Author: admin

  • Gravity-sensitive Spectral Indices In Ultracool Dwarfs: Investigating Correlations With Metallicity And Planet Occurrence Using SpeX and FIRE Observations

    Gravity-sensitive Spectral Indices In Ultracool Dwarfs: Investigating Correlations With Metallicity And Planet Occurrence Using SpeX and FIRE Observations

    EWs for the K i lines in the J band vs. NIR spectral type for M dwarfs in our sample. The figure elements are the same as in Figure 3. The panels display: (a) NIR spectral type vs. K i 1.169 µm EW, (b) NIR spectral type vs. K i 1.177 µm EW, and (c) NIR spectral type vs. K i 1.253 µm EW. — astro-ph.EP

    We present a near-infrared spectroscopic analysis (0.9-2.4 micron) of gravity indices for 57 ultracool dwarfs (spectral types M5.5 to L0), including exoplanet hosts TRAPPIST-1, SPECULOOS-2, SPECULOOS-3, and LHS 3154. Our dataset includes 61 spectra from the SpeX and FIRE spectrographs.

    Using gravity-sensitive indices such as FeH absorption (at 0.99, 1.20, and 1.55 microns), the VO band at 1.06 microns, the H-band continuum, and alkali lines like K I (at 1.17 and 1.25 microns), we investigate correlations between surface gravity, stellar metallicity, and the presence of close-in transiting planets.

    All four planet-hosting stars show intermediate-gravity spectral signatures despite indicators of field age. However, a volume-corrected logistic regression reveals no significant association between gravity class and planet occurrence. Among individual indices, FeH_z is the most promising tracer of planet-hosting status.

    We tentatively identify a correlation between FeH_z (0.99 micron) and planet presence at the 2-sigma level, though this may reflect observational biases including transit probability, small-number statistics, and detection sensitivity. More robustly, we find a significant anti-correlation between FeH_z and metallicity ([Fe/H]) at 3.3 sigma. A Kruskal-Wallis test shows no significant metallicity difference across gravity classes, suggesting the observed FeH_z-metallicity trend is not driven by bulk metallicity differences.

    We propose this anti-correlation reflects interplay between age, gravity, and composition: higher-metallicity objects may be systematically younger with lower gravities, suppressing FeH absorption. While our results only hint at a link between gravity-related characteristics and planet occurrence among late-M dwarfs, they underscore the need for caution when using spectral diagnostics to infer properties of planet-hosting ultracool dwarfs.

    Fatemeh Davoudi, Benjamin V. Rackham, Julien de Wit, Jan Toomlaid, Michaël Gillon, Amaury H. M. J. Triaud, Adam J. Burgasser, Christopher A. Theissen

    Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
    Cite as: arXiv:2506.19928 [astro-ph.EP] (or arXiv:2506.19928v1 [astro-ph.EP] for this version)
    https://doi.org/10.48550/arXiv.2506.19928
    Focus to learn more
    Submission history
    From: Fatemeh Davoudi
    [v1] Tue, 24 Jun 2025 18:05:48 UTC (2,086 KB)
    https://arxiv.org/abs/2506.19928
    Astrobiology

    Continue Reading

  • Astronomers discover ‘raw materials for life’ can form in planetary systems even before stars

    Astronomers discover ‘raw materials for life’ can form in planetary systems even before stars

    Scientists are claiming a “cosmic chemistry breakthrough” following the discovery of a large “aromatic” molecule in deep space. The discovery suggests that these molecules could help seed planetary systems with carbon, supporting the development of molecules needed for life.

    The molecule, called cyanocoronene, belongs to a class of carbon-based organic compounds called polycyclic aromatic hydrocarbons (PAHs), which are made up of multiple fused aromatic rings — structures in which electrons are shared across double-bonded carbon atoms, giving them unique chemical stability.

    Continue Reading

  • Page not found – National Radio Astronomy Observatory

    Page not found – National Radio Astronomy Observatory

    The National Radio Astronomy Observatory is a facility of the U.S. National Science Foundation
    operated under cooperative agreement by Associated Universities, Inc. Founded in 1956, the NRAO provides state-of-the-art radio telescope facilities for use by the international scientific community. NRAO telescopes are open to all astronomers regardless of institutional or national affiliation. Observing time on NRAO telescopes is available on a competitive basis to qualified scientists after evaluation of research proposals on the basis of scientific merit, the capability of the instruments to do the work, and the availability of the telescope during the requested time. NRAO also provides both formal and informal programs in education and public outreach for teachers, students, the general public, and the media.

