Gliese 251 is an early red dwarf star, ranking as the 74th closest star system to our Sun.
An artistic interpretation of the Gliese 251 system. Featuring Gliese 251c (left), its host star (right), and the already discovered planet Gliese 251b (center). Image credit: Michael Marcheschi / m2design.
You can find Gliese 251 as a bright M dwarf star, located at a distance of 5.58 parsecs (18 light years) in the constellation of Gemini.
Also known as GJ 251, HD 265866, or Wolf 294, this star is believed to host at least two super-Earths, Gliese 251b and Gliese 251c.
Initially discovered in 2020, Gliese 251b has a mass of 3.85 Earth masses and completes an orbit in 14.2 days.
The newly identified exoplanet, Gliese 251c, boasts a mass of 3.84 times that of Earth and has an orbital period of 53.6 days.
“With so many exoplanets now known, discovering new ones may not seem significant,” remarked Paul Robertson, an astronomer at the University of California, Irvine.
“The exceptional aspect is that its host star is nearby, roughly 18 light-years distant. From a cosmic perspective, it’s essentially in our neighborhood.”
Gliese 251c was detected using the Habitable Zone Planet Finder (HPF), a state-of-the-art near-infrared spectrometer mounted on the Hobby-Eberly Telescope at McDonald Observatory in Texas.
This planetary signal was subsequently validated using the NEID spectrometer at Kitt Peak National Observatory in Arizona.
Corey Beard, Data Scientist at Design West Technologies, states:
“While the discovery is statistically significant, we are still assessing the state of the planet due to instrument and methodological uncertainties.”
“Direct imaging of this candidate will rely on the next generation of telescopes and community investment.”
Given Gliese 251c’s closeness to Earth, it stands out as a prime candidate for future direct imaging studies utilizing the Thirty Meter Telescope (TMT).
The TMT, with its large mirror, could potentially directly image dim exoplanets like Gliese 251c and verify the presence of water.
“TMT is anticipated to be the only telescope capable of capturing such details. These images will pertain to exoplanets,” Dr. Beard added.
“Such imaging isn’t feasible with smaller telescopes.”
The results from the research team were published in Astronomy Magazine.
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Corey Beard et al. 2025. Discovery of a nearby super-Earth candidate located in the habitable zone, suitable for direct imaging. A.J. 170, 279; doi: 10.3847/1538-3881/ae0e20
Astronomers are making strides in exploring the TRAPPIST-1 system with the NASA/ESA/CSA James Webb Space Telescope, showcasing its remarkable capability to glean detailed data about the exoplanet atmospheres and effectively utilize this information. The initial findings stem from Webb’s observation of TRAPPIST-1e. Although the first four observations by Webb are not adequate to fully assess the atmosphere, scientists are using the data to refine the possibilities for these planets, including the presence of oceans similar to those on Earth and a methane-rich environment akin to Saturn’s moon Titan. Meanwhile, additional innovative observations from Webb are ongoing, revealing the unique characteristics of TRAPPIST-1e.
The Earth-sized Exoplanet TRAPPIST-1E is illustrated in the bottom right as it eclipses the flare host star in this artist’s representation of the TRAPPIST-1 system. Image credits: NASA/ESA/CSA/STSCI/JOSEPH OLMSTED, STSCI.
TRAPPIST-1 is a cool dwarf star located in the Aquarius constellation, approximately 38.8 light-years away.
The stars are only slightly larger than Jupiter and possess a mere 8% of the solar mass. They rotate rapidly and emit UV energy flares.
TRAPPIST-1 harbors seven transiting planets designated TRAPPIST-1b, c, d, e, f, g, and h.
All these planets are comparable in size to Earth and Venus, or slightly smaller, with remarkably short orbital periods: 1.51, 2.42, 4.04, 6.06, 9.21, 12.35, and 20 days, respectively.
It is possible that they could be tidally locked, meaning the same side is always facing the host star, resulting in a perpetual day and night side for each TRAPPIST-1 planet.
