Two years ago, scientists detected a super-flare from the Sun’s neighboring star Proxima Centauri. The Red Dwarf, located some 4.25 light years away from our planet, sits at the bottom on the scale of stars, but the eruption baffled scientists, hinting that similar flares may have wiped out life on Earth’s closest exoplanet, if it had any.

Proxima Centauri is believed to host at least one Earth-sized rocky planet, dubbed Proxima b, in the habitable zone — the region where a planet is far enough from its star to have liquid water and bolsters the chances of finding life. But, the thing is even if Proxima b had any life, it might have been destroyed by the occurrence of intense flares, Allison Youngblood, a postdoctoral fellow at NASA's Goddard Space Flight Center, and her team estimated.

The solar flare detected back in 2016 was 10 times larger than previous ones and one of the strongest ever detected from a star this size. It unleashed 316,227 petawatts of energy and grew in brightness by a whopping factor of 68. At this level, even humans on Earth would have seen the faint star shining in the night sky, Popular Mechanics reported.

Using those observations and sophisticated modeling techniques, scientists predict at least five such flares erupt from the small star every year. This could mean serious trouble for Earth’s closest exoplanet and trim down the possibility of microbial life survival on its surface.

According to the astronomers, regular interactions between the flares and planetary atmosphere could drastically affect Proxima b's atmosphere. For a planet similar to Earth, flares of such magnitude would weaken the ozone layer progressively and deplete it by a whopping 90 percent in a matter of five years. And if this goes on for a few hundred thousand years, the ozone layer would be removed completely, leaving the planet unprotected from its star's harmful ultraviolet radiation.

"Then, if another one of these superflares comes along and there is no ozone protection, the UV radiation incident on the planet's surface would kill even the most radiation-resistant organisms," Youngblood said in a journal article preprint.

With that, the astronomers also note that if the atmosphere of the planet survives superflare impacts in the long-run, microscopic organisms will have to undergo complex adaptations to survive on the planet, just like how lichens evolved for extreme environments with features like UV-protecting pigments, ArsTechnica reported. Scientists around the world are working to better understand the impact of stellar flares in distant systems and how they could affect the possibility of life.

The ArXiv.org preprint paper titled “The first naked-eye superflare detected from Proxima Centauri” was made available on April 5 and is set to be published in the AAS Journals. </s> We've observed an alien world orbiting Barnard's Star, a tiny red dwarf that's only six light-years away, making it the second-closest known exoplanet beyond our solar system. Known as a "super-Earth," the planet (designated Barnard's Star b, or GJ 699 b) is thought to be at least 3.3 times the mass of Earth and orbits its star once every 233 days.

Barnard's Star is the fourth-closest star to our sun. Alpha Centauri's triple-star system (including Alpha Centauri A and B, plus Proxima Centauri) are the only stars nearer. Proxima Centauri is the closest star to have a known exoplanet in orbit, Proxima Centauri b. That world is slightly more massive than Earth, is located only 4.2 light-years away and has been pelted by solar flares, dashing hopes of it hosting life.

While an exciting (and historic) find, you can forget about Barnard's Star b bearing any resemblance to our planet. Barnard's Star is a very low mass and dim red dwarf that produces only 0.4 percent of the radiant power our sun generates. That means its "habitable zone" is extremely compact, and the exoplanet orbits beyond the star's "snow line." The snow line around any star is the distance beyond which water cannot exist in a liquid state on a planet's surface. The exoplanet has a predicted surface temperature of -170 degrees Celsius (-274 F), making it wholly incompatible for life (as we know it, anyway).

Still, this new exoplanetary discovery is exciting. Super-Earths are like nothing we have in our solar system and have only been discovered orbiting other stars more distant than Barnard's Star. These alien worlds occupy the mass range between the small rocky planets (like Earth, Mars and Venus) and the larger gaseous planets (like Neptune). Knowing that we have one of these strange exoplanets so nearby could allow us to get to know this planetary species a little better.

Although it's on our interstellar doorstep, discovering the Barnard's Star super-Earth took an international team of astronomers using decades of spectroscopic data of the star to find it.

"For the analysis we used observations from seven different instruments, spanning 20 years, making this one of the largest and most extensive datasets ever used for precise radial velocity studies," said Ignasi Ribas, of the Institut de Ciènces de l'Espai (ICE, CSIC), Spain, in a statement. Ribas is the first author of the study published in the journal Nature.