    The U.S. National Science Foundation (NSF) is an independent federal agency created by Congress in 1950 “to promote the progress of science; to advance the national health, prosperity, and welfare; to secure the national defense…”

    AUI collaborates with the scientific community and research sponsors to plan, build, and operate cutting-edge facilities. We cultivate excellence, deliver value, enhance education, and engage the public.

    Continue Reading

  • Heat Wave Triggers Health Alerts in Europe – Bloomberg.com

    1. Heat Wave Triggers Health Alerts in Europe  Bloomberg.com
    2. ‘Unprecedented’ alerts in France as blistering heat grips Europe  BBC
    3. Thousands flee wildfires in Turkiye as Europe is hit by early heatwave  Dawn
    4. Europe swelters as early summer heat breaks records  dw.com
    5. Southern Europe roasts as temperatures soar  nation.com.pk

    Continue Reading

  • Elden Ring Switch 2 Could Be Releasing Sooner Than Expected

    Elden Ring Switch 2 Could Be Releasing Sooner Than Expected

    Elden Ring Tarnished Edition has recently been rated by the Entertainment Software Rating Board. With the ESRB finalizing its review of the game, it could mean the Elden Ring Switch 2 edition could be launching sooner than some expected.

    ‘Elden Ring’ Switch 2 Release Date Could be hinted at with ESRB Rating completed

    Screenshot: FromSoftware, Nintendo

    Although Elden Ring Tarnished Edition was initially revealed during the Switch 2 Direct in April, no release date was given at the time. However, the popular FromSoftware RPG was recently rated by the ESRB for Nintendo’s console on June 30. This could actually give us an idea when we can expect the much-anticipated port.

    Once a title is rated by ESRB, they sometimes release 4 to 6 months after it. “Sometimes” being the important keyword here, as this isn’t always the case. But it’s true for a lot of games. With FromSoftware stating that Elden Ring Switch 2 was set to launch “sometime in 2025”, it could launch on Switch 2 anytime between August through December. So while there is no guarantee, it looks like the game isn’t going to be delayed into 2026, as some fans had worried.

    'Elden Ring' Switch 2 ESRB Rating
    Screenshot: ESRB

    As a side note, I can’t help but be amused reading ESRB’s rating of Elden Ring Switch 2 edition. “ELDEN RING Tarnished Edition is rated M for Mature 17+ by the ESRB with Blood and Gore, Language, Suggestive Themes, and Violence. During the course of the game, a humanoid monster is depicted partially nude, with scales/scars covering its breast and pelvic regions. The word “sh*t” appears in the dialogue.” I sometimes forget how weird Elden Ring gets. The fact that we can play it on a Nintendo console is just kind of mind-blowing, as a 90s kid.

    'Elden Ring' Story Trailer
    Screenshot: FromSoftware

    With a Nintendo Switch 2 Direct rumored to be happening in July, some have theorized that the release date for Elden Ring Tarnished Edition could be announced then. Although the “leaked” Direct also claims a Metaphor: ReFantazio port is also going to be revealed at the event. Maybe it’s just me, but this is starting to sound a little too good to be true. But hey, you never know!

    Another thing I’m curious about is how Elden Ring will actually perform on Switch 2. There is no way that it actually runs at 60 FPS, as it struggles to maintain that on PS5. But if FromSoftware is able to keep it locked at 30 FPS with decent graphics, it could be the best way to play the open-world RPG on the go. I’ve actually beaten the game on my Asus ROG, and it’s far from perfect.

    FromSoftware is teaming up with Nintendo again, with the release of The Duskbloods. The exclusive multiplayer is scheduled to launch sometime in 2026. So Elden Ring releasing in 2025 would be a good warm-up for players diving into FromSoftware for the first time. Then again, you can play Dark Souls right now on Nintendo Switch 2. Even if it doesn’t have an upgraded version, it still runs decently!


