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earth's surface is composed of a staggering diversity of particulate-fluid mixtures: dry to wet, dilute to dense, colloidal to granular and attractive to repulsive particles. this material variety is matched by the range of relevant stresses and strain rates, from laminar to turbulent flows and steady to intermittent f... | viewing earth's surface as a soft-matter landscape |
planktonic organisms play crucial roles in oceanic food webs and global biogeochemical cycles. most of our knowledge about the ecological impact of large zooplankton stems from research on abundant and robust crustaceans, and in particular copepods. a number of the other organisms that comprise planktonic communities a... | in situ imaging reveals the biomass of giant protists in the global ocean |
tropical forests concentrate the largest diversity of species on the planet and play a key role in maintaining environmental processes. due to the importance of those forests, there is growing interest in mapping their components and getting information at an individual tree level to conduct reliable satellite-based fo... | tree crown delineation algorithm based on a convolutional neural network |
the gravity harmonics of a fluid, rotating planet can be decomposed into static components arising from solid-body rotation and dynamic components arising from flows. in the absence of internal dynamics, the gravity field is axially and hemispherically symmetric and is dominated by even zonal gravity harmonics j2n that... | measurement of jupiter’s asymmetric gravity field |
air quality in china has been gradually improving because of recent emission control policies, but synoptic circulations in the planetary boundary layer have become increasingly conducive to haze formation. the effect of persistent synoptic circulation (psc) on long-term variation in haze episodes remains to be fully e... | long-term trends of persistent synoptic circulation events in planetary boundary layer and their relationships with haze pollution in winter half year over eastern china |
accurate and continuous measurements of soil thermal and hydraulic properties are required for environmental, earth and planetary science, and engineering applications, but they are not practically obtained by steady-state methods. the heat pulse (hp) method is a transient method for determination of soil thermal prope... | development and application of the heat pulse method for soil physical measurements |
little is known about the origin of the spectral diversity of asteroids and what it says about conditions in the protoplanetary disk. here, we show that samples returned from cb-type asteroid ryugu have fe isotopic anomalies indistinguishable from ivuna-type (ci) chondrites, which are distinct from all other carbonaceo... | ryugu's nucleosynthetic heritage from the outskirts of the solar system |
the surfaces of rocky planets are mostly covered by basaltic crust, but earth is unique in that it also has extensive regions of felsic crust, manifested in the form of continents. exactly how felsic crust forms when basaltic magmas are the dominant products of melting the mantles of rocky planets is unclear. a fundame... | nb/ta systematics in arc magma differentiation and the role of arclogites in continent formation |
we present 3d hydrodynamical models of the hd 142527 protoplanetary disc, a bright and well-studied disc that shows spirals and shadows in scattered light around a 100 au gas cavity, a large horseshoe dust structure in mm continuum emission, together with mysterious fast radial flows and streamers seen in gas kinematic... | circumbinary, not transitional: on the spiral arms, cavity, shadows, fast radial flows, streamers, and horseshoe in the hd 142527 disc |
all-sky photometric time-series missions have allowed for the monitoring of thousands of young (tage < 800 myr) stars in order to understand the evolution of stellar activity. here, we developed a convolutional neural network (cnn), stella, specifically trained to find flares in transiting exoplanet survey satellite... | flare statistics for young stars from a convolutional neural network analysis of tess data |
we present 197 planet candidates discovered using data from the first year of the nasa k2 mission (campaigns 0-4), along with the results of an intensive program of photometric analyses, stellar spectroscopy, high-resolution imaging, and statistical validation. we distill these candidates into sets of 104 validated pla... | 197 candidates and 104 validated planets in k2’s first five fields |
the kepler space telescope is currently searching for planets transiting stars along the ecliptic plane as part of its extended k2 mission. we processed the publicly released data from the first year of k2 observations (campaigns 0, 1, 2, and 3) and searched for periodic eclipse signals consistent with planetary transi... | planetary candidates from the first year of the k2 mission |