Among the seven planets, TRAPPIST-1E is of particular interest if it possesses an atmosphere, as its surface water is situated at a theoretically viable distance from the star.
The Space Telescope Science Institute and colleague Dr. Néstor Espinoza aimed the Webb’s NIRSpec (near-infrared spectrometer) instrument at TRAPPIST-1e during its transits in front of the star.
As starlight filters through the planet’s atmosphere, it can be partially absorbed, revealing the specific chemicals present by the resulting dips in the light spectrum that reaches Webb.
As more transits are analyzed, the clarity regarding the atmospheric composition improves.
With only four transits analyzed thus far, numerous possibilities remain open for TRAPPIST-1E, though researchers speculate that it lacks a significant primary atmosphere.
Given TRAPPIST-1’s active nature and frequent flares, it’s not unexpected that the potential hydrogen-helium atmosphere of the planet could have been stripped away by stellar radiation.
However, many planets, like Earth, develop a denser secondary atmosphere after losing their initial one.
TRAPPIST-1E may not have the capacity for this and could potentially lack a secondary atmosphere.
“We have devised a novel method to analyze Webb’s data to assess the potential atmosphere and surface conditions of TRAPPIST-1E,” said the scientist.
It appears unlikely that TRAPPIST-1e’s atmosphere is largely composed of carbon dioxide, reminiscent of Venus’s thick atmosphere or Mars’s thinner one.
Nonetheless, astronomers should be cautious, as there are no direct parallels to our solar system.
“Because TRAPPIST-1 is significantly different from our Sun, the surrounding planetary systems also exhibit notable differences, posing challenges to both observational and theoretical frameworks,” remarked Dr. Nicole Lewis of Cornell University.
“If TRAPPIST-1E has liquid water, it would require a greenhouse effect. This effect incorporates various gases, especially carbon dioxide, which help stabilize the atmosphere and maintain a warm environment on the planet.”
“A minimal greenhouse effect is beneficial, and measurements do not exclude the presence of carbon dioxide necessary to preserve water on the surface.”
The team’s analysis suggests that water could exist as global oceans or be distributed in smaller, ice-encased regions at midday.
This is due to the size of the TRAPPIST-1 planets and their orbital sizes, all of which are thought to be tidally locked, with one side perpetually facing the star and the other shrouded in darkness.
“They’re remarkable,” stated Dr. Anna Glidden, an astronomer at the Kavli Institute for Astrophysics and Space Research at MIT.
“This is an astounding measurement of starlight around an Earth-sized planet located 40 light-years away, providing insights into potential life there if conditions permit.”
“It’s thrilling to be part of this new era of exploration.”
Néstor Espinoza et al. 2025. JWST-TST Dreams: NIRSpec/Prism transmission spectroscopy of the planet TRAPPIST-1e. ApJL 990, L52; doi: 10.3847/2041-8213/adf42e
Anna Glidden et al. 2025. JWST-TST Dreams: Secondary atmosphere constraints of the habitable zone planet TRAPPIST-1e. ApJL 990, L53; doi: 10.3847/2041-8213/adf62e
The planetary candidate, Alpha Centauri AB, may be a gas giant orbiting at a distance of one to two times that of the Earth from the Sun, as indicated in two research papers. Astrophysics Journal Letter. If verified, this planet would be the closest known to Earth within the habitable zone of a Sun-like star. Nonetheless, since it is a gas giant, astronomers do not believe it could support life as we understand it.
Artist’s rendering of the gas giant Alpha Centauri A. Image credits: NASA/ESA/CSA/STSCI/Robert L. Hurt, Caltech & IPAC.
Alpha Centauri resides in the Centaurus constellation and represents the nearest star system to Earth.
Also referred to as Rigil Centaurus, Rigil Kent, and Griese 559, this system includes a bright binary star pair, Alpha Centauri A and Alpha Centauri B, alongside a fainter red star known as Alpha Centauri C.
