Exoplanet WASP-104b is one of the least-reflective planets ever discovered. First identified in 2014 according to the Open Exoplanet Catalogue, WASP-104b belongs to a class of “exotic worlds” known as “hot Jupiters.”

These are gaseous exoplanets the size of Jupiter, only considerably much hotter because of their close proximity to their parent stars, which they orbit in less than 10 days, NASA explains.

Initially “considered oddballs,” hot Jupiters turned out to be quite common. Yet, although we’re used to them by know, they remain “shrouded in mystery,” NASA points out.

One thing we do know about hot Jupiters is that most of them are tidally locked — one side of the planet always faces its parent star, making it the permanent day side — and that they’re relatively dark, absorbing about 60 percent of the starlight that reaches them, notes Science Alert.

Last year, hot Jupiter WASP-12b made headlines when astronomers found out that it absorbs at least 94 percent of the light. At the time, this exoplanet was called “spooky” and “weird” and was described as “pitch black.”

But WASP-104b really takes the cake on this one. A new research by Keele University in the U.K. revealed that WASP-104b absorbs more than 97 to 99 percent of light.

Pause for gasp.

The research, a six-page paper published in the Cornell University Library, describes the exoplanet as being “darker than coal” (seriously, that’s what they put in the title) and deems it “one of the least-reflective planets found to date.”

Hot Jupiter WASP-104b is Darker Than Charcoal: WASP-104b, a so-called Hot Jupiter, has been identified in a new research as one of the least-reflective planets found to date. Astronomers classify a planet as a "Hot Jupiter" that are gas giant... https://t.co/k0ceVoVl1y — Rumor About (@rumorabout) April 23, 2018

“From all the dark planets I could find in the literature, this is top five-ish. I think top three,” lead researcher and astrophysicist Teo Mocnik said in a statement.

The authors analyzed data from NASA’s Kepler Space Telescope K2 mission, specifically the short-cadence data from Campaign 14, and found out that WASP-104b is surrounded by a thick, hazy atmosphere made up of atomic sodium and potassium. These elements absorb light in the visible spectrum, making the planet very dark on the day side (the only side that sees any starlight).

Since the planet is extremely close to its host star, WASP-104b is too hot for clouds to form in its atmosphere (on the day side, that it), which means there’s almost nothing there to reflect the light.

In fact, the exoplanet orbits its parent star — a yellow dwarf located about 466 light-years away from Earth, in the Leo constellation, Science Alert reports — from a distance of only 2.6 million miles. Remarkably, this peculiar planet completes a full orbit in just 1.75 days.

The only hot Jupiter that’s darker than WASP-104b is an exoplanet dubbed TrES-2b, which only reflects 0.1 percent of the light from its parent star, notes Science Alert.

A study has been revealed that WASP-104b, a Hot Jupiter exoplanet, has been discovered as one of the darkest exoplanets ever seen. https://t.co/APuAP36iRm — the Context (@thecontextnet) April 21, 2018

The media outlet clarifies, however, that these planets are not actually dark in color. In fact, judging by their extreme heat, they more likely glow in “a deep, bruise-like purple or a dull molten red” hue, Science Alert points out.

But WASP-104b is not the only hot Jupiter with an impressive tale to tell. In December, the world was acquainted with “death planet” WASP-18b, the first hot Jupiter with no water and an upper atmosphere almost completely made up of carbon monoxide.

Equally baffling is the hot Jupiter known as Kepler-13ab, a planet where the atmosphere “snows” titanium dioxide, the active ingredient used in most brands of sunscreen. </s> WASP-104b, a so-called Hot Jupiter, has been identified in a new research as one of the least-reflective planets found to date. Astronomers classify a planet as a "Hot Jupiter" that are gas giant exoplanets, physically similar to Jupiter but that has a very short orbital period with less than 10 days. The close proximity to their stars and high surface-atmosphere temperatures resulted in the moniker "hot Jupiters."

Researchers a the Keele University in the UK found the unique characteristic of WASP-104b by analyzing Kepler's K2 short-cadence data from Campaign 14. The exoplanet's close proximity to its star, a yellow dwarf, is likely the reason for the darkness.

Most hot Jupiters including the WASP-104b are tidally locked. One side of the planet always faces its star, making it the permanent day side. In the case of WASP-104b, the distance is only 2.6 million miles from the star and it only needs 1.75 days for a full orbit, according to ScienceAlert. Lead researcher Teo Mocnik talked to New Scientist about discovery (paywall).