gaps in protoplanetary disks have long been hailed as signposts of planet formation. however, a direct link between exoplanets and disks remains hard to identify. we present a large sample study of alma disk surveys of nearby star-forming regions to disentangle this connection. all disks are classified as either struct... | a stellar mass dependence of structured disks: a possible link with exoplanet demographics |
a critical step toward the emergence of planets in a protoplanetary disk is the accretion of planetesimals, bodies 1-1,000 km in size, from smaller disk constituents. this process is poorly understood, partly because we lack good observational constraints on the complex physical processes that contribute to planetesima... | trans-neptunian binaries as evidence for planetesimal formation by the streaming instability |
jupiter’s atmosphere is rotating differentially, with zones and belts rotating at speeds that differ by up to 100 metres per second. whether this is also true of the gas giant’s interior has been unknown, limiting our ability to probe the structure and composition of the planet. the discovery by the juno spacecraft tha... | a suppression of differential rotation in jupiter’s deep interior |
few traces of earth's geologic record are preserved from the time of life's emergence, over 3,800 million years ago. consequently, what little we understand about abiogenesis — the origin of life on earth — is based primarily on laboratory experiments and theory. the best geological lens for understanding early earth m... | the martian subsurface as a potential window into the origin of life |
exoplanet hunting efforts have revealed the prevalence of exotic worlds with diverse properties, including earth-sized bodies, which has fueled our endeavor to search for life beyond the solar system. accumulating experiences in astrophysical, chemical, and climatological characterization of uninhabitable planets are p... | exoplanet biosignatures: observational prospects |
the discovery of only a handful of exoplanets required establishing a correlation between giant planet occurrence and metallicity of their host stars. more than 20 years have already passed from that discovery, however, many questions are still under lively debate: (1) what is the origin of that relation?; (2) what is ... | heavy metal rules. i. exoplanet incidence and metallicity |
the nearly circular (mean eccentricity e¯≈0.06) and coplanar (mean mutual inclination i¯≈3°) orbits of the solar system planets motivated kant and laplace to hypothesize that planets are formed in disks, which has developed into the widely accepted theory of planet formation. the first several hundred extrasolar planet... | exoplanet orbital eccentricities derived from lamost-kepler analysis |
using 3d global hydro simulations coupled with radiative transfer calculations, we study the appearance of density waves induced by giant planets in direct imaging observations at near-infrared wavelengths. we find that a 6{m}{{j}} planet in a typical disk around a 1{m}⊙star can produce prominent and detectable spiral ... | observational signatures of planets in protoplanetary disks: spiral arms observed in scattered light imaging can be induced by planets |
understanding planet formation requires one to discern how dust grows in protoplanetary disks. an important parameter to measure in disks is the maximum dust grain size present. this is usually estimated through measurements of the dust opacity at different millimeter wavelengths assuming optically thin emission and du... | the radial distribution of dust particles in the hl tau disk from alma and vla observations |
aims: we report on espresso high-resolution transmission spectroscopic observations of two primary transits of the highly irradiated, ultra-hot jupiter-sized planet, wasp-76b. we investigated the presence of several key atomic and molecular features of interest that may reveal the atmospheric properties of the planet.m... | espresso high-resolution transmission spectroscopy of wasp-76 b |
planets intermediate in size between the earth and neptune, and orbiting closer to their host stars than mercury does the sun, are the most common type of planet revealed by exoplanet surveys over the last quarter century. results from nasa's kepler mission have revealed a bimodality in the radius distribution of these... | the nature and origins of sub-neptune size planets |
the population of planets smaller than approximately 1.7 earth radii (r⊕) is widely interpreted as consisting of rocky worlds, generally referred to as super-earths. this picture is largely corroborated by radial velocity mass measurements for close-in super-earths but lacks constraints at lower insolations. here we pr... | evidence for the volatile-rich composition of a 1.5-earth-radius planet |
water ice is abundant in protoplanetary disks. its sticking properties are therefore important during phases of collisional growth. in this work, we study the sticking and rolling of 1.1 mm ice grains at different temperatures. we find a strong increase in sticking between 175 and 200 k, which levels off at higher temp... | contacts of water ice in protoplanetary disks—laboratory experiments |