The radial velocity method used in exoplanet hunting requires precise observations of a star's spectrum. When starlight is received by telescopes, its spectrum can be split into its component wavelengths — such as infrared, visible and ultraviolet. However, if astronomers record observations of this starlight over many years, they may notice slight periodic frequency shifts. This is how we find exoplanets actually: As they orbit their host stars, their gravity causes their stars to wobble, pulling them toward and away from the telescope on Earth, creating a frequency shift that corresponds to the exoplanet's mass orbital period. Unlike NASA's Kepler and new Transiting Exoplanet Survey Satellite (TESS) – which both detect the slight dimming of starlight as an exoplanet orbits in front of its host star (known as a "transit") – the radial velocity method doesn't depend on detecting this dip in light to realize the presence of exoplanets around stars.

"This technique has been used to find hundreds of planets," said collaborator Paul Butler, of Carnegie Institution for Science and one of the pioneers of the radial velocity method, in a statement, "We now have decades of archival data at our disposal. The precision of new measurements continues to improve, opening the doors to new parameters of space, such as super-Earth planets in cool orbits like Barnard's Star b."

Since this exoplanet is so close, astronomers hope that they will be able to use it as a target for the next generation of space telescopes, such as the planned NASA Wide Field Infrared Survey Telescope (WFIRST). This makes Barnard's Star b a prime candidate for us to use powerful spectroscopic techniques to, one day, peer into its atmosphere (if it has one) and understand what it's really made of. </s> Amid much excitement in 2016, astronomers revealed the discovery of an Earth-sized planet around Proxima Centauri, the star closest to our Sun. This exoplanet, just 4.2 light years from Earth, was close enough to its red dwarf star that water might well exist on its surface.

Alas, now we know that life probably does not live on the planet, at least not on the surface. In March 2016, astronomers using an array of telescopes known as Evryscope observed a "superflare" 10 times larger than any previous one detected from the red dwarf star. Based on these observations and those of other instruments with spectrographs, the astronomers determined that about five of these superflares occur in a given year.

In an unpublished paper that describes their use of a model for interactions between the flares and a planetary atmosphere, the astronomers suggest such extreme solar activity would reduce the ozone of an Earth-like atmosphere by 90 percent within just five years, with complete depletion occurring within a few hundred thousand years. This means that ultraviolet light observed in the recent superflare reached the surface with 100 times the intensity needed to kill even microbic life that is resistant to UV light.

"Recent results have suggested that some more complex life such as lichens evolved for extreme environments and with adaptations such as UV-screening pigments may survive these radiation levels," the astronomers write in a journal article preprint. "This suggests that life on Proxima b will have to undergo complex adaptations to survive, even if the planetary atmosphere survives the long-term impact of the stellar activity."

That's too bad, because Proxima b has some intriguing characteristics. The planet is probably rocky, rather than a gas giant, and it's tidally locked to its star, meaning one side is always sunny while the other is perpetually gloomy. Therefore, if the planet does have an atmosphere, the surface temperature may vary from +30 degrees Celsius on the light side to -30 degrees Celsius on the dark side. These conditions would allow water, if the planet has any, to exist on the surface of the world as a liquid at some locations.

The arXiv. Abstract number: 1804.02001 (About the arXiv). Submitted to AAS Journals. </s> In the two years since astronomers confirmed the existence of an Earth-like planet just outside the Solar System, scientists have scrambled to determine Proxima b’s habitability.

Unfortunately, multiple studies proved disheartening, often indicating that the orb’s sun experiences too much flare activity to sustain an atmosphere or liquid water on its surface.

New NASA-led research, however, suggests Proxima b—which orbits red dwarf Proxima Centauri, the closest known star to our galaxy—could have enough water to support life.

Don’t get too excited about meeting the intergalactic neighbors just yet, though.

As indicated by those earlier studies, there is a lot working against aliens’ favor on Proxima b, which is just 1.3 times the mass of Earth.

While the planet looks good on paper, its history remains unclear: It probably experienced a runaway greenhouse effect (ultimately boiling away any oceans), and would have been pelted with intense radiation (X-ray and extreme ultraviolet fluxes) and solar wind.

It could also be home to an entirely new category of being.

