KELT-9b won the metal for hottest exoplanet at more than 6,800°F, and now scientists have detected iron and titanium in its atmosphere in a first for science. Buzz60 </s> KELT-9b is exoplanet 650 light years from Earth, orbiting its host star at a distance of just 6 million kilometres or so (3 million miles) and completing one trip around its sun in just 1.5 days. Atmospheric temperatures soar to more than 4,000 degrees C (7,200 degrees F), making it the hottest exoplanet yet discovered.

At those temperatures, elements are almost completely vaporised. The atmosphere is cloudless and free of aerosols, giving the planet a clear sky that is flooded by light from the star.

A team of scientists with the Universities of Bern and Geneva used the HARPS-North spectrograph on the Italian National Telescope at La Palma to study the spectra of elements in KELT-9b’s atmosphere, finding iron and titanium atoms. Follow-up observations confirmed the initial detections and found signs of vaporised sodium, magnesium, chromium and the rare-Earth metals scandium and yttrium.

“Our team predicted that the spectrum of this planet could well be a treasure trove where a multitude of species can be detected that have not been observed in the atmosphere of any other planet before,” said Jens Hoeijmakers, lead author of the study published in the journal Astronomy & Astrophysics.

“With further observations, many more elements may well be discovered by using the same technique in the atmosphere of this planet in the future, and perhaps also on other planets that are heated to similarly high temperatures.”

Kevin Heng, director of the Center for Space and Habitability at the University of Bern, said the spectrographic techniques used to identify constituents in KELT-9b’s atmosphere may one day lead to even more profound results.

“The chances are good that one day we will find so-called biosignatures, i.e. signs of life, on an exoplanet, using the same techniques that we are applying today,” he said. “Ultimately, we want to use our research to fathom the origin and development of the solar system as well as the origin of life.” </s> Illustration: NASA/JPL-Caltech

Scientists directly observed the signal of iron and titanium atoms in the atmosphere of an exoplanet 600 light-years from Earth, a new paper reports.



KELT-9b is a planet entirely alien to our own Solar System—it’s 2.88 times the mass of Jupiter, with a year lasting just 1.5 Earth days and temperatures over 4,000 Kelvin (6,740 Fahrenheit). It’s the hottest known exoplanet, and the site of the first exoplanetary observation of iron and titanium atoms. It’s a stepping stone that will help astronomers one day characterize the atmospheres of more hospitable planets.

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“It’s hard to distinguish an exoplanet like Venus from an exoplanet like Earth,” study author Jens Hoeijmakers from the University of Geneva in Switzerland told Gizmodo. “We need to recognize the chemistry in the atmospheres of exoplanets. KELT-9b is an easy target, an easy system to understand. My philosophy is if you cannot do the easy cases, then you cannot do the hard cases either.”

The data came from a July 31, 2017 observation made by the Telescopio Nazionale Galileo on the Spanish Canary Island of La Palma. The telescope recorded the planet passing in front the blazingly hot blue giant KELT-9 star, essentially acting as a light filter, tweaking the colors of the starlight. Subtracting the light collected from just the star from the light collected when the planet passed in front of the star revealed the spectral lines of titanium and iron. The researchers also detected a slight shift to the spectral wavelengths: the Doppler effect signature of the planet moving through space. This confirmed that the spectral lines didn’t come from the star or dust in the intervening space, according to the paper published in Nature.

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Astronomers from the University of Bern, the University of Geneva, and others contributed to the discovery. The Bern researchers, without showing this data to Hoeijmakers, asked him to independently simulate KELT-9b to see if it would have visible iron. His simulations found that, yes, the planet should have iron visible to an observer. This bolstered their confidence that they had truly observed iron and titanium on the exoplanet.

Illustration: Denis Bajram

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While iron is abundant here on Earth, it’s a difficult element to measure on exoplanets due to its optical properties. As far as Hoeijmakers and other sources we spoke to could tell, this was the first direct detection of an iron or titanium atom on an exoplanet, though other results have hinted at the presence of these elements.



This discovery helps scientists determine the nature of the planet and how it formed. More generally, it serves as an important advance on the journey to fully characterizing exoplanet atmospheres.