marine low clouds strongly cool the planet. how this cooling effect will respond to climate change is a leading source of uncertainty in climate sensitivity, the planetary warming resulting from co2 doubling. here, we observationally constrain this low cloud feedback at a near-global scale. satellite observations are u... | observational constraints on low cloud feedback reduce uncertainty of climate sensitivity |
saturn is orbited by dozens of moons, and the intricate dynamics of this complex system provide clues about its formation and evolution. tidal friction within saturn causes its moons to migrate outwards, driving them into orbital resonances that pump their eccentricities or inclinations, which in turn leads to tidal he... | resonance locking in giant planets indicated by the rapid orbital expansion of titan |
five decades of observations of ceres suggest that the dwarf planet has a composition similar to carbonaceous meteorites and may have an ice-rich outer shell protected by a silicate layer. nasa's dawn spacecraft has detected ubiquitous clays, carbonates and other products of aqueous alteration across the surface of cer... | geomorphological evidence for ground ice on dwarf planet ceres |
mars science laboratory curiosity rover observations of the 2018/mars year 34 global/planet-encircling dust storm represent the first in situ measurements of a global dust storm with dedicated meteorological sensors since the viking landers. the mars science laboratory team planned and executed a science campaign lasti... | mars science laboratory observations of the 2018/mars year 34 global dust storm |
we report results from global ideal mhd simulations that study thin accretion disks (with thermal scale height h/r = 0.1 and 0.05) threaded by net vertical magnetic fields. our computations span three orders of magnitude in radius, extend all the way to the pole, and are evolved for more than 1000 innermost orbits. we ... | global evolution of an accretion disk with a net vertical field: coronal accretion, flux transport, and disk winds |
general relativity1 predicts that short-orbital-period binaries emit considerable amounts of gravitational radiation. the upcoming laser interferometer space antenna2 (lisa) is expected to detect tens of thousands of such systems3 but few have been identified4, of which only one5 is eclipsing—the double-white-dwarf bin... | general relativistic orbital decay in a seven-minute-orbital-period eclipsing binary system |
the lunar surface electromagnetics explorer 'lusee night' is a low frequency radio astronomy experiment that will be delivered to the farside of the moon by the nasa commercial lunar payload services (clps) program in late 2025 or early 2026. the payload system is being developed jointly by nasa and the us department o... | lusee 'night': the lunar surface electromagnetics experiment |
astrophysicists are increasingly taking into account the effects of orbiting companions on stellar evolution. new discoveries have underlined the role of binary star interactions in a range of astrophysical events, including some that were previously interpreted as being due uniquely to single stellar evolution. we rev... | dawes review 6: the impact of companions on stellar evolution |
trappist-1 planets are invaluable for the study of comparative planetary science outside our solar system and possibly habitability. both transit timing variations (ttv) of the planets and the compact, resonant architecture of the system suggest that trappist-1 planets could be endowed with various volatiles today. fir... | modeling climate diversity, tidal dynamics and the fate of volatiles on trappist-1 planets |
we report the discovery of 9088 new spectroscopically confirmed white dwarfs and subdwarfs in the sloan digital sky survey data release 10. we obtain teff, log g and mass for hydrogen atmosphere white dwarf stars (das) and helium atmosphere white dwarf stars (dbs), and estimate the calcium/helium abundances for the whi... | new white dwarf stars in the sloan digital sky survey data release 10 |
the kepler spacecraft has discovered a large number of planets with up to one-year periods and down to terrestrial sizes. while the majority of the target stars are main-sequence dwarfs of spectral type f, g, and k, kepler covers stars with effective temperatures as low as 2500 k, which corresponds to m stars. these co... | a stellar-mass-dependent drop in planet occurrence rates |
the evidence for abundant liquid water on early mars despite the faint young sun is a long-standing problem in planetary research. here we present new ab initio spectroscopic and line-by-line climate calculations of the warming potential of reduced atmospheres on early mars. we show that the strength of both co2-h2 and... | transient reducing greenhouse warming on early mars |
atmospheric co2 levels and global climate are regulated on geological timescales by the silicate weathering feedback. however, this thermostat has failed multiple times in earth's history, most spectacularly during the cryogenian (c. 720-635 ma) snowball earth episodes. the unique middle neoproterozoic paleogeography o... | continental flood basalt weathering as a trigger for neoproterozoic snowball earth |