The two prominent stars are approximately 4.35 light-years away, while Alpha Centauri C, commonly called Proxima Centauri, is slightly nearer at about 4.23 light-years.
In comparison to the Sun, Alpha Centauri A is a G2-type star similar in nature, but slightly larger (1.1 times the size of the Sun and around 1.5 times its luminosity).
Alpha Centauri B, classified as a K1-type star, is slightly smaller and less luminous (approximately 0.9 times the mass of the Sun, with about 45% of its visual brightness).
These two stars orbit around a common center of gravity approximately every 80 years, maintaining a minimum distance of about 11 times that of the Earth-Sun distance.
Astronomers study these stars closely along with our nearest interstellar neighbor, Proxima Centauri, making them prime targets in the search for potentially habitable planets.
“This proximity offers the best chance to gather data on planetary systems beyond our own,” stated Dr. Charles Beichman from NASA’s Jet Propulsion Laboratory and the Exoplanet Science Institute at IPAC Astronomy Center in California.
“However, the brightness and swift motion of these stars present significant challenges in observation, even for the world’s most advanced space telescopes.”
The Alpha Centauri star system captured by different terrestrial and space-based observatories: DSS, Hubble Space Telescope, and James Webb Space Telescope. While the DSS shows the triple system as one light source, Hubble distinguishes between Alpha Centauri A and B. Webb’s Milimask image mitigates glare from Alpha Centauri A via a coronagraphic mask. Image credits: NASA/ESA/CSA/ANIKET SANGHI, CALTECH/CHAS BEICHMAN, NEXSCI, NASA & JPL-CALTECH/DIMITRI MAWET, CALTECH/JOSEPH DEPASQUALE, STSCI.
The first observations of this system occurred in August 2024, employing a Coronagraphic Mask with Webb’s Mid-Infrared Instrument (MIRI) to reduce the brightness of Alpha Centauri A.
The presence of nearby companion star Alpha Centauri B added complexity to the analysis, but astronomers successfully subtracted the light from both stars, uncovering objects that were more than 10,000 times dimmer than Alpha Centauri A.
On the other hand, an initial detection was promising, but further data was required for a definitive conclusion.
However, subsequent observations in February and April of 2025 did not unveil any objects akin to those detected in August 2024.
“We are facing a case of disappearing planets,” remarked Dr. Aniket Sangi from Caltech.
“To unravel this mystery, we employed computer models simulating millions of potential orbits, taking into account the insights gained from observing planets and their absence.”
In the simulations, the team incorporated the 2019 sightings of potential exoplanet candidates reported by the ESO’s Very Large Telescope, alongside new data from Webb, considering the gravitational stability of orbits influenced by Alpha Centauri B.
“The non-detections in the second and third rounds with Webb were not unexpected,” stated Sangi.
“In many simulated orbits, the planet was positioned too close to the star, rendering it invisible to Webb during both February and April 2025.”
“Based on mid-infrared observations of planetary brightness and orbital simulations, this gas giant could have a mass similar to Saturn, orbiting Alpha Centauri A at a distance one to two times greater than that between the Sun and Earth.”
“If confirmed, the potential planets identified in Webb’s Alpha Centauri images will represent a significant milestone in exoplanet imaging efforts,” Sangi added.
“Of all directly imaged planets, this would be the closest star we have ever observed.”
“Moreover, it would be the nearest to our home, with gas giants in our solar system that are similar in temperature and age to Earth.”
“The mere existence of two closely separated star systems poses intriguing challenges to our understanding of planetary formation, survival, and evolution within chaotic environments.”
If substantiated by further observations, these findings could reshape the field of exoplanet science.
“This will become a pivotal object in exoplanet research, offering multiple opportunities for detailed characterization by Webb and other observatories,” Dr. Beichman concluded.