“First and foremost, we don’t know whether Prox b even has an atmosphere and if it does, whether it has any water. Without those, life as we know it cannot exist,” study co-author Anthony Del Genio, of NASA’s Goddard Institute for Space Studies, told Universe Today.

“It could be [that] Prox b formed initially with no atmosphere, or that it formed with an atmosphere but in a stellar system that was water-poor,” he continued. “Or it could have formed with a modest atmosphere and lots of water. Or it could have formed with a very thick atmosphere. We just don’t know yet.”

The research—conducted by Del Genio and colleagues at the NASA Goddard Space Flight Center, Columbia University, and IT firm Trinnovim LLC—was published in the journal Astrobiology.

There are any number of reasons to assume no one lives on Proxima b, including the fact that M stars like Proxima Centauri tend to be too small, cool, bright, and active to sustain a habitable climate.

But that’s no reason to give up on the hunt.

Using a little imagination and a lot of high-tech software, Del Genio & Co. conceptualized Proxima b as having an atmosphere and water, in an effort to understand how those factors might produce habitable conditions* at the surface.

*Defined as: warm enough to sustain liquid water, but not so hot as to evaporate it all.

The team modeled a range of potential atmospheres, including ones like Earth (dominated by nitrogen with small amounts of CO2) and Mars (pure CO2).

According to Universe Today, they also considered things like whether its atmosphere would be thinner or thicker than ours, its oceans more or less salty, and whether the sea covers the entire planet.

In every case the scientists could dream up, Proxima b had at least some surface liquid water, giving it a “pretty good chance” of being habitable, Del Genio said.

“We also found that the ocean currents carried warm water from the dayside to the nightside, keeping parts of the nightside habitable even though they never see any light,” he added. “And if the ocean is very salty, almost the entire planet could be covered by liquid, but with temperatures below the usual freezing point almost everywhere.”

NASA’s planet hunter TESS (Transiting Exoplanet Survey Satellite), meanwhile, has begun providing data on planets beyond our Solar System.

The study of exoplanets has seen remarkable discoveries in the past decade, including a series of orbs that could host alien life. But some folks still want more. Read all about outer space here.

Let us know what you like about Geek by taking our survey. </s> For most of human history, people wondered if there were other planets out there in the unfathomable reaches of space. It turns out there are some very close to Earth, though. A team of astronomers has revived interest in Barnard’s Star, which hangs in space just six light years away. After dismissing evidence for an exoplanet orbiting this star in the 1970s, the team now says there’s a very good chance Barnard’s Star does indeed host a super-Earth.

Barnard’s Star is a red dwarf and one of the closest stars to Earth. Only the Centauri system is closer, and we know there’s at least one exoplanet there. Astronomers announced the discovery of Proxima Centauri b with great fanfare in 2016. At just 4.4 light years away, this planet will make an excellent target for future observation. The planet orbiting Barnard’s Star is just a little bit more distant, but it’s still close enough to be key to understanding exoplanets.

The tale of planet hunting around Barnard’s Star starts in the 1960s when astronomer Peter van de Kemp released compelling data supporting the existence of an exoplanet. However, other teams were unable to confirm, and by the 1970s we knew the discovery was merely a product of defective instruments. Scientists kept looking at the star, and now astronomers from the Institute of Space Studies of Catalonia and the Institute of Space Sciences in Spain have assembled 20 years of data to reveal Barnard’s Star b.

The newly published study lays out the basics of the exoplanet. Barnard’s Star b completes an orbit of the star every 233 Earth days. It’s about as far away from Barnard’s Star as Mercury is from Earth, but Barnard’s Star is much cooler. So, it’s distinctly outside the habitable zone with a surface temperature of -170 degrees Celsius (-274 degrees Fahrenheit). It’s the equivalent of a planet orbiting between Mars and Jupiter in our solar system. Barnard’s Star b has a mass about three times that of Earth, but we don’t know its size or composition yet. We suspect it’s rocky, though.

Barnard’s Star b does not transit in front of its host star from Earth’s perspective — that would have made detection vastly simpler. Instead, the team used the radial velocity method. They watched for small counter movements in the star that indicate a massive body (a planet) is in orbit. A smaller star like Barnard’s Star wobbles more than a more massive one, so even a small-ish planet like this one had some detectable effect.