the tundra plays a pivotal role in the arctic mercury (hg) cycle by storing atmospheric hg deposition and shuttling it to the arctic ocean. a recent study revealed that 70 % of the atmospheric hg deposition to the tundra occurs through gaseous elemental mercury (gem or hg(0)) uptake by vegetation and soils. processes c... | insights from mercury stable isotopes on terrestrial-atmosphere exchange of hg(0) in the arctic tundra |
northwestern alaska has been highly affected by changing climatic patterns with new temperature and precipitation maxima over the recent years. in particular, the baldwin and northern seward peninsulas are characterized by an abundance of thermokarst lakes that are highly dynamic and prone to lake drainage like many ot... | the catastrophic thermokarst lake drainage events of 2018 in northwestern alaska: fast-forward into the future |
understanding how geography, oceanography, and climate have ultimately shaped marine biodiversity requires aligning the distributions of genetic diversity across multiple taxa. here, we examine phylogeographic partitions in the sea against a backdrop of biogeographic provinces defined by taxonomy, endemism, and species... | comparative phylogeography of the ocean planet |
accurate measurements of the physical structure of protoplanetary discs are critical inputs for planet formation models. these constraints are traditionally established via complex modelling of continuum and line observations. instead, we present an empirical framework to locate the co isotopologue emitting surfaces fr... | direct mapping of the temperature and velocity gradients in discs. imaging the vertical co snow line around im lupi |
this study unifies quantitative methods with dated molecular phylogenies of different lineages to identify biogeographical regions and understand the spatial and temporal evolution of the biota in one of the most biodiverse hotspots of the planet, the tropical andes. we found complex distribution patterns reflected in ... | biogeographic regions and events of isolation and diversification of the endemic biota of the tropical andes |
air quality forecast systems need reliable and accurate representations of the planetary boundary layer (pbl) to perform well. an important question is how accurately numerical weather prediction models can reproduce conditions in diverse synoptic flow types. here, observations from the summer 2014 hygra-cd (hygroscopi... | sensitivity of boundary-layer variables to pbl schemes in the wrf model based on surface meteorological observations, lidar, and radiosondes during the hygra-cd campaign |
observations of comets and asteroids show that the solar nebula that spawned our planetary system was rich in water and organic molecules. bombardment brought these organics to the young earth's surface. unlike asteroids, comets preserve a nearly pristine record of the solar nebula composition. the presence of cyanides... | the comet-like composition of a protoplanetary disk as revealed by complex cyanides |
we present atmospheric measurements of methane (ch4) and ethane (c2h6) taken aboard a national oceanic and atmospheric administration wp-3d research aircraft in 2015 over oil- and natural gas-producing regions of the central and western united states. we calculate emission rates from the horizontal flux of ch4 and c2h6... | quantifying methane and ethane emissions to the atmosphere from central and western u.s. oil and natural gas production regions |
the earth-moon system has unique chemical and isotopic signatures compared with other planetary bodies; any successful model for the origin of this system therefore has to satisfy these chemical and isotopic constraints. the moon is substantially depleted in volatile elements such as potassium compared with the earth a... | potassium isotopic evidence for a high-energy giant impact origin of the moon |
since 2014, nasa’s k2 mission has observed large portions of the ecliptic plane in search of transiting planets and has detected hundreds of planet candidates. with observations planned until at least early 2018, k2 will continue to identify more planet candidates. we present here 275 planet candidates observed during ... | 275 candidates and 149 validated planets orbiting bright stars in k2 campaigns 0-10 |
we report the delivery to the mikulski archive for space telescopes of target pixel and light curve files for up to 160,000 targets selected from full-frame images (ffi) for each tess northern hemisphere observing sector. the data include calibrated target pixels, simple aperture photometry flux time series, and presea... | tess science processing operations center ffi target list products |
dayside transients, such as hot flow anomalies, foreshock bubbles, magnetosheath jets, flux transfer events, and surface waves, are frequently observed upstream from the bow shock, in the magnetosheath, and at the magnetopause. they play a significant role in the solar wind-magnetosphere-ionosphere coupling. foreshock ... | dayside transient phenomena and their impact on the magnetosphere and ionosphere |
we investigate the observational signatures of super-earths (i.e., planets with earth-to-neptune mass), which are the most common type of exoplanet discovered to date, in their natal disks of gas and dust. combining two-fluid global hydrodynamics simulations with a radiative transfer code, we calculate the distribution... | multiple disk gaps and rings generated by a single super-earth |