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Charles Beichman et al. 2025. The Neighbor World: Imaging a giant planet candidate, orbital and physical properties of CEN A, and habitable zones at the exozodiacal upper limit. ApJL in press; Arxiv: 2508.03814
Aniket Sangi et al. 2025. The Neighbor World: Imaging a giant planet candidate in the habitable zone of Cen A. II. Binary Star Modeling, Planetary and Exozodiacal Search, and Sensitivity Analysis. ApJL in press; Arxiv: 2508.03812
Trilobites were a varied group of ancient marine arthropods. While many inhabited the seabed, some took to more mobile lifestyles. Recent research has clarified the evolutionary lineage of a peculiar group of trilobites known as cyclopizids, named after the legendary one-eyed creature, Cyclops.
Cyclopygid Trilobite Symphysops Stevaninae. Image credit: Francisco J. López-Soriano & Joan Corbacho, https://www.elfosil.com via Bataleria.
Mirobiaceae was an ancient aquatic creature (arthropod) that existed from 521 million years ago (MA) until around 252 MA.
Approximately 21,000 species are known, representing numerous ecological niches. Most thrived on the seabed (benthic), while some ventured into the open ocean (pelagic).
Despite their diversity, our understanding of their comprehensive evolutionary history remains limited.
Strange groups of Ordovician trilobites (485-444 MA) are referred to as Cyclopizids. They possess 5-7 body (thoracic) segments, and the cephalon lacks typical spines.
The name Cyclopizid is derived from the mythical Greek cyclops, as their eyes evolved to merge into a single large visual surface, enhancing their field of vision.
Cyclopygids inhabited the deep, dark zones of the ocean (mesopelagic), swimming at the lower edge of the illuminated region, known as the Twilight Zone, where they actively hunted small organisms (zooplankton).
Some Cyclopygids, such as Pricyclopyge, may have swum upside down and featured bioluminescent structures on their third thoracic segment.
Recent research has elucidated the evolutionary history of the 47 cyclopygid genera through cladistic analysis, a method that categorizes organisms based on shared derived traits.
The family predominantly found in China, Tai Hungshaniidae, is connected to the Nileidae and Cyclopidiidae families. Illaenopsis is expected to be included.
As cyclopizids evolved, they adapted to a more transparent lifestyle, which included larger eyes shifting towards the edges of the thorax, a reduction in the number of thoracic segments, size decrease, and enhanced streamlining.
These cyclopizids, which occupy higher positions in the water column, usually reside closer to the coasts.
Mapping the depths they are interpreted to inhabit on our evolutionary trees reveals that cyclopizids positioned near the base tend to inhabit shallow waters.
Consequently, cyclopizids gradually transitioned into deeper waters, adapting more to a pelagic lifestyle.
This paper will be published in the journal Historical Biology.
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SJ Braddy, La Dale & H. Wang. 2025. Phylogenesis of cyclopide trilobites. Historical Biology. doi:10.1080/08912963.2025.2501330
As an earthquake ruptures along the Cascadia subduction zone fault, much of the US West Coast will experience intense shaking for five minutes, with tsunamis potentially generating waves up to 100 feet crashing towards the shore. However, this is only the onset of anticipated devastation.
Even if coastal communities in Northern California, Oregon, and Washington withstand the initial earthquake, recent research indicates that flooding could inundate many of these susceptible regions. This is due to an expected drop of 6½ feet in the entire coastal land when the earthquake strikes, according to a new study published Monday in the Proceedings of the National Academy of Sciences (PNA).
Researchers examined earthquake and flood models to provide some of the most comprehensive predictions about how Cascadia earthquakes can lower or subside coastal land, potentially affecting over twice as many people, structures, and roadways as currently established. The exacerbating effects of climate change are projected to raise sea levels, compounding the issue over time.
“The repercussions of these hazards will linger for decades or even centuries following the earthquake,” stated Tina Dura, the study’s lead author. “Tsunamis will strike and have a considerable impact. Don’t misunderstand me; however, a lasting change in flood frequency… that is a critical concern.”