The WASP-104b exoplanet was discovered back in 2014, along with the WASP-106b.

The detailed research can be found in the paper titled "WASP-104b is Darker than Charcoal" authored by T. Močnik, C. Hellier, J. Southworth and published in the Cornell University Library under arXiv:1804.05334. </s> The darkest planets may be black as charcoal Duc Tri Nguyen / Alamy Stock Photo

Astronomers have discovered one of the darkest planets ever seen. It’s so dark, they’re comparing it to charcoal.

WASP-104b is a fast gas giant. It is a Jupiter-mass planet that orbits its star once every 1.75 days. The planet circles close to its star, so it receives enough radiation that its clouds are swept away, letting the potassium and sodium come out to play. Those elements – found in the haze layer – absorb more than 97 to 99 per cent of the … </s> Share this article with Google Plus

Scientists may have found a planet so dark and evil-looking it might be among the most heavy metal places in the known universe.

The planet is believed to be one of the darkest ever found: so completely black that it absorbs up to 99% of the light that hits it.

As they say in Spinal Tap: ‘None more black’.

Researchers have compared it to charcoal, and it’s a pretty horrendous place, no matter how ‘metal’ you are.

The planet is named Wasp-104b, and is a ‘hot Jupiter’, a gas giant as big as Jupiter in our solar system, but much, much closer to the star, ScienceAlert reports.

Most hot Jupiters are dark (and extremely, extremely hot) – but this one is far, far darker than expected.

Researchers at Keele University say that Wasp-104B is much darker, absorbing 97 to 99% of light.

Lead author Teo Mocnik said, ‘From all the dark planets I could find in the literature, this is top five-ish. I think top three.’

The reason it’s so dark is probably down to how close it is to its planet, a yellow dwarf in the constellation Leo.

It takes just 1.75 days to do a full orbit, being just 2.6 million miles from the star – and its thick hazy atmosphere may contain atomic sodium and potassium, which absorb light. </s> A new pitch-black planet that absorbs 99% of all light could be among the darkest celestial bodies ever uncovered, scientists say.

Particles found in the dense atmosphere of Wasp-104b, a planet dubbed a 'hot Jupiter' for its similarities to the gas giant, absorb almost all light.

The planet it so close to its host star that the reflective clouds that most planets have are burnt off.

As a result, it is left with a hazy layer thick with potassium and sodium atoms that absorb all light in the visible spectrum.

This means it appears as a dark lump - probably purple or molten red - very faintly glowing like an ember in a firepit.

Experts found the strange object thanks to the shadow it casts against its host, a yellow dwarf around 466 light-years away in the constellation Leo.

Researchers were able to track this 'transit' across the star's surface, which takes place once every 1.75 days.

The findings were made by researchers at Keele University, who used data from Nasa's Kepler space telescope to make the discovery.

'Hot Jupiters' are giant gas exoplanets that are physically similar to Jupiter but have a short orbital period of less than ten days.

Wasp-104b falls within a sub category of 'hot Jupiter' planets that appear to reflect virtually no light - more than 97 to 99 per cent in the case of this planet.

It is not known which is the darkest of all the planets as the difference comes down to a fraction of a per cent or even the margin of error in scientist's calculations, researchers say.

'From all the dark planets I could find in the literature, this is top five-ish,' lead researcher and astrophysicist Teo Mocnik told New Scientist. 'I think top three.'

Wasp-104b was first discovered in 2014 as part of the Wide Angle Search for Planets project that gives it its name.

Researchers at the time noted its fast orbit around its host star which is believed to lead to its unique ability to absorb light.

As with other 'hot Jupiters', the time it takes Wasp-104b to rotate on its axis matches the time it takes to orbit its host star - a characteristic called tidal locking that also affects our Moon.

This means that one side always faces its host star, and is constantly in daytime, and the other faces away in a permanent night.

As Wasp-104b circles so close to its star - around 2.6 million miles (4.3 million km), a fraction of Mercury's 36 million mile (58 million km) orbit around the sun - any reflective clouds that could form are swept away by its radiation.

This gives free reign for potassium and sodium particles to encircle the planet, giving its a thick, hazy atmosphere which absorbs light on its day side.