we consider a simple generic dissipative dark matter model: a hidden sector featuring two dark matter particles charged under an unbroken u(1) ‧ interaction. previous work has shown that such a model has the potential to explain dark matter phenomena on both large and small scales. in this framework, the dark matter ha... | diurnal modulation signal from dissipative hidden sector dark matter |
of profound astrobiological interest, enceladus appears to have a global saline subsurface ocean, indicating water-rock reaction at present or in the past, an important mechanism in the moon's potential habitability. here, we investigate how salinity and the partition of heat production between the silicate core and th... | how does salinity shape ocean circulation and ice geometry on enceladus and other icy satellites? |
we present a methodology for the determination of empirical masses of single stars through the combination of three direct observables with gaia and transiting exoplanet survey satellite (tess): (i) the surface gravity via granulation-driven variations in the tess light curve, (ii) the bolometric flux at earth via the ... | empirical accurate masses and radii of single stars with tess and gaia |
an overview of plant surface structures and their evolution is presented. it combines surface chemistry and architecture with their functions and refers to possible biomimetic applications. within some 3.5 billion years biological species evolved highly complex multifunctional surfaces for interacting with their enviro... | plant surfaces: structures and functions for biomimetic innovations |
severe haze events during which particulate matter (pm) increases quickly from tens to hundreds of microgram per cubic meter in 1-2 days frequently occur in china. although it has been known that pm is influenced by complex interplays among emissions, meteorology, and physical and chemical processes, specific mechanism... | new positive feedback mechanism between boundary layer meteorology and secondary aerosol formation during severe haze events |
modern research on the origin of life started with urey-miller's 1953 report on the spontaneous formation of amino acids upon application of electric discharge on a model of the pristine earth atmosphere. formamide provides a chemically sound starting material for the syntheses of prebiotic compounds; its role in prebi... | meteorite-catalyzed syntheses of nucleosides and of other prebiotic compounds from formamide under proton irradiation |
context. understanding the diversity of planets requires studying the morphology and physical conditions in the protoplanetary disks in which they form.aims: we aim to study the structure of the ~10 myr old protoplanetary disk hd 100453, to detect features that can trace disk evolution and to understand the mechanisms ... | shadows and spirals in the protoplanetary disk hd 100453 |
pds 70b is a recently discovered and directly imaged exoplanet within the wide (≳40 au) cavity around pds 70. ongoing accretion onto the central star suggests that accretion onto pds 70b may also be ongoing. we present the first high-contrast images at hα (656 nm) and nearby continuum (643 nm) of pds 70 utilizing the m... | magellan adaptive optics imaging of pds 70: measuring the mass accretion rate of a young giant planet within a gapped disk |
we report 78 secondary eclipse depths for a sample of 36 transiting hot jupiters observed at 3.6 and 4.5 μm using the spitzer space telescope. our eclipse results for 27 of these planets are new, and include highly irradiated worlds such as kelt-7b, wasp-87b, wasp-76b, and wasp-64b, and important targets for james webb... | statistical characterization of hot jupiter atmospheres using spitzer's secondary eclipses |
detailed observations of gaps in protoplanetary disks have revealed structures that drive current research on circumstellar disks. one such feature is the two intensity nulls seen along the outer disk of the hd 142527 system, which are particularly well traced in polarized differential imaging. here we propose that the... | shadows cast by a warp in the hd 142527 protoplanetary disk |
context. transitional disks around young stars with large dust cavities are promising candidates to look for recently formed, embedded planets. models of planet-disk interaction predict that young planets clear a gap in the gas while trapping dust at larger radii. other physical mechanisms might also be responsible for... | resolved gas cavities in transitional disks inferred from co isotopologs with alma |
correct parameterization of the collision-induced absorption (cia) phenomena is essential for accurate modeling of planetary atmospheres. the hitran spectroscopic database provides these parameters in a dedicated section. here, we significantly revise and extend the hitran cia data with respect to the original effort d... | update of the hitran collision-induced absorption section |