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“The Hoeijmakers paper is a great first step in identifying the chemical ingredients of the atmosphere,” Laura Kreidberg from the Harvard-Smithsonian Center for Astrophysics told Gizmodo. It “opens the door to many more investigations—searching for additional chemical species and observing different regions of the planet’s atmosphere.”

Fully understanding an exoplanet’s atmosphere could ultimately help scientists tell the difference between an Earth-like or a Venus-like planet—a crucial distinction if you’re hunting for life. The goal is to find biosignatures, molecular spectra indicating that a planet’s atmosphere has been altered by some life form.

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Others were interested in the planet by itself. “It’s so strongly irradiated that it’s hotter than most stars,” Drake Deming, astronomy professor at the University of Maryland who reviewed the paper, told Gizmodo. He noted that the most common stars in the galaxy aren’t like the Sun, but are cooler, dim M-dwarfs, as opposed to our sun, a hotter G-type main sequence star (sometimes called a yellow dwarf).



Hoeijmakers noted that the paper was the result of an intense amount of collaboration between researchers, and felt it was a model of how science should be done. He said: “Every single person on the author list made a crucial contribution to this story.”



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And there will be plenty more opportunities to collaborate. Scientists will soon have many more observations to analyze, both from the telescope at La Palma and other future telescopes.

[Nature] </s> For the first time ever, astronomers have found iron and titanium in the atmosphere of a planet outside the solar system. The exoplanet, named KELT-9b, is the hottest alien world ever discovered. The planet is so scorching, it's even hotter than most stars.

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). [Gallery: The Strangest Alien Planets]

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 spotted in an exoplanet's atmosphere before — but not in its atomic form. In September 2017, astronomers using the Hubble Space Telescope announced that they had found titanium dioxide (molecules consisting of one titanium atom and two oxygen atoms) in the atmosphere of an exoplanet named Kepler-13A.

Astronomers can detect different elements by looking at the spectrum of light coming from an object in space. Because the exoplanet doesn't emit its own light, Heng and his team of researchers looked at telescope data collected during a solar transit, when the exoplanet passed directly in front of its star as seen from Earth.

Conveniently, the data already existed before Heng and his co-authors decided to tackle this study. After his colleagues at the University of Geneva used that spectral data to look for hydrogen in KELT-9b's atmosphere, "they actually kept the data in the drawer because there was no reason to search for iron or titanium," Heng said. "Then, a few months ago, we did a theoretical study, which predicted that iron and titanium would be there, and that motivated the search."

Using the year-old data from the Galileo National Telescope in La Palma, Spain, the researchers started hunting for metals in the spectrum of light that shone through KELT-9b's atmosphere over a 4-hour-long transit. This data was collected using a spectrograph instrument called HARPS, the High Accuracy Radial Velocity Planet Searcher.

"Different atoms or molecules have a fingerprint when you split the light into a spectrum," Heng said. "Given enough resolution, given good enough data, every molecule has a unique fingerprint." Finding the fingerprints of iron and titanium — elements that Heng and his team already suspected would exist in KELT-9b's atmosphere — would require "a combination of high-performance computing know-how, a careful curation of the spectroscopic databases and meticulous attention to detail," Heng wrote in a blog post on Nature.com.

Heng's team sought the help of Simon Grimm, an astrophysicist at the University of Bern "who is (among other things) an expert in the computation of the opacities of atoms and molecules," Heng wrote in the blog post. "These opacities are not trivial to compute, because one needs to evaluate the strengths and shapes of millions to billions of spectral lines."

Previous studies that looked at hydrogen in the atmosphere of KELT-9b were able to see a strong hydrogen absorption line in the spectrum without doing a more complicated cross-correlation analysis like Heng and his team had to do to find iron and titanium. Astronomers who collected data to look for hydrogen "lacked the theoretical motivation to conduct a serious search for metals such as iron," Heng wrote.