The team will operate the Vibracore Rig in Silets Bay, Oregon, collecting deep sediment cores in 2022 for tsunami deposits and paleoseismic analysis. Tina Dura
Dura explained that geological fossil evidence suggests that previous Cascadia earthquakes resulted in a significant drop in land level, transforming once dry areas into tidal mud flats along the Pacific Northwest’s estuaries.
An assistant professor of geoscience at Virginia Tech, Dura noted: “This is how we have a harbor…and where we’ve established towns, yet that land will plummet by a maximum of two meters.”
The Cascadia subduction zone fault offshore of North America presents an imminent threat, capable of generating magnitude 9.0 earthquakes. Such events are expected to occur on average every 450-500 years, with the last major quake dating back to 1700.
The national seismic hazard model indicates a 15% chance of an earthquake measuring 8.0 or higher occurring along the zone within the next 50 years.
When the fault ruptures, experts assert that it could lead to the most catastrophic natural disaster in the nation’s history. Simulations from 2022 predict that the Cascadia earthquake could damage around 620,000 buildings in the Pacific Northwest, including 100 hospitals and 2,000 schools, resulting in over 100,000 injuries and approximately 14,000 fatalities.
Recent findings emphasize that coastal planners must seriously consider not only the immediate threats of strong shaking and tsunami waves but also the long-term impacts of land reshaping and rapid subsidence of the coastline itself.
“There will be the flooding itself, as well as enduring changes in land elevation along the coast, greatly affecting community planning,” remarked Harold Tobin, director of the Pacific Coast Earthquake Network and professor at the University of Washington. “Where will schools and hospitals be built? Where will transportation networks be established? A long-term perspective is vital.”
Following the earthquake, Dura’s research predicts that towns along the Pacific Northwest coastline, such as Seaside, Oregon, Westport, Washington, and Aberdeen, Washington, will likely experience frequent flooding, at least once every century.
The study also highlights that climate change-induced sea level rise will accelerate, aggravating the consequences of post-earthquake flooding in the future.
A field team across the mouth of the Salmon River in Oregon will transport coring and surveying equipment to the next sampling site in 2023. Mike Pridy
Global average sea levels have risen by approximately 8-9 inches since 1880, according to the National Oceanic and Atmospheric Administration (NOAA). Dramatic acceleration in sea level rise is anticipated in the coming decades due to global warming, with NOAA estimating an increase of 10-12 inches.
The impact of sea level rise varies depending on location and can significantly affect the coastline.
In places like Chesapeake Bay, Virginia, land is gradually sinking, a process termed subsidence, while portions of the Pacific Northwest are experiencing uplift due to continental movements. This uplift can offset some of the sea level rise.
The uplift is attributed to the stress build-up within the plates forming the Cascadia subduction zone. In this zone, the Juan de Fuca plate is forced beneath the North American plates, causing a slight upward movement of land.
Currently, the subduction zone faults remain inactive, accumulating stress. When the fault eventually ruptures, the released plate bow leads to rapid land-level subsidence, effectively negating the uplift for centuries.
“It all transpires in a matter of minutes, resulting in meter-level drops,” stated Dura. “The land continues to shift, and as I mentioned, this has ramifications that will last for decades and centuries. Consequently, the critical areas of the floodplain are significantly impacted.”
High-tech companies are urging the UK government to support the growth of AI data centers in remote areas of the UK by offering the lowest electricity prices in Europe.
A report commissioned by high-tech companies Amazon and Openai calls on the government to reform the UK electricity market by implementing zonal pricing, where prices vary based on different zones to incentivize investment in areas with lower electricity costs.
This zonal pricing model, according to a report by SMF Think Tank, highlights Scotland as a hotspot for AI data centers due to its abundant wind farms and population density.
Political leader Keir Starmer has emphasized the importance of artificial intelligence in positioning the UK as a global technology leader.
However, concerns have been raised about hosting data centers in the UK due to high industrial electricity prices and ambitious targets to phase out fossil fuels from the electricity system.