nucleosynthetic isotope variability among solar system objects is often used to probe the genetic relationship between meteorite groups and the rocky planets (mercury, venus, earth and mars), which, in turn, may provide insights into the building blocks of the earth-moon system. using this approach, it has been inferre... | isotopic evolution of the protoplanetary disk and the building blocks of earth and the moon |
the structure and composition of granites provide clues to the nature of silicic volcanism, the formation of continents, and the rheological and thermal properties of the earth's upper crust as far back as the hadean eon during the nascent stages of the planet's formation1-4. the temperature of granite crystallization ... | low-temperature crystallization of granites and the implications for crustal magmatism |
the terrestrial planets accreted from a diverse suite of solar system materials ranging from strongly o-deficient materials similar to enstatite chondrites via ordinary chondrite materials to fully oxidised carbonaceous chondrite and cometary materials. heliocentric zoning with increasingly oxidised planetesimals outwa... | core formation, mantle differentiation and core-mantle interaction within earth and the terrestrial planets |
the trappist-1 planetary system provides an unprecedented opportunity to study terrestrial exoplanet evolution with the james webb space telescope (jwst) and ground-based observatories. since m dwarf planets likely experience extreme volatile loss, the trappist-1 planets may have highly evolved, possibly uninhabitable ... | evolved climates and observational discriminants for the trappist-1 planetary system |
context. stellar activity is the main limitation to the detection of an earth-twin using the radial-velocity (rv) technique. despite many efforts in trying to mitigate the effect of stellar activity using empirical and statistical techniques, it seems that we are facing an obstacle that will be extremely difficult to o... | measuring precise radial velocities on individual spectral lines. i. validation of the method and application to mitigate stellar activity |
the most abundant stars in the galaxy, m dwarfs, are very commonly hosts to diverse systems of low-mass planets. their abundancy implies that the general occurrence rate of planets is dominated by their occurrence rate around such m dwarfs. in this article, we combine the m dwarf surveys conducted with the hires/keck, ... | frequency of planets orbiting m dwarfs in the solar neighbourhood |
while giant extrasolar planets have been studied for more than two decades now, there are still some open questions as to their dominant formation and migration processes, as well as to their atmospheric evolution in different stellar environments. in this paper, we study a sample of giant transiting exoplanets detecte... | sophie velocimetry of kepler transit candidates. xvii. the physical properties of giant exoplanets within 400 days of period |
the basic structure of the solar system is set by the presence of low-mass terrestrial planets in its inner part and giant planets in its outer part. this is the result of the formation of a system of multiple embryos with approximately the mass of mars in the inner disk and of a few multi-earth-mass cores in the outer... | the great dichotomy of the solar system: small terrestrial embryos and massive giant planet cores |
the gas dynamics of weakly ionized protoplanetary disks (ppds) are largely governed by the coupling between gas and magnetic fields, described by three non-ideal magnetohydrodynamical (mhd) effects (ohmic, hall, ambipolar). previous local simulations incorporating these processes have revealed that the inner regions of... | global simulations of the inner regions of protoplanetary disks with comprehensive disk microphysics |
we present observations of the interstellar interloper 1i/2017 u1 (’oumuamua) taken during its 2017 october flyby of earth. the optical colors b - v = 0.70 ± 0.06, v - r = 0.45 ± 0.05, overlap those of the d-type jovian trojan asteroids and are incompatible with the ultrared objects that are abundant in the kuiper belt... | interstellar interloper 1i/2017 u1: observations from the not and wiyn telescopes |
measuring the distances to galactic planetary nebulae (pne) has been an intractable problem for many decades. we have now established a robust optical statistical distance indicator, the hα surface brightness-radius or shα-r relation, which addresses this problem. we developed this relation from a critically evaluated ... | the hα surface brightness-radius relation: a robust statistical distance indicator for planetary nebulae |
simulations predict that hot super-earth sized exoplanets can have their envelopes stripped by photoevaporation, which would present itself as a lack of these exoplanets. however, this absence in the exoplanet population has escaped a firm detection. here we demonstrate, using asteroseismology on a sample of exoplanets... | hot super-earths stripped by their host stars |