Another study, published July 2 in the journal Nature Astronomy, showed that hydrogen is actually "boiling off" from the atmosphere of KELT-9b and being sucked into the planet's parent star. "It is possible that heavy metal elements are also escaping because the dramatic hydrogen escape can 'drag' heavy elements to very high [in the] atmosphere," Fei Yan, an astronomer at the Max Planck Institute for Astronomy and the lead author of the study, told Space.com in an email.

While the iron and titanium in KELT-9b's atmosphere was a huge discovery, Heng told Space.com that "the technique itself is really exciting" as well. "This is the same technique that we will use to detect signatures of biology, or biosignatures," Heng said. "On Earth, we think it's oxygen and a few other obscure molecules, but we don't know what biosignatures are in general. If you knew what they were … you could use exactly the same technique to detect these molecules in cooler, smaller planets."

For the first time ever, astronomers have found iron and titanium in the atmosphere of a planet outside the solar system. The exoplanet, named KELT-9b, is the hottest alien world ever discovered. The planet is so scorching, it's even hotter than most stars.

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). [Gallery: The Strangest Alien Planets]

An artist's impression of the exoplanet KELT-9b, which orbits so close to its host star that the star's disk appears 70 times larger than our sun in the sky.

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 spotted in an exoplanet's atmosphere before — but not in its atomic form. In September 2017, astronomers using the Hubble Space Telescope announced that they had found titanium dioxide (molecules consisting of one titanium atom and two oxygen atoms) in the atmosphere of an exoplanet named Kepler-13A.

Astronomers can detect different elements by looking at the spectrum of light coming from an object in space. Because the exoplanet doesn't emit its own light, Heng and his team of researchers looked at telescope data collected during a solar transit, when the exoplanet passed directly in front of its star as seen from Earth.

Conveniently, the data already existed before Heng and his co-authors decided to tackle this study. After his colleagues at the University of Geneva used that spectral data to look for hydrogen in KELT-9b's atmosphere, "they actually kept the data in the drawer because there was no reason to search for iron or titanium," Heng said. "Then, a few months ago, we did a theoretical study, which predicted that iron and titanium would be there, and that motivated the search."

Using the year-old data from the Galileo National Telescope in La Palma, Spain, the researchers started hunting for metals in the spectrum of light that shone through KELT-9b's atmosphere over a 4-hour-long transit. This data was collected using a spectrograph instrument called HARPS, the High Accuracy Radial Velocity Planet Searcher.

"Different atoms or molecules have a fingerprint when you split the light into a spectrum," Heng said. "Given enough resolution, given good enough data, every molecule has a unique fingerprint." Finding the fingerprints of iron and titanium — elements that Heng and his team already suspected would exist in KELT-9b's atmosphere — would require "a combination of high-performance computing know-how, a careful curation of the spectroscopic databases and meticulous attention to detail," Heng wrote in a blog post on Nature.com.

Heng's team sought the help of Simon Grimm, an astrophysicist at the University of Bern "who is (among other things) an expert in the computation of the opacities of atoms and molecules," Heng wrote in the blog post. "These opacities are not trivial to compute, because one needs to evaluate the strengths and shapes of millions to billions of spectral lines."

Previous studies that looked at hydrogen in the atmosphere of KELT-9b were able to see a strong hydrogen absorption line in the spectrum without doing a more complicated cross-correlation analysis like Heng and his team had to do to find iron and titanium. Astronomers who collected data to look for hydrogen "lacked the theoretical motivation to conduct a serious search for metals such as iron," Heng wrote.

Another study, published July 2 in the journal Nature Astronomy, showed that hydrogen is actually "boiling off" from the atmosphere of KELT-9b and being sucked into the planet's parent star. "It is possible that heavy metal elements are also escaping because the dramatic hydrogen escape can 'drag' heavy elements to very high [in the] atmosphere," Fei Yan, an astronomer at the Max Planck Institute for Astronomy and the lead author of the study, told Space.com in an email.

While the iron and titanium in KELT-9b's atmosphere was a huge discovery, Heng told Space.com that "the technique itself is really exciting" as well. "This is the same technique that we will use to detect signatures of biology, or biosignatures," Heng said. "On Earth, we think it's oxygen and a few other obscure molecules, but we don't know what biosignatures are in general. If you knew what they were … you could use exactly the same technique to detect these molecules in cooler, smaller planets."