    Continue Reading

  • Fonseca flies past Fearnley on Wimbledon debut – ATP Tour

    1. Fonseca flies past Fearnley on Wimbledon debut  ATP Tour
    2. ‘I know everything is possible’: Teenager João Fonseca on Wimbledon, football and Federer  The Guardian
    3. ATP Wimbledon Best Bets Including Fonseca vs Fearnley  Last Word On Sports
    4. Fonseca expects Brazilian fans to bring the noise at Wimbledon  France 24
    5. Joao Fonseca Says He’s Adapting to the Unpredictability of the ATP Ahead of Wimbledon  MSN

    Continue Reading

  • Saltier, hotter & fast losing ice: Dramatic shift for Southern Ocean

    Saltier, hotter & fast losing ice: Dramatic shift for Southern Ocean

    In these polar waters, cold, fresh surface water overlays warmer, saltier waters from the deep. In the winter, as the surface cools and sea ice forms, the density difference between water layers weakens, allowing these layers to mix and heat to be transported upward, melting the sea ice from below and limiting its growth.

    Since the early 1980s, the surface of the Southern Ocean had been freshening, and stratification – that density difference between the water layers – had been strengthening. This was trapping heat below and sustaining more sea ice coverage.

    Now, new satellite technology, combined with information from floating robotic devices which travel up and down the water column, shows this trend has reversed; surface salinity is increasing, stratification is weakening, and sea ice has reached multiple record lows – with large openings of open ocean in the sea ice (polynyas) returning.

    This is the first time scientists have been able to monitor these changes in the Southern Ocean in real time. 

    Aditya Narayanan, a postdoctoral research fellow at the University of Southampton and co-author on the paper, said: “While scientists expected that human-driven climate change would eventually lead to Antarctic Sea ice decline, the timing and nature of this shift remained uncertain.

    “Previous projections emphasised enhanced surface freshening and stronger ocean stratification, which could have supported sustained sea ice cover. Instead, a rapid reduction in sea ice – an important reflector of solar radiation – has occurred, potentially accelerating global warming.”

    What this all means is that – according to Professor Alberto Naveira Garabato, co-author on the study and Regius Professor of Ocean Sciences at the University of Southampton – our current understanding “may be insufficient” to accurately predict future changes.

    “It makes the need for continuous satellite and in-situ monitoring all the more pressing, so we can better understand the drivers of recent and future shifts in the ice-ocean system.”

    The paper – ‘Rising surface salinity and declining sea ice: a new Southern Ocean state revealed by satellites is published in Proceedings of the National Academy of Sciences and is available online.

    This project has been supported by the European Space Agency.

    Click here for more from the Oceanographic Newsroom.


    Continue Reading

  • Athlete Refugee Team: Seyd Taha Ghafari’s journey | News | Athletics Better World

    Athlete Refugee Team: Seyd Taha Ghafari’s journey | News | Athletics Better World


    This feature is the second in a five-part series sharing the stories of refugee athletes Farida Abaroge, Seyd Taha Ghafari, Omar Hassan, Emmanuel Kiruhura Ntagunga and Seyfu Jamaal Tahir as they seek selection to the Athlete Refugee Team (ART) at the World Athletics Championships Tokyo 25. 

     

    After taking on work that put his life in danger, Seyd Taha Ghafari was forced to flee Iran, leaving everything he knew behind. 

    Ghafari was unable to see his family for five long years. When he arrived in the UK with no certainties, he found strength and connection through running. 

    Running became his lifeline, helping him to navigate a new world, build a community and regain hope.

    “I continued to run, because it gives you good feeling – mentally and physically,” explains the 30-year-old, who ran for the Athlete Refugee Team at the World Athletics Cross Country Championships in Bathurst in 2023.

    “I saw my family briefly. That was a very sad moment. You don’t only leave your family, you leave your friends and everything you’ve built, just like that.

    “A big motivation for me when I arrived was that I saw so many people running in the parks and on the roads in the UK. I felt really good. I felt like I knew all of them. I started running again and it felt like home.

    “As marathon runners, we have lots of long runs. Many things in your mind come and go. I’m always thinking about my past, and what a great opportunity I have.”

    View the full video feature on World Athletics Watch.