Planets in our own solar system have a wide range of properties, but they are distinguished by two: their size and their orbit. Their size determines if the planet can have a life-sustaining atmosphere, while the orbit affects the surface temperature and whether there could be liquid water on its surface. A habitable planet, one that could have liquid water on its surface, must be between about 80 to 200 per cent the diameter of Earth. Planets that are smaller than 8/10ths of an Earth diameter have less than half its mass. As a result, they do not have enough gravity to hold onto a life-sustaining atmosphere. Planets that are more than twice the diameter of Earth have about ten Earth masses and enough gravity to hold onto hydrogen, the most abundant element in the Universe. Such large planets turn into gas giants like Jupiter and Saturn. Jupiter is more than ten times the diameter of Earth and more than 300 times the mass of Earth. Most of the 300 plus planets that have been detected so far are gas giants. The first extra-solar planet detected around a star similar to the sun was 51 Peg. It has about the mass of Jupiter. Unlike Jupiter, which is five times as far from the sun as Earth and orbits the sun in 12 years, 51 Peg is twenty times closer to its star than Earth is to the sun and orbits its star every four days. Planets like these are referred to as 'Hot Jupiters'.

Clouds may form on the night side, but this receives no light from the host star which they could reflect.

In terms of its appearance, scientists say Wasp-104b's description as appearing darker than charcoal may be misleading.

Adam Burrows of Princeton University, who co-authored a paper in 2000 predicting these ultra-dark planets, told New Scientist: 'It’s probably going to be purple.'

The full findings of the study were published on the pre-print repository arXiv, and are awaiting peer review. </s> Out in the cold, dark cosmos, a team of astronomers has discovered an exoplanet that is completely cloud-free.

The Kepler Space Telescope has contributed a great deal to astronomy, revealing thousands of strange exoplanets against the backdrop of the blackness of space.

And, sometimes, it helps astronomers find a particular planet that, to those of us on Earth, sounds truly alien.

The latest one to join that list is a ‘hot Saturn’ dubbed WASP-96b, analysed in detail by a team of international astronomers led by Dr Nikolay Nikolov from the University of Exeter and including Dr Ernst de Mooij from Dublin City University’s School of Physical Sciences.

Publishing their findings to Nature, the team revealed that a unique set of circumstances mean that WASP-96b has an atmosphere completely free of clouds.

Using the European Southern Observatory’s Very Large Telescope in Chile, the team studied the atmosphere of WASP-96b when the planet passed in front of its host star. This allowed them to measure the decrease of starlight caused by the planet and its atmosphere, thereby determining the planet’s atmospheric composition.

In the same way that a person’s fingerprints can reveal their identity, atoms and molecules can be identified through spectral analysis. In the case of WASP-96b, the results showed sodium.

This was important in determining the planet’s chemical composition because sodium can only be detected on a cloud-free planet.

WASP-96b has a sweltering average temperature of more than 1,000C and a mass similar to Saturn, but it is about 20pc larger than Jupiter.

It was the only planet out of 20 analysed during the study to show a cloud-free atmosphere.

“Until now, sodium was revealed either as a very narrow peak or found to be completely missing,” Nikolov said.

“This is because the characteristic ‘tent-shaped’ profile can only be produced deep in the atmosphere of the planet and for most [planets] clouds appear to get in the way.”

Speaking of its importance to our understanding of similar planets, de Mooij of DCU said: “WASP-96b will also provide us with a unique opportunity to determine the abundances of other molecules such as water, carbon monoxide and carbon dioxide with future observations.” </s> For the first time ever, astronomers detected sodium atoms in the atmosphere of an exoplanet, which suggests it is cloud-free.

“Hot Jupiters” aren’t the only eccentric exoplanets out there. It turns out that “hot Saturns” can be quite whimsical too. For instance, “hot Saturn” WASP-96b seems to be “entirely cloud-free,” says astronomer Nikolay Nikolov, lead author of a recent study on the atmosphere of this peculiar exoplanet.

This strange gas giant (the planet, that is) lies 980 light-years away in the Phoenix constellation. Like all “hot Saturns,” the exoplanet is similar in mass to Saturn and 20 percent bigger than Jupiter. It also orbits its parent star, WASP-96, very closely.

According to Sci-News, it only takes 3.4 days for the “hot Saturn” to complete a full orbit around WASP-96. Such close quarters with the parent star means that the exoplanet is very hot, reaching 1,881 degrees Fahrenheit (or 1,027 degrees Celsius).