It is unlikely that astronomers will find any signs of life on this hellish planet, but Heng and his team have found some other interesting elements in the spectra from KELT-9b. "I don't want to reveal too much, but we have found other metals," he said. "We are also trying to get Hubble Space Telescope time to search for water as well." The goal is to eventually have "a complete chemical inventory of the planet," he said. Hubble will also be able to provide some insight into the weather on KELT-9b. "There should be violent storms on this planet," he said.

The research was published today (Aug. 15) in the journal Nature. </s> This is the first time ever than astronomers find iron and titanium in the atmosphere of an exoplanet.

The name of “ultrahot Jupiter” speaks for itself. This newly discovered class of gas giants are the hottest planets ever detected. In fact, they’re hot enough to be stars and have sizzling surface temperatures exceeding 3,100 degrees Fahrenheit (1,700 degrees Celsius), notes Space.com.

The hottest of them all is a scorching place called KELT-9b, a gas giant three times more massive than Jupiter and twice as wide. Discovered last year with the help of the Kilodegree Extremely Little Telescope (KELT) at Winer Observatory in southeastern Arizona, KELT-9b has staggering surface temperatures of up to 7,800 degrees Fahrenheit (4,300 Celsius) on its day side (ultrahot Jupiters are tidally locked, with one side perpetually facing their parent star), Space.com reported at the time of its discovery.

That’s hotter than many of the dwarf stars dotting the Milky Way and just 2,200 degrees Fahrenheit (1,200 degrees Celsius) cooler than the surface of the sun, which makes KELT-9b the hottest alien world ever discovered, explains the University of Geneva (UNIGE) in Switzerland.

Although ultrahot Jupiters are too hot to be habitable, these sweltering gas giants are utterly fascinating nonetheless, shows New Atlas, particularly when it comes to their atmospheric properties.

As the Inquisitr previously reported, these planets are hot enough for water molecules to disintegrate on their day side and recombine on their night side. And, as it turns out, KELT-9b is so fiery, it even vaporized heavy metals.

According to a new study, published yesterday in the journal Nature, astronomers have found iron and titanium vapors in KELT-9b’s atmosphere.

This incredible discovery marks the first time that these heavy metals have ever been detected in the atmosphere of an exoplanet. Everything started with a theoretical study of the air around KELT-9b, conducted by UNIGE scientists in collaboration with researchers from the University of Bern (UNIBE), also in Switzerland.

“This planet is a unique laboratory to analyze how atmospheres can evolve under intense stellar radiation,” said David Ehrenreich, principal investigator with the UNIGE team.

Curious to see what they would find in the atmosphere of the hottest known planet, the combined team ran simulations that predicted the air around KELT-9b would contain iron vapor.

“The results of these simulations show that most of the molecules found there should be in atomic form, because the bonds that hold them together are broken by collisions between particles that occur at these extremely high temperatures,” said Kevin Heng, study co-author and a UNIBE professor.

Intrigued by what they had found, the scientists analyzed the planet’s spectrum with the HARPS-North spectrograph on the Galileo National Telescope in Spain and uncovered the fingerprint of iron vapor really does exist in KELT-9b’s atmosphere.

But that’s not all they found, notes UNIGE. In addition to iron, HARPS-North also picked up the signature of titanium vapor — a first in exoplanet discoveries.

“With the theoretical predictions in hand, it was like following a treasure map,” explained study lead author Jens Hoeijmakers, affiliated with both UNIGE and UNIBE. “And when we dug deeper into the data, we found even more.”

So, what has created the astounding conditions that make all this possible? Well, first of all, the gas giant orbits a blistering star almost twice as hot as the sun. Dubbed KELT-9, this flaming star lies 650 light-years from Earth in the Cygnus constellation (the Swan) and has a surface temperature of more than 18,032 degrees Fahrenheit (10,000 degrees Celsius).

Secondly, the planet circles its star in a very tight orbit and sits 30 times closer to KELT-9 than Earth to the sun. This proximity makes KELT-9b complete a full orbit in just 36 hours and become heated to extreme temperatures.