     

    Video features on Farida Abaroge, Emmanuel Kiruhura Ntagunga and Seyfu Jamaal Tahir will be published on World Athletics Watch during the next few weeks. The feature on Omar Hassan is already available.

    Interview and video production by Christel Saneh for World Athletics

     

    Continue Reading

  • Xbox Needs to Get Weirder or Die Trying

    Xbox Needs to Get Weirder or Die Trying

    Xbox is in a weird place right now, and I’m not the only one who thinks so. In fact, people with more important opinions on the subject than myself seem to agree: if Microsoft doesn’t get its shit together on hardware, the box as we know it is cooked. Laura Fryer, the former director of the Xbox Advanced Technology Group for the original Xbox project back in May 2000 and former executive producer for Microsoft Games Studios up until the Xbox 360 days, put it bluntly in a recent video.

    “Obviously, as one of the founding members of the Xbox team, I’m not pleased with where things are today. I don’t love watching all of the value that I helped create slowly get eroded away,” Fryer said in a video on YouTube. “I’m sad because, from my perspective, it looks like Xbox has no desire—or literally can’t—ship hardware anymore. So, this partnership is about a slow exit from the hardware business completely. Personally, I think Xbox hardware is dead.”

    The partnership that Fryer is referring to is, of course, the Xbox and Asus team-up that will see the release of the ROG Xbox Ally handheld that was announced at Computex earlier this month. The criticism from within the games industry and fans is that Microsoft didn’t design the handheld device, instead outsourcing the work to Asus, which modified its existing ROG Ally X handheld PCs, and then slapped Xbox software onto it. Was it laziness on Microsoft and Xbox’s part? Or is it afraid to commit to Xbox hardware?

    Ouch. As rough as those words may be, it’s hard not to agree. Out of the gate, Xbox’s current generation of consoles, the Series S and X, were all but trounced by Sony and the PS5, the latter of which snatched a commanding 70 percent of the market share in the first five years of both consoles’ lives. There are a lot of reasons for that, and arguably the biggest is that PlayStation had the exclusive titles that made people actually want to buy a console. But pinning it on game exclusives doesn’t paint the full picture. Part of the problem is that Xbox, for all its past Gamer with a capital “G” glory, got boring. So yes, Xbox is in a weird place right now, but people still want consoles, which means it’s time for them to get even weirder—yes, I’m talking hardware, too.

    First, let’s start with the boring box that Xbox houses all of that X in. It sucks. It’s a snooze that makes year-over-year smartphone design feel innovative. Sure, it’s sterile and can mesh with your new-build city-dwelling decor, but it’s also—on the downside—half-assed. If you’re selling people hardware that plays games, they ought to know that it’s a console and not a VCR you forgot to sell in 1997. Say what you will about the PS5 (it’s ugly; that’s the only correct opinion), but Sony took a swing with it. It made sure that everyone who bought one felt like they were buying a console, and like it or not, you eat with your eyes. If you want to give people a reason to buy your console, maybe try giving them a reason. Nintendo did that with the Switch in 2017, and as far as I can tell, that’s going (checks watch) really f*cking well.

    Speaking of the Switch, Xbox should probably find a way to differentiate its hardware functionality-wise. As dominant as the PS5 has been in the console business, it’s still fundamentally the same machine as the Xbox. That’s a shame, considering Xbox had ample opportunities to bring hardware in exciting new directions over the years. Not to be the Kinect guy, but damn did Microsoft bungle XR big time—and then again, it bungled XR with the HoloLens. In the multiverse, there’s a timeline where Xbox used its experiments with XR via the Kinect and HoloLens to snatch value from the trembling hands of Sony and Meta’s Quest headsets. That is not this timeline, as we all know, but if it really wants to give Xbox a future worth financing, maybe there’s still room to take those more daring expeditions into gaming and refresh them for today’s age.