Hot exoplanets, especially those as incandescent as WASP-96b, are typically known to have thick atmospheres, with plenty of clouds and hazes. The same goes for some of the coldest planets in the cosmos. However, this strange exoplanet doesn’t fit the mold, Nikolov’s team uncovered.

The researchers managed to take a close look at WASP-96b with the help of the European Southern Observatory’s Very Large Telescope (VLT) in Chile. Known as the world’s most powerful exoplanet-hunting telescope, the VLT enabled the team to gauge the composition of WASP-96b’s atmosphere as they observed the “hot Saturn” passing in front of its parent star.

Their observations pointed to a unique discovery, reveals a news release from the University of Exeter in the U.K., which led the study. For the first time ever, the astronomers found the complete fingerprint of sodium in the spectrum of an exoplanet. This discovery comes just a few days after the first-ever detection of helium in the atmosphere of exoplanet WASP-107b.

“Until now, sodium was revealed either as a very narrow peak or found to be completely missing,” said Nikolov, who is a research fellow at the British university.

Nevertheless, WASP-96b’s atmosphere was found to contain plenty of sodium, present in “levels similar to those found in our own solar system,” notes the news release.

According to the university, these high levels of sodium would make the “hot Saturn” appear bluish in color to a distant observer, because the sodium would absorb the yellow-orange light from the exoplanet’s full spectrum.

Finding sodium in WASP-96’s atmosphere led to another breakthrough. Since the spectral characteristics of sodium atoms can’t be observed in planets with thick atmospheres because their clouds would obscure the view — the element’s “tent-shaped” profile can only be spotted deep in a planet’ atmosphere, notes Nikolov — the team deduced that WASP-96b’s atmosphere has no clouds.

“WASP-96b is the only exoplanet that appears to be entirely cloud-free and shows such a clear sodium signature, making the planet a benchmark for characterization,” Nikolov pointed out.

This exoplanet’s “spectrum is in excellent agreement with cloud-free, solar-abundance models,” his team wrote in their paper, published yesterday in the journal Nature.

This important discovery has now given astronomers the opportunity to observe the full range of possible atmospheres on other planets, which can help shed more light into cloud formation and composition, noted Nikolov.

“WASP-96b will also provide us with a unique opportunity to determine the abundances of other molecules, such as water, carbon monoxide and carbon dioxide with future observations,” said study co-author Dr. Ernst de Mooij, from Dublin City University in Ireland. </s> Astronomers find exoplanet atmosphere free of clouds

May 7, 2018 , May 7, 2018 , University of Exeter

Artist rendition of 'hot Saturn' WASP-96b. A distant observer would see WASP-96b blueish in color, because sodium would absorb the yellow-orange light from the planet's full spectrum. Credit: Engine House

Scientists have detected an exoplanet atmosphere that is free of clouds, marking a pivotal breakthrough in the quest for greater understanding of the planets beyond our solar system.

An international team of astronomers, led by Dr Nikolay Nikolov from the University of Exeter, have found that the atmosphere of the 'hot Saturn' WASP-96b is cloud-free.

Using Europe's 8.2m Very Large Telescope in Chile, the team studied the atmosphere of WASP-96b when the planet passed in front of its host-star. This enabled the team to measure the decrease of starlight caused by the planet and its atmosphere, and thereby determine the planet's atmospheric composition.

Just like an individual's fingerprints are unique, atoms and molecules have a unique spectral characteristic that can be used to detect their presence in celestial objects. The spectrum of WASP-96b shows the complete fingerprint of sodium, which can only be observed for an atmosphere free of clouds.

The results are published in prestigious research journal Nature on May 7 2018.

WASP-96b is a typical 1300K hot gas giant similar to Saturn in mass and exceeding the size of Jupiter by 20%. The planet periodically transits a sun-like star 980 light years away in the southern constellation Phoenix, halfway between the southern jewels Fomalhaut (α Piscis Austrini) and Achernar (α Eridani).

It has long been predicted that sodium exists in the atmospheres of hot gas-giant exoplanets, and in a cloud-free atmosphere it would produce spectra that are similar in shape to the profile of a camping tent.

Nikolay Nikolov, lead author and from the University of Exeter said; "We've been looking at more than twenty exoplanet transit spectra. WASP-96b is the only exoplanet that appears to be entirely cloud-free and shows such a clear sodium signature, making the planet a benchmark for characterization.