“The nearby warm blue star covers 35 degrees in the planet’s sky, about 70 times the apparent size of the sun in the Earth’s sky. Under this scorching sun, the planet’s atmosphere is warm enough to shine in reddish-orange tones and vaporize heavy metals such as iron and titanium,” reveals UNIGE in a news release. </s> Artist's view of a sunset over KELT-9b. The nearby warm blue star covers 35° in the planet's sky, about 70 times the apparent size of the sun in the Earth's sky. Under this scorching sun, the planet's atmosphere is warm enough to shine in reddish-orange tones and vaporize heavy metals such as iron and titanium. Credit: Denis Bajram Exoplanets, planets in other solar systems, can orbit very close to their host stars. When the host star is much hotter than the sun, the exoplanet becomes as hot as a star. The hottest "ultra-hot" planet was discovered last year by American astronomers. Today, an international team led by researchers from the University of Geneva (UNIGE), who collaborated with theoreticians from the University of Bern (UNIBE), Switzerland, discovered the presence of iron and titanium vapours in the atmosphere of this planet. The detection of these heavy metals was made possible by the surface temperature of the planet, which reaches more than 4000 degrees. This discovery is published in the journal Nature.

KELT-9 is a star located 650 light years from Earth in the constellation Cygnus (the Swan). With a temperature of over 10,000 degrees, it is almost twice as hot as the sun. This star is orbited by a giant gas planet KELT-9b, which is 30 times closer than the Earth's distance from the sun. Because of this proximity, the planet circles its star in 36 hours and is heated to a temperature of over 4,000 degrees. It's not as hot as the sun, but hotter than many stars. At present, we do not yet know what such a planetary atmosphere looks like, or how it can evolve under such conditions.

The NCCR PlanetS researchers performed a theoretical study on the atmosphere of the planet KELT-9b. "The results of these simulations show that most of the molecules found there should be in atomic form, because the bonds that hold them together are broken by collisions between particles that occur at these extremely high temperatures," explains Kevin Heng, professor at the UNIBE. This is a direct consequence of the extreme temperature. Their study also predicts that it should be possible to observe gaseous atomic iron in the planet's atmosphere using current telescopes.

Light reveals the chemical components of the atmosphere

The research team had observed this planet precisely as it was moving in front of its host star (i.e. during a transit). During transit, a tiny fraction of the light from the star filters through the planet's atmosphere, and analysis of this filtered light can reveal the chemical composition of the atmosphere. This is achieved with a spectrograph, which separates white light into its component spectrum. Iron vapour, if present, would leave a recognisable fingerprint in the spectrum of the planet.

Using the HARPS-North spectrograph, built in Geneva and installed on the Telescopio Nazionale Galileo in La Palma, astronomers discovered a strong signal corresponding to iron vapour in the planet's spectrum. "With the theoretical predictions in hand, it was like following a treasure map," says Jens Hoeijmakers, a researcher at the Universities of Geneva and Bern and lead author of the study. "And when we dug deeper into the data, we found even more," he adds. The team also detected the signature of titanium in vapour form.

This discovery reveals the atmospheric properties of a new class of so-called "ultra-hot Jupiter." However, scientists believe that many exoplanets have completely evaporated in environments similar to KELT-9b. Although this planet is probably massive enough to withstand total evaporation, this new study demonstrates the strong impact of stellar radiation on the composition of the atmosphere. Indeed, these observations confirm that the high temperatures on this planet break apart most molecules, including those containing iron or titanium. In cooler giant exoplanets, these atomic species are thought to be hidden within gaseous oxides or in the form of dust particles, making them hard to detect. This is not the case on KELT-9b. "This planet is a unique laboratory to analyze how atmospheres can evolve under intense stellar radiation," concludes David Ehrenreich, principal investigator with the UNIGE's FOUR ACES team.

