Centaurus. The photo is based on three near-infrared exposures with the taken with the 8.2-m VLT Yepun telescope at the ESO Paranal Observatory. Credit: ESO
Little by little we’re coming to know at least some of the 2,085 exoplanets discovered to date more intimately despite their great distances and proximity to the blinding light of their host stars. 2M1207b is about four times more massive than Jupiter and dubbed a “super-Jupiter”. Super-Jupiters fill the gap between Jupiter-mass planets and brown dwarf stars. They can be up to 80 times more massive than Jupiter yet remain nearly the same size as that planet because gravity compresses the material into an ever denser, more compact sphere.
2M1207b lies 170 light years from Earth and orbits a brown dwarfat a distance of 5 billion miles. By contrast, Jupiter is approximately 500 million miles from the sun. You’ll often hear brown dwarfs described as “failed stars” because they’re not massive enough for hydrogen fusion to fire up in their cores the way it does in our sun and all the rest of the main sequence stars.
Researchers used Hubble’s exquisite resolution to precisely measure the planet’s brightness changes as it spins and nailed the rotation rate at 10 hours, virtually identical to Jupiter’s. While it’s fascinating to know a planet’s spin, there’s more to this extraordinary exoplanet. Hubble data confirmed the rotation but also showed the presence of patchy, “colorless” (white presumably) cloud layers. While perhaps ordinary in appearance, the composition of the clouds is anything but.
Exoplanet 2M1207 b with the Solar System planet Jupiter for comparison. Although four times more massive than the Jovian planet, gravity compresses its matter to keep it relatively small. Credit: Wikipedia / Aldaron
The planet appears bright in infrared light because it’s young (about 10 million years old) and still contracting, releasing gravitational potential energy that heats it from the inside out. All that extra heat makes 2M1207b’s atmosphere hot enough to form “rain” clouds made of vaporized rock. The rock cools down to form tiny particles with sizes similar to those in cigarette smoke. Deeper into the atmosphere, iron droplets are forming and falling like rain, eventually evaporating as they enter the lower levels of the atmosphere.
“So at higher altitudes it rains glass, and at lower altitudes it rains iron,” said Yifan Zhou of the University of Arizona, lead author on the research paper in a recent Astrophysical Journal. “The atmospheric temperatures are between about 2,200 to 2,600 degrees Fahrenheit.” Every day’s a scorcher on 2M1207b.
Both Jupiter and Saturn also emit more heat than they receive from the sun because they too are still contracting despite being 450 times older. The bigger you are, the slower you chill.
Illustration of the extrasolar planet 2M1207b (foreground) orbiting a brown dwarf. Both shine brightly in infrared light. Credits: NASA, ESA, and G. Bacon/STScI
All the planets in our Solar System possess only a fraction of the mass of the Sun. Even mighty Jove is a thousand times less massive. But Mr. Super-Jupiter’s a heavyweight compared to its brown dwarf host, being just 5-7 times less massive. While Jupiter and the rest of the planets formed by the accretion of dust and rocks within a clumpy disk of material surrounding the early Sun, it’s thought 2M1207b and its companion may have formed throughout the gravitational collapse of a pair of separate disks.
This super-Jupiter will an ideal target for the James Webb Space Telescope, a space observatory optimized for the infrared scheduled to launch in 2018. With its much larger mirror — 21-feet (6.5-meters) — Webb will help astronomers better determine the exoplanet’s atmospheric composition and created more detailed maps from brightness changes.
Teasing out the details of 2M1207b’s atmosphere and rotation introduces us to a most alien world the likes of which never evolved in our own Solar System. I feel like I’m aboard the Starship Enterprise visiting far-flung worlds. Only this is better. It’s real.
A new paper says that a Super-Earth may have formed in our Solar System and been swallowed by the Sun. Image Credit: ESA/Hubble, M. Kornmesser
55 Cancri-e was once touted as one of the most exotic exo-planets ever discovered. Mass and radius modelling led some astronomers to speculate that its interior could be rich in carbon. And that much carbon crushed together under extreme pressure = diamonds. That’s how it got its nickname “Diamond Planet.”
But 55 Cancri-e—now named “Janssen” (Thank you International Astronomical Union!)—is even more exotic with the recent discovery of an atmosphere. A February 7th research paper in the Astrophysical Journal, by a team of European astronomers, reports that Janssen has an atmosphere rich in hydrogen. This makes Janssen the first exo-planet, that we know of, to have an atmosphere.
The team used the Wide Field Camera 3 (WDF3) on the Hubble Space Telescope, and a new scanning technique, to gain an understanding of Janssen’s atmosphere. Along with hydrogen, the team also found helium, and potentially, hydrogen cyanide.
Given Janssen’s surface temperature of 2000 K (1727 C), and its proximity to its host star, the existence of an atmosphere is surprising. The team suspects that the hydrogen-rich atmosphere is left over from the planet’s formation 8 billion years ago, and is a remnant of the nebula that the planet and star formed from.
“Our observations of 55 Cancri e’s atmosphere suggest that the planet has managed to cling on to a significant amount of hydrogen and helium from the nebula from which it formed,” said Angelos Tsiaras, a PhD student at UCL, who helped develop the new scanning technique. “This is a very exciting result because it’s the first time that we have been able to find the spectral fingerprints that show the gases present in the atmosphere of a super-Earth.”
Super-Earths are the most common type of planet in our galaxy, though none exist in our solar system. They are called super-Earths because they have more mass than Earth, but are smaller than the gas giants. A greater understanding of super-Earths should mean a greater understanding of the most common type of planet around.
“This result gives a first insight into the atmosphere of a super-Earth. We now have clues as to what the planet is currently like, how it might have formed and evolved, and this has important implications for 55 Cancri e and other super-Earths,” said Professor Giovanna Tinetti of UCL.
The existence of hydrogen cyanide in Janssen’s atmosphere is also significant. Its presence indicates a carbon-rich atmosphere. This supports the idea that Janssen is a diamond planet, though that conclusion is still far from certain. “If the presence of hydrogen cyanide and other molecules is confirmed in a few years time by the next generation of infrared telescopes, it would support the theory that this planet is indeed carbon rich and a very exotic place,” said Professor Jonathan Tennyson, UCL.
The team has used their new technique on 2 other super-Earths, but no atmosphere was found.
55-Cancri e is about 40 light years from Earth. Its host star is slightly smaller, cooler, and a little dimmer than our Sun, and its year is shorter than an Earth day.
This overhead shot of the James Webb Space Telescope shows part of the installation of the 18 primary flight mirrors onto the telescope structure in a clean room at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Credits: NASA’s Goddard Space Flight Center/Chris Gunn
See time-lapse video below
This overhead shot of the James Webb Space Telescope shows part of the installation of the 18 primary flight mirrors onto the telescope structure in a clean room at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Credits: NASA’s Goddard Space Flight Center/Chris Gunn See time-lapse video below
NASA GODDARD SPACE FLIGHT CENTER, MD – A time-lapse video newly released by NASA documents the painstakingly complex assembly of the primary mirror at the heart of the biggest space telescope ever conceived by humankind – NASA’s James Webb Space Telescope (JWST).