The SMF report suggests that zonal pricing could significantly reduce electricity costs for data centers, making Scotland’s electricity prices the lowest in Europe.
Support for zonal pricing has been recommended by cross-party Think Tanks to expedite the deployment of AI data centers by connecting more low-carbon electricity to the grid and addressing planning delays.
The report also backs the government’s plan to build small modular reactors outside traditional nuclear areas to facilitate the development of Data Centre Hubs in England and Wales.
According to Sam Robinson of SMF, urgent action is needed to address rising energy costs and planning delays to maintain the UK’s position as a global innovation leader.
Zone pricing alignment has garnered support from SMF clients and tech companies in government consultations on the future of electricity markets.
The proposed zoning system aims to attract high-energy users to regions with lower electricity prices, creating new job opportunities outside of southeastern England while balancing demand on the local grid.
However, concerns have been raised that changes in energy pricing may impact profitability of remote clean energy projects, potentially hindering investment in green energy.
The government is expected to make a decision on the future of the electricity market in the coming months.
According to a team of geoscientists from the University of Maryland and the University of Maryland, between 250 million and 120 million years ago during the Mesozoic Era, the ancient ocean floor was formed by the East Pacific Rise, a plate boundary at the bottom of the southeastern Pacific Ocean. It is said to have sunk deep into the earth. University of Alberta.
A map of the East Pacific Ridge region where the ancient ocean floor was discovered. Image credit: Jingchuan Wang.
University of Maryland researcher Jingchuan Wang and his colleagues used innovative seismic imaging techniques to look deep into the Earth's mantle, the layer between the Earth's crust and core.
They discovered an unusually thick region in the mantle transition zone at depths of about 410 to 660 km below the Earth's surface.
This zone separates the upper and lower mantle and expands or contracts depending on temperature.
The newly discovered ocean floor may also explain the unusual structure of the Pacific Large Low Shear Velocity Province (LLSVP), a huge region in Earth's lower mantle. Because LLSVP appears to be divided by slabs.
“This thickened area is like a fossil fingerprint of an ancient ocean floor that sank into the Earth about 250 million years ago,” Wang said.
“This gives us a glimpse into Earth's past that we've never seen before.”
Subduction occurs when one tectonic plate slides beneath another and surface material is recycled into the Earth's mantle.
This process often leaves behind visible evidence of movement, such as volcanoes, earthquakes, and deep ocean trenches.
Geologists, on the other hand, typically study subduction by examining rock samples and sediments found at the Earth's surface.
By studying how seismic waves travel through the different layers of the Earth, researchers were able to create a detailed map of the structures hidden deep within the mantle.
“You can think of seismic imaging as similar to a CT scan. Essentially, it allows us to see a cross-section of the Earth's interior,” Dr. Wang said. .
“Typically, chunks of ocean material are completely consumed by the Earth, leaving no discernible traces on the surface.”
“But looking at ancient subducted slabs through this perspective has provided new insights into the relationship between the Earth's very deep structures and surface geology that were not previously clear.”
What the authors discovered surprised them. Matter was moving much more slowly through the Earth's interior than previously thought.
The unusual thickness of this region they found suggests the presence of cold material in this part of the mantle transition zone, where parts of the oceanic slab become stuck in the middle as they sink through the mantle. It suggests that there is.
“We found that material is sinking at about half the rate expected in this region. This may be due to the mantle transition zone acting like a barrier, slowing the movement of material through the Earth. “This suggests something,” Dr. Wang said.
“Our findings raise new questions about how the deep Earth influences what we see at the surface over vast distances and time scales.”
of result Published in a magazine scientific progress.
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Wang Jingchuan others. 2024. Intraoceanic subduction during the Mesozoic era formed the lower mantle beneath the East Pacific uplift. scientific progress 10(39);doi: 10.1126/sciadv.ado1219
ohOne of the biggest changes in the modern video game industry is happening just beyond the reach of the average console gamer. Free-to-play gacha games, where you spend real money or in-game currency for a randomly selected set of characters and weapons, are booming in the Chinese market, led by publishers like miHoYo, NetEase, and Yostar. Some of the most popular games in this genre include Genshin, Arknights, and Another Eden, with tens of millions of players on smartphones and significant revenue from players willing to pay to enhance their collections.