hat-p-20b is a giant metal-rich exoplanet orbiting a metal-rich star. we analyze two secondary eclipses of the planet in each of the 3.6 and 4.5 μm bands of warm spitzer. we have developed a simple, powerful, and radically different method to correct the intra-pixel effect for warm spitzer data, which we call pixel-lev... | spitzer secondary eclipses of the dense, modestly-irradiated, giant exoplanet hat-p-20b using pixel-level decorrelation |
a snow-line is the region of a protoplanetary disk at which a major volatile, such as water or carbon monoxide, reaches its condensation temperature. snow-lines play a crucial role in disk evolution by promoting the rapid growth of ice-covered grains. signatures of the carbon monoxide snow-line (at temperatures of arou... | imaging the water snow-line during a protostellar outburst |
since the release of the etopo1 global earth topography model through the us noaa in 2009, new or significantly improved topographic data sets have become available over antarctica, greenland and parts of the oceans. here, we present a suite of new 1‧ (arc-min) models of earth's topography, bedrock and ice-sheets const... | earth2014: 1 arc-min shape, topography, bedrock and ice-sheet models - available as gridded data and degree-10,800 spherical harmonics |
plant disease outbreaks are increasing and threaten food security for the vulnerable in many areas of the world. now a global human pandemic is threatening the health of millions on our planet. a stable, nutritious food supply will be needed to lift people out of poverty and improve health outcomes. plant diseases, bot... | the persistent threat of emerging plant disease pandemics to global food security |
proxima b is a planet with a minimum mass of 1.3m⊕ orbiting within the habitable zone (hz) of proxima centauri, a very low-mass, active star and the sun's closest neighbor. here we investigate a number of factors related to the potential habitability of proxima b and its ability to maintain liquid water on its surface.... | the habitability of proxima centauri b. i. irradiation, rotation and volatile inventory from formation to the present |
we review recent works on the dynamics of circumbinary accretion, including time variability, angular momentum transfer between the disk and the binary, and the secular evolution of accreting binaries. these dynamics impact stellar binary formation/evolution, circumbinary planet formation/migration, and the evolution o... | circumbinary accretion: from binary stars to massive binary black holes |
aims: we study the dependence of protoplanetary disk evolution on stellar mass using a large sample of young stellar objects in nearby young star-forming regions.methods: we update the protoplanetary disk fractions presented in our recent work (paper i of this series) derived for 22 nearby (<500 pc) associations bet... | protoplanetary disk lifetimes vs. stellar mass and possible implications for giant planet populations |
shortly after the seminal paper "self-organized criticality: an explanation of 1/ f noise" by bak et al. (1987), the idea has been applied to solar physics, in "avalanches and the distribution of solar flares" by lu and hamilton (1991). in the following years, an inspiring cross-fertilization from complexity theory to ... | 25 years of self-organized criticality: solar and astrophysics |
the interiors of giant planets remain poorly understood. even for the planets in the solar system, difficulties in observation lead to large uncertainties in the properties of planetary cores. exoplanets that have undergone rare evolutionary processes provide a route to understanding planetary interiors. planets found ... | a remnant planetary core in the hot-neptune desert |
gearbox fault diagnosis is expected to significantly improve the reliability, safety and efficiency of power transmission systems. however, planetary gearbox fault diagnosis remains a challenge due to complex responses caused by multiple planetary gears. model-based gearbox fault diagnosis techniques extract hand-craft... | planetary gearbox fault diagnosis using bidirectional-convolutional lstm networks |
atmospheres of exoplanets in the habitable zones around active young g-k-m stars are subject to extreme x-ray and euv (xuv) fluxes from their host stars that can initiate atmospheric erosion. atmospheric loss affects exoplanetary habitability in terms of surface water inventory, atmospheric pressure, the efficiency of ... | how hospitable are space weather affected habitable zones? the role of ion escape |
the 15 january 2022 hunga, tonga, volcano's explosive eruption produced the most powerful blast recorded in the last century, with an estimated equivalent tnt yield of 100-200 megatons. the blast energy was propagated through the atmosphere as various wave types. the most prominent wave was a long-period (>2000 s) s... | ims observations of infrasound and acoustic-gravity waves produced by the january 2022 volcanic eruption of hunga, tonga: a global analysis |
humanity is on a deeply unsustainable trajectory. we are exceeding planetary boundaries and unlikely to meet many international sustainable development goals and global environmental targets. until recently, there was no broadly accepted framework of interventions that could ignite the transformations needed to achieve... | levers and leverage points for pathways to sustainability |