A visualization of the transit of the WASP-96b in front of its host star. Credit: Ernst de Mooij

"Until now, sodium was revealed either as a very narrow peak or found to be completely missing. This is because the characteristic 'tent-shaped' profile can only be produced deep in the atmosphere of the planet and for most planet clouds appear to get in the way".

Clouds and hazes are known to exist in some of the hottest and coldest solar system planets and exoplanets. The presence or absence of clouds and their ability to block light plays an important role in the overall energy budget of planetary atmospheres.

"It is difficult to predict which of these hot atmospheres will have thick clouds. By seeing the full range of possible atmospheres, from very cloudy to nearly cloud-free like WASP-96b, we'll gain a better understanding of what these clouds are made of; " explains Professor Jonathan J. Fortney, study co-author, based at the Other Worlds Laboratory (OWL) at the University of California, Santa Cruz (UCSC).

The sodium signature seen in WASP-96b suggests an atmosphere free of clouds. The observation allowed the team to measure how abundant sodium is in the atmosphere of the planet, finding levels similar to those found in our own Solar System.

"WASP-96b will also provide us with a unique opportunity to determine the abundances of other molecules, such as water, carbon monoxide and carbon dioxide with future observations ", adds co-author Ernst de Mooij from Dublin City University.

Sodium is the seventh most common element in the Universe. On Earth, sodium compounds such as salt give sea water its salty taste and the white colour of salt pans in deserts.

In animal life, sodium is known to regulate heart activity and metabolism. Sodium is also used in technology, such as in the sodium-vapour street lights, where it produces yellow-orange light.

The team aims to look at the signature of other atmospheric species, such as water, carbon monoxide and carbon dioxide with the Hubble and James Webb Space Telescopes as well as telescopes on the ground.

'An absolute sodium abundance for a cloud-free 'hot Saturn' exoplanet ' is published in Nature on May 7 2018.

More information: N. Nikolov et al, An absolute sodium abundance for a cloud-free 'hot Saturn' exoplanet, Nature (2018). DOI: 10.1038/s41586-018-0101-7

Journal information: Nature

Provided by University of Exeter </s> NASA's Hubble Space Telescope has found an exoplanet 700 light-years from Earth with three times as much water as Saturn, indicating that it is a hot immigrant body that can reveal the origin of the planets.

Called WASP-39b, the scorching hot exoplanet has hot vapor and inflated atmosphere suggesting that the planet was bombarded with metal-rich ice during its origin. Its atmospheric temperature is in the range of 1,400 degrees Fahrenheit. Positioned 20 times closer to its star than Earth is to the Sun, it is tidally locked, meaning it always shows the same face to its star the way our moon is to Earth.

Its dayside temperature keeps powerful winds transport heat from the dayside to nightside as well and keep it permanently hot. "WASP-39b formed beyond the snow line in the planet-forming disk of the host star," says NASA's lead scientist Hannah Wakeford. "Exoplanets are showing us that planet formation is more complicated and more confusing than we thought it was."

Though researchers were not surprised to find water, they were startled by how much they found, which suggests that the planet formed farther out from the star, where it was bombarded by huge amounts of icy material. This gives out that WASP-39b must have formed differently from the famously ringed Saturn in our solar system.

The most-detailed ever study of the exoplanet was made possible when Hubble findings were studied in combination with the findings from other telescopes. Much like detectives who study fingerprints to identify the culprit, they used NASA's Hubble and Spitzer space telescopes to find the "fingerprints" of water in the atmosphere of a hot and bloated exoplanet.

Located in the constellation Virgo, WASP-39b orbits a quiet, Sun-like star, called WASP-39. Its mass is similar to our own Saturn but it clearly lacks rings. It was located so close to its star that it just takes four days to complete a revolution. What makes the planet unique is that it is an alen planet that might have gate-crashed into the current solar system, said scientists who were upbeat about their new findings.

Wakeford is gearing up for the next NASA's James Webb Space Telescope, to be launched in 2019, - to get an even more complete spectrum of the exoplanet, including the planet's atmospheric carbon, which absorbs light at longer infrared wavelengths than Hubble can see. The amount of carbon and oxygen in the atmosphere provides clues for scientists to learn more about where and how this planet formed.
A study has been revealed that WASP-104b, a hot Jupiter exoplanet, has been discovered as one of the darkest exoplanets ever seen.