More recently, the genre has expanded beyond mobile with Zenless Zone Zero, the newest addition. Developed by HoYoverse, the game is an expansive, anime-inspired action role-playing adventure set in a chaotic sci-fi dystopia. Earth has been invaded by extra-dimensional aliens, and human survivors now reside in New Eridu, a city built on the remains of a previous civilization. Players can choose to play as Wise or Bell, sibling hackers who run a video rental store, or as proxy agents sending teams of warriors on missions for clients.
Everything you do earns you some form of currency… Zenless Zone Zero. Photo: HoYoverse
Similar to the popular Persona RPG series, Zenless Zone Zero combines story, beat ’em up, and life simulation elements. Players navigate through various activities like fighting aliens, managing a video store, running errands, playing games, and capturing photographs of neighborhood cats. Actions in the game earn players currency, which can be used for upgrades and acquiring new characters. Completing contracts involves solving puzzles before battling aliens, leading to more lucrative missions and a continuous cycle.
Combat is straightforward with one button for attack and another for dodging. Characters have unique abilities and weapons, each with special and ultimate moves for enhanced gameplay. Switching between characters during combat adds visual effects and explosions, making it engaging.
Laser beams, bullets, blades flying…Zenless Zone Zero. Photo: HoYoverse
Visually, the game embodies cyberpunk anime with a rundown cityscape contrasted by advanced technology. Marauding gangs, AI raids, and cute robots coexist in a dystopian setting reminiscent of Studio Ghibli and Ghost in the Shell. The game allows for exploration of the environment, interactions with characters, and development of human relationships among the agents. The gacha system in the game entices players with rare items available for limited times, encouraging engagement through in-game currency or real money.
Zenless Zone Zero is a captivating gacha game with a mix of gameplay elements and a compelling narrative. Despite the controversial nature of gacha games, the experience offered by Zenless Zone Zero is engaging and rewarding, making it a fair exchange for players invested in its world.
LHS 1140b is the second-closest temperate transiting exoplanet to Earth, with temperatures cold enough for liquid water to exist on its surface.
LHS 1140b could be a completely icy world, like Jupiter's moon Europa (left), or it could be an icy world with a liquid ocean and cloud-like atmosphere (centre). Image courtesy of B. Gougeon / University of Montreal.
LHS 1140 is a cool, low-mass star located about 39 light-years from Earth in the constellation Cetus.
Also known as Gliese 3053, GJ 3053 and 2MASS J00445930-1516166, the star is about one-fifth the size of our Sun and is about 5 billion years old.
LHS 1140 is known to be home to three exoplanets: LHS 1140b, LHS 1140c, and LHS 1140d.
Earlier this year, astronomers reported new mass and radius estimates for LHS 1140b with extraordinary precision, matching estimates for the better-known TRAPPIST-1 planet: 1.7 times the size and 5.6 times the mass of Earth.
One of the key questions about LHS 1140b was whether it was a mini-Neptune-type exoplanet or a super-Earth.
The latter scenario included the possibility of the existence of so-called Hythean worlds with global liquid oceans enveloped in a hydrogen-rich atmosphere, which would show a clear atmospheric signal observable using Webb.
Analysis of Webb's new observations completely rules out the mini-Neptune scenario and provides compelling evidence suggesting that exoplanet LHS 1140b is a super-Earth, possibly with a nitrogen-rich atmosphere.
If confirmed, this result would make LHS 1140b the first temperate planet to show evidence of a secondary atmosphere that formed after the planet's initial formation.
Estimates based on all the accumulated data suggest that LHS 1140b is less dense than expected for a rocky planet with an Earth-like composition, and that 10-20% of its mass may be made up of water.