finding life on exoplanets from telescopic observations is an ultimate goal of exoplanet science. life produces gases and other substances, such as pigments, which can have distinct spectral or photometric signatures. whether or not life is found with future data must be expressed with probabilities, requiring a framew... | exoplanet biosignatures: a framework for their assessment |
reliable estimates of extreme rainfall events are necessary for an accurate prediction of floods. most of the global rainfall products are available at a coarse resolution, rendering them less desirable for extreme rainfall analysis. therefore, regional mesoscale models such as the advanced research version of the weat... | assessment of the weather research and forecasting (wrf) model for simulation of extreme rainfall events in the upper ganga basin |
we analyzed more than 200 osiris nac images with a pixel scale of 0.9-2.4 m/pixel of comet 67p/churyumov-gerasimenko (67p) that have been acquired from onboard the rosetta spacecraft in august and september 2014 using stereo-photogrammetric methods (spg). we derived improved spacecraft position and pointing data for th... | shape model, reference system definition, and cartographic mapping standards for comet 67p/churyumov-gerasimenko - stereo-photogrammetric analysis of rosetta/osiris image data |
in this paper, we investigate and develop scaling laws as a function of external nondimensional control parameters for heat and momentum transport for nonrotating, slowly rotating, and rapidly rotating turbulent convection systems, with the end goal of forging connections and bridging the various gaps between these reg... | connections between nonrotating, slowly rotating, and rapidly rotating turbulent convection transport scalings |
context. imaged in the gap of a transition disk and found at a separation of about 195 mas ( 22 au) from its host star at a position angle of about 155°, pds 70 b is the most robustly detected young planet to date. this system is therefore a unique laboratory for characterizing the properties of young planetary systems... | highly structured disk around the planet host pds 70 revealed by high-angular resolution observations with alma |
we present k-band interferometric observations of the pds 70 protoplanets along with their host star using vlti/gravity. we obtained k-band spectra and 100 μas precision astrometry of both pds 70 b and c in two epochs, as well as spatially resolving the hot inner disk around the star. rejecting unstable orbits, we foun... | constraining the nature of the pds 70 protoplanets with vlti/gravity |
planets larger than earth and smaller than neptune are some of the most numerous in the galaxy, but observational efforts to understand this population have proved challenging because optically thick clouds or hazes at high altitudes obscure molecular features. we present models of super earths that include thick cloud... | thermal emission and reflected light spectra of super earths with flat transmission spectra |
ultra-hot jupiters are emerging as a new class of exoplanets. studying their chemical compositions and temperature structures will improve our understanding of their mass loss rate as well as their formation and evolution. we present the detection of ionized calcium in the two hottest giant exoplanets - kelt-9b and was... | ionized calcium in the atmospheres of two ultra-hot exoplanets wasp-33b and kelt-9b |
recently, many earth-sized planets have been discovered around stars other than the sun that might possess appropriate conditions for life. the development of theoretical methods for assessing the putative habitability of these worlds is of paramount importance, since it serves the dual purpose of identifying and quant... | colloquium: physical constraints for the evolution of life on exoplanets |
the orbital eccentricities of directly imaged exoplanets and brown dwarf companions provide clues about their formation and dynamical histories. we combine new high-contrast imaging observations of substellar companions obtained primarily with keck/nirc2 together with astrometry from the literature to test for differen... | population-level eccentricity distributions of imaged exoplanets and brown dwarf companions: dynamical evidence for distinct formation channels |
we present stellar and planetary properties for 1305 kepler objects of interest hosting 2025 planet candidates observed as part of the california-kepler survey. we combine spectroscopic constraints, presented in paper i, with stellar interior modeling to estimate stellar masses, radii, and ages. stellar radii are typic... | the california-kepler survey. ii. precise physical properties of 2025 kepler planets and their host stars |
we present exoplanets as new targets to discover dark matter (dm). throughout the milky way, dm can scatter, become captured, deposit annihilation energy, and increase the heat flow within exoplanets. we estimate upcoming infrared telescope sensitivity to this scenario, finding actionable discovery or exclusion searche... | exoplanets as sub-gev dark matter detectors |
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