Explore further: Hunting molecules to find new planets

More information: H. Jens Hoeijmakers et al, Atomic iron and titanium in the atmosphere of the exoplanet KELT-9b, Nature (2018). DOI: 10.1038/s41586-018-0401-y </s> Astronomers have identified thousands of exoplanets with the aid of instruments like the Kepler Space Telescope, but we don’t know much about most of those worlds. From a great distance, Earth and Venus would appear to be very similar, but of course, we know that Earth is quite habitable and Venus has clouds of sulfuric acid. Scientists have taken a step toward better understanding the environment of exoplanets by studying a gas giant called KELT-9b. For the first time, scientists have detected iron and titanium on an exoplanet.

While Earth and Venus may look similar, there’s no mistaking KELT-9b for an Earth-like planet. It’s 2.88 times the mass of Jupiter and orbits the blue giant star KELT-9 every 1.5 Earth days. It also has a surface temperature of 6,740 degrees Fahrenheit (3,626 degrees Celsius). That means it’s probably hot enough to tear water molecules apart.

Astronomers turned the Telescopio Nazionale Galileo in the Canary Islands toward KELT-9b last summer, observing as the planet transited in front of KELT-9. They collected the spectra of light shining through KELT-9b’s atmosphere and then subtracted the signature of light collected just from the star. That left spectral lines of titanium and iron. The team even simulated the atmosphere of KELT-9b without using this data to confirm that it should have visible iron.

This marks the first time either element has been detected on an exoplanet. To make sure the readings were not from the star itself, the team identified a Doppler shift in the signal, indicating it came from the planet as it moved through space.

It’s impossible with current technology to detect iron or titanium on Earth-like exoplanets because it’s not a component of the atmosphere. A gas giant like KELT-9b is a very different story. This research gets us closer to proper characterization of exoplanets, which is essential to understanding whether they could support life. A gas giant couldn’t support life as we know it, but understanding the atmosphere of Jupiter-like planets can help us make educated guesses about the composition of other planets in the same solar system.

Future projects like the James Webb Telescope will allow scientists to observe exoplanets in more detail than ever before. Meanwhile, NASA’s TESS mission is scouring the sky in search of new exoplanets to analyze. This study provides a roadmap to survey the atmospheres of such planets, which could help unlock new areas of research.

Now read: Mysterious ‘Rogue Planet’ Roams the Stars Alone, Not So Far From Earth, NASA’s TESS Spacecraft Captured Amazing Footage of a Comet During Testing, and Exoplanet Just 11 Light Years Away Could Support Life </s> If planets come any hotter than KELT-9b we're yet to find them. Not only does this roasted ball of gas win first prize for scorching temperatures, it can now claim to be the first planet known to have free-roaming atoms of iron and titanium in its atmosphere.

To most of us, the discovery is just one more extreme place we'll never visit in our galaxy. For astronomers keen on coming up with better ways to study planets outside our Solar System, the find could have some useful applications.

A team of researchers from across Europe used data from the High Accuracy Radial velocity Planet Searcher for the Northern hemisphere (HARPS-N) spectrograph in the Canary Islands to pick out elements in the planet's atmosphere.

Astronomers first published data on KELT-9b's temperature last year, estimating it to be up around 4,600° Kelvin (about 4,300° Celsius, or 7,800° Fahrenheit).

By comparison, our own Sun's surface is just under 6,000° Celsius, or around 10,000° Fahrenheit. So we're talking a spicy space meatball.

KELT-9b's unusual heat comes courtesy of a rather intimate relationship with its parent star, HD 195689 (or KELT-9 for short) – a star with a little over twice the mass of our Sun roughly 620 lightyears away.

There's no easy way to tell exactly how close the two objects are, but KELT-9b, which is roughly double the size of Jupiter, can complete a lap in just under 36 hours, so the distance can't be huge.

Initial observations have suggested the exoplanet has an atmosphere made up mostly of hydrogen. But to really get a sense of the planet's character, it's important to detect fingerprints of other elements.

With such a high average temperature, researchers theorised that common transitory metals such as iron could appear in the atmosphere as both charged and free-roaming atoms.

Temperatures that vaporise metals aren't unknown among exoplanets. The 'hot Jupiter' WASP-12b is thought to have a surface temperature of roughly 2,000° Celsius (about 3,600° Fahrenheit), boiling aluminium and titanium into clouds.

But KELT-9b has that beat, being hot enough to prevent condensates from forming - which means it could have cloud-free skies dusted with metallic vapour.