The team claims high confidence that Barnard’s Star b is real, but other teams will need to confirm. We don’t want another van de Kemp scenario.

Now read: There’s an Earthlike planet orbiting our nearest neighbor, Proxima Centauri – but how might we actually get there?, Massive Solar Flares Diminish Chance of Finding Life on Proxima Centauri, and So Long, and Thanks for All the Planets: NASA Retires the Kepler Telescope </s> The study was co-led by researchers from Queen Mary University of London, and from the Institut d'Estudis Espacials de Catalunya and the Institute of Space Sciences/CSIC in Spain.

The potentially rocky planet, known as Barnard's star b, is a 'super-Earth' with a mass of at least 3.2 times that of the Earth, and it orbits around its host star once every 233 days.

The results, published in the journal Nature, show the planet lies at a distant region from the star known as the 'snow line'. This is well beyond the habitable zone in which liquid water, and possibly life, could exist.

The planet's surface temperature is estimated to be around -170 degrees Celsius meaning it is likely to be a frozen world which is uninviting to Earth-like life.

However, if the planet has a substantial atmosphere the temperature could be higher and conditions potentially more hospitable.

Dr. Guillem Anglada Escudé, from Queen Mary's School of Physics and Astronomy, said: "Barnard's star is an infamous object among astronomers and exoplanet scientists, as it was one of the first stars where planets were initially claimed but later proven to be incorrect. Hopefully we got it right this time."

At nearly six light-years away Barnard's star is the next closest star to the Sun after the Alpha Centauri triple system.

It is a type of faint, low-mass star called a red dwarf. Red dwarfs are considered to be the best places to look for exoplanet candidates, which are planets outside our solar system.

Barnard's star b is the second closest known exoplanet to our Sun. The closest lies just over four light-years from Earth and was also discovered by a team led by Queen Mary's Dr. Anglada Escudé in 2016. That exoplanet, called Proxima b, orbits around the red dwarf star Proxima Centauri.

The researchers used the radial velocity method during the observations that led to the discovery of Barnard's star b. This technique detects wobbles in a star which are likely to be caused by the gravitational pull of an orbiting planet.

These wobbles affect the light coming from the star. As the star moves towards the Earth its spectrum appears slightly shifted towards the blue and, as it moves away, it is shifted towards the red.

This is the first time that this technique has been used to detect a planet this small so far away from its host star.

The researchers re-examined archive data obtained over a 20-year period, and added new observations with the latest generation of instruments, namely the CARMENES spectrometer in Spain, the ESO/HARPS instrument in Chile and the HARPS-N instrument in the Canary Islands.

This wealth of data provided the extraordinary accuracy needed to identify the influence of the planet with near certainty. The wobble observed in the star's motion corresponds to speeds of only just over 1 metre per second—about walking speed.

Dr. Ignasi Ribas, from Institut d'Estudis Espacials de Catalunya and the Institute of Space Sciences in Spain, said: "After a very careful analysis, we are over 99 per cent confident that the planet is there, since this is the model that best fits our observations. However, we must remain cautious and collect more data to nail the case in the future."

Further observations to increase the confidence of this result are already under way at various observatories, and the system is an excellent candidate for observation by the next generation of instruments specifically designed to image exoplanets directly, such as NASA's planned Wide Field Infra Red Survey Telescope (WFIRST).

If the planet can be observed directly it will provide vital information about its properties and extend our understanding of the kinds of planets that form around red dwarf stars.

An award-winning public engagement campaign, known as Pale Red Dot, allowed the public to follow in real time the observations and analysis that led to the discovery of Proxima b.

The public have also been able to follow the observations leading to this new discovery, a result of extending the search to other very nearby red dwarfs, via a similar web-based campaign known as the Red Dots project, @reddotsspace on Twitter).

The study includes contributions from Professor Richard Nelson and research student John Strachan, both members of Queen Mary's School of Physics and Astronomy.

This research was supported in part by the UK Science and Technology Facilities Council and a Queen Mary University of London Principal's Postgraduate Studentship.

Explore further: Assist astronomers' new hunt for Earth-like planets

More information: I. Ribas et al. A candidate super-Earth planet orbiting near the snow line of Barnard's star, Nature (2018). DOI: 10.1038/s41586-018-0677-y
Proxima Centauri b, an Earth-like exoplanet, is hit with a deadly superflare.