    © Adriano Contreras / Gizmodo

    The last thing Xbox needs to do to get weird is a little more nebulous—it needs a new identity. Sure, Game Pass has been a ray of light in an otherwise dim outlook for Xbox, but turning the consoles into subscription machines doesn’t exactly scream, “We see you gamers, and we hear you.” Xbox can still continue to sell Game Pass subscriptions, don’t get me wrong—I love Game Pass, and being able to stream games on devices like the Quest 3 feels like a revelation to me. But the emphasis on Xbox being the thing that gets you to the thing makes hardware feel like an afterthought. Gaming on a console that you’ve spent $500 on should feel native; it should feel complete; it should feel like an Xbox, not a PC. That goes back to game exclusives, partly. Sony has had no issues getting weird with its exclusives—Death Stranding, for example, is one of the weirdest games you can play, and now Death Stranding 2 is a PS5 exclusive, which is apparently devastating some gamers. Sucks for them, but it’s kind of a huge win for PlayStation. It’s also more proof that Xbox doesn’t need to be the Netflix of gaming; it needs weird, magnetic titles that make its console feel experiential.

    As you may have gathered, this would all be kind of a huge shift for Xbox, and it’s debatable whether Microsoft even has the will to make any of it work. I know the last few years have been lackluster for Xbox, but people still want consoles, and the recent success of the Switch 2 all but proves that. Nintendo, for its part, didn’t earn that success the easy way. It took a gamble with the Switch by redefining its hardware, pivoting inward towards games, and ended up releasing the defining console of our generation. That’s all to say, the ball is in your court, Microsoft. Are you going to go out with a bland, forgettable box? Or get weird and, at the very least, go down swinging?

    Continue Reading

  • Life At The Extremes: Maximally Divergent Microbes With Similar Genomic Signatures Linked To Extreme Environments

    Life At The Extremes: Maximally Divergent Microbes With Similar Genomic Signatures Linked To Extreme Environments

    Multi-layered pipeline for identifying bacterium/archaeon pairs with similar genomic signatures. Layer 1: Five selected non-parametric clustering methods identify clusters of organisms with similar genomic signatures. The clusters containing both bacteria and archaea (green) generate a list of 78 candidate bacterium–archaeon pairs, grouped by these algorithms based on their similar genomic signatures. Layer 2-a:: The candidate pairs from Layer 1 undergo pairwise distance calculations between their FCGRs using four different distance metrics. Only 40 pairs, with the majority of distances below empirically determined thresholds, are retained. Layer 2-b: In parallel to FCGR comparison, a biological analysis is conducted on the output pairs from Layer 1. This includes checking environment labels and examining metadata about their living environments to select pairs isolated from similar types of extreme environments, resulting in 20 pairs. The final output is a list of 15 bacterium/archaeon pairs (comprising 16 unique genera and 20 unique species) that passed all filtering layers. These pairs can confidently be proposed as maximally divergent microbes that share similar genomic signatures associated with their living environments. — biorxiv.org

    Extreme environments impose strong mutation and selection pressures that drive distinctive, yet understudied, genomic adaptations in extremophiles.

    In this study, we identify 15 bacterium–archaeon pairs that exhibit highly similar k-mer–based genomic signatures despite maximal taxonomic divergence, suggesting that shared environmental conditions can produce convergent, genome-wide patterns that transcend evolutionary distance. To uncover these patterns, we developed a computational pipeline to select a composite genome proxy assembled from non-contiguous subsequences of the genome.

    Using supervised machine learning on a curated dataset of 693 extremophile microbial genomes, we found that 6-mers and 100 kbp genome proxy lengths provide the best balance between classification accuracy and computational efficiency. Our results provide conclusive evidence of the pervasive nature of k-mer–based patterns across the genome, and uncover the presence of taxonomic and environmental components that persist across all regions of the genome.

    The 15 bacterium-archaeon pairs identified by our method as having similar genomic signatures were validated through multiple independent analyses, including 3-mer frequency profile comparisons, phenotypic trait similarity, and geographic co-occurrence data. These complementary validations confirmed that extreme environmental pressures can override traditionally recognized taxonomic components at the whole-genome level.

    Together, these findings reveal that adaptation to extreme conditions can carry robust, taxonomic domain-spanning imprints on microbial genomes, offering new insight into the relationship between environmental mutagenesis and selection and genome-wide evolutionary convergence.

    Life at the extremes: Maximally divergent microbes with similar genomic signatures linked to extreme environments, biorxiv.org

    Astrobiology

    Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

    Continue Reading