The research team used emission spectroscopy to look for signs of iron and titanium in recordings made of KELT-9b with HARPS-N last year, and have now reported that the planet's atmosphere contains both in ionic and neutral forms.

While we can be fairly certain the elements are present, their exact proportions remain a mystery. Analysis requires a set of standards to take into account the effect of our own atmosphere on the spectrum, something we still don't have.

Fortunately discoveries like this one are just what we need to develop better tools for interpreting the spectral emissions from exoplanets.

Right now researchers are forced to rely on certain assumptions about the mixes of materials making up distant planets. That's not necessarily a bad thing, but comes at a cost of precision.

Fixing the proportions of key elements will lead to better methods for classifying distant worlds and pulling apart their ingredient lists in detail.

And that's the best we have right now; even if we do manage to send probes out to nearby stars, our ability to get up close and personal with a multitude of distant worlds any time soon is pretty much zip.

So if we want to study the ever-growing list of planets we're discovering, we're limited to pulling as much detail as we can from the faint glow of light spilling from their surfaces.

We might not ever want to go to KELT-9b. But its iron skies are just the ticket we need to access knowledge about the rest of the Universe.

This research was published in Nature. </s> Fingerprints of metals and possible traces of water found in low-density exoplanet. Pictured, an artist's conception depicting the Kepler-10 star system, located about 560 light-years away near the Cygnus and Lyra constellations.

An international team of astronomers detected "fingerprints" of metals in the atmosphere of an exoplanet for the first time as well as possible signs of water, a find that could bolster the search for life beyond Earth.

Sitting 332 light years away from Earth, WASP-127b is one of the least dense gas giant exoplanets ever discovered, a feature which makes it unique among thousands of extra-solar worlds cataloged to date. Though it’s nearly one and a half times bigger than Jupiter, our Solar System’s largest planet, the mass of the alien world is not even half of what Jupiter has on offer.

More importantly, the exoplanet takes a little over four days to complete a single orbit of its host star and is heated to temperatures of up to 1,127 degrees Celsius (2060.6 degrees Fahrenheit). The characteristic makes this world one hell of a place to live, but, despite knowing this since the planet’s discovery in 2016, a team of researchers from the University of Cambridge and the Instituto de Astrofísica de Canarias (IAC) used it as a subject of study while using the Gran Telescopio Canarias, a reflecting telescope in Spain.

The team observed the atmospheric composition of the exoplanet and detected fingerprints signaling a high concentration of alkali metals, mainly sodium, potassium, and lithium. The discovery, a first on an exoplanet, and some modeling work also helped the team determine that the skies of the planet are partly clear.

“The detection of a trace element such as lithium in a planetary atmosphere is a major breakthrough and motivates new follow-up observations and detailed theoretical modeling to corroborate the findings,” study co-author Nikku Madhusudhan said in a statement. The team believes the discovery of lithium could provide critical insight into the formation of the planet and the evolution of the WASP-127 system. Even the star of the planet, WASP-127, is rich in lithium, which suggests it could be a red giant, thousands of times bigger than the Sun, or a supernova.

“The particular characteristics of this planet allowed us to perform a detailed study of its rich atmospheric composition,” study’s first author Guo Chen said in the statement.

But that’s not it. Along with traces of metal in the atmosphere, the team also found possible signs of water, which, if confirmed, could mean a major breakthrough in the field of astronomy. “While this detection is not statistically significant, as water features are weak in the visible range, our data indicate that additional observations in the near-infrared should be able to detect it,” co-author Enric Pallé said of the possible discovery of water.

The team adds that further observations from James Webb Space Telescope, NASA’s successor to the Hubble, should be able to take a close look at the atmosphere of WASP-127b and reveal more about the low-density gas giant and its characteristics.

The study titled, “The GTC exoplanet transit spectroscopy survey IX. Detection of Haze, Na, K, and Li in the super-Neptune WASP-127b,” will be published in the journal Astronomy and Astrophysics and an arXiv preprint is available online.
Rare-earth metals are discovered in KELT-9b, an exoplanet located 650 light-years away from Earth.