The discovery indicates that LHS 1140b is a fascinating watery world, possibly similar to a snowball or ice planet, and the planet's expected synchronous rotation means that a region of the planet's surface could always harbor a liquid ocean at its substellar point, facing the system's host star.
Artist's impression of planetary system LHS 1140. Image courtesy of Sci.News.
“Among the currently known temperate exoplanets, LHS 1140b may be the best candidate for future indirect confirmation of the existence of liquid water on the surface of an alien world outside our solar system,” said Charles Cadieux, a doctoral student at the University of Montreal.
“This will be a major milestone in the search for potentially habitable exoplanets.”
Although still preliminary, the presence of a nitrogen-rich atmosphere on LHS 1140b suggests that the planet could retain a significant amount of atmosphere, creating the conditions for liquid water to exist. This finding makes the water-world/snowball scenario the most plausible.
Current models suggest that if LHS 1140b had an Earth-like atmosphere, it would be a snowball planet with a huge bull's-eye shaped ocean about 4,000 km in diameter, equivalent to half the surface area of the Atlantic Ocean.
Surface temperatures in the core of this alien ocean could reach a comfortable 20 degrees Celsius.
LHS 1140b has favorable conditions for a potential atmosphere and liquid water, making it an excellent candidate for future habitability studies.
“The planet provides a unique opportunity to study worlds that could potentially support life, as it is located in the habitable zone of its star and likely has an atmosphere capable of retaining heat and supporting a stable climate,” the astronomers said.
Using data from NASA’s Transiting Exoplanet Survey Satellite (TESS), astronomers discovered a habitable zone planet orbiting nearby red dwarf star TOI-715 every 19.3 days and characterized its characteristics. I made it clear. They also demonstrated that a second, smaller exoplanet with a period of 25.6 days may exist, located just inside the outer edge of TOI-715’s habitable zone. This system represents the first of his TESS discoveries to fall within this most conservative and widely applicable habitable zone.
Artist’s impression of the super-Earth exoplanet TOI-715b. Image credit: NASA/JPL-Caltech.
TOI-715 is an M dwarf star of spectral type M4 located approximately 137 light-years away in the constellation Urae.
The star, also known as TIC 271971130, is about 6.6 billion years old, making it older than the Sun.
TOI-715 includes the super-Earth exoplanet TOI-715b and the smaller terrestrial exoplanet candidate TOI-715c.
“TOI-715b is about 1.5 times wider than Earth and orbits within the habitable zone around its parent star,” said Georgina Dransfield, an astronomer at the University of Birmingham.
“This is the distance from the star that can give the planet the right temperature for liquid water to form on its surface.”
“Of course, for surface water to exist, several other factors have to be in place, especially for us to have a suitable atmosphere.”
“However, the conservative habitable zone (which may be narrower and more robustly defined than the broader ‘optimistic’ habitable zone) is a It ranks first.”
“A smaller planet, TOI-715c, may be only slightly larger than Earth and may exist just inside the conservative habitable zone.”
“TOI-175b joins the list of habitable zone planets that could be scrutinized more closely by Webb, perhaps also for atmospheric signatures,” the astronomers said.
“A lot depends on other properties of the planet, such as how heavy it is and whether it can be classified as a water world. Its atmosphere, if any at all, is more massive, denser, and has an atmosphere. It’s less pronounced than the atmosphere, and much less difficult to detect. Drier worlds are likely to keep their inconspicuous atmospheres close to the surface.”
“If the possibility of a second Earth-sized planet in this system is confirmed, it would be the smallest habitable zone planet ever discovered by TESS.”
“This discovery also exceeds TESS’s initial expectations by discovering an Earth-sized world within the habitable zone.”
This finding is reported in the following article: paper inside Royal Astronomical Society Monthly Notices.
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Georgina Dransfield other. 2024. Earth's habitable zone planet hosted by the M4 star TOI-715 near the ecliptic south pole. MNRAS 527 (1): 35-52; doi: 10.1093/mnras/stad1439
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