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we extend our calculation of the atmospheric neutrino fluxes to polar and tropical regions. it is well known that the air density profiles in the polar and the tropical regions are different from the mid-latitude region. also there are large seasonal variations in the polar region. in this extension, we use the nrlmsis... | atmospheric neutrino flux calculation using the nrlmsise-00 atmospheric model |
m-dwarf stars—hydrogen-burning stars that are smaller than 60 per cent of the size of the sun—are the most common class of star in our galaxy and outnumber sun-like stars by a ratio of 12:1. recent results have shown that m dwarfs host earth-sized planets in great numbers: the average number of m-dwarf planets that are... | a rocky planet transiting a nearby low-mass star |
accretion disks around supermassive black holes (smbhs) in active galactic nuclei (agns) contain stars, stellar mass black holes, and other stellar remnants, which perturb the disk gas gravitationally. the resulting density perturbations exert torques on the embedded masses causing them to migrate through the disk in a... | migration traps in disks around supermassive black holes |
trends in the planet population with host star mass provide an avenue to constrain planet formation theories. we derive the planet radius distribution function for kepler stars of different spectral types, sampling a range in host star masses. we find that m dwarf stars have 3.5 times more small planets (1.0-2.8 r⨁) th... | an increase in the mass of planetary systems around lower-mass stars |
the trappist-1 system, consisting of an ultracool host star having seven known earth-sized planets, will be a prime target for atmospheric characterization with the james webb space telescope (jwst). however, the detectability of atmospheric molecular species may be severely impacted by the presence of clouds and/or ha... | impact of clouds and hazes on the simulated jwst transmission spectra of habitable zone planets in the trappist-1 system |
we report the results of a ∼4 yr direct imaging survey of 104 stars to resolve and characterize circumstellar debris disks in scattered light as part of the gemini planet imager (gpi) exoplanet survey. we targeted nearby (≲150 pc), young (≲500 myr) stars with high infrared (ir) excesses (lir/l⋆ > 10-5), including 38... | debris disk results from the gemini planet imager exoplanet survey's polarimetric imaging campaign |
planet labs ("planet") operate the largest fleet of active nano-satellites in orbit, offering an unprecedented monitoring capacity of daily and global rgb image capture at 3–5 m resolution. however, limitations in spectral resolution and lack of accurate radiometric sensor calibration impact the utility of this rich in... | high-resolution ndvi from planet's constellation of earth observing nano-satellites: a new data source for precision agriculture |
we describe the discovery of a solar neighborhood (d = 468 pc) binary system with a main-sequence sunlike star and a massive noninteracting black hole candidate. the spectral energy distribution of the visible star is described by a single stellar model. we derive stellar parameters from a high signal-to-noise magellan... | a noninteracting galactic black hole candidate in a binary system with a main-sequence star |
three earth-sized exoplanets were recently discovered close to the habitable zone of the nearby ultracool dwarf star trappist-1 (ref. 3). the nature of these planets has yet to be determined, as their masses remain unmeasured and no observational constraint is available for the planetary population surrounding ultracoo... | a combined transmission spectrum of the earth-sized exoplanets trappist-1 b and c |
terrestrial planets in the habitable zones (hzs) of low-mass stars and cool dwarfs have received significant scrutiny recently. transit spectroscopy of such planets with the james webb space telescope (jwst) represents our best shot at obtaining the spectrum of a habitable planet within the next decade. as these planet... | habitable moist atmospheres on terrestrial planets near the inner edge of the habitable zone around m dwarfs |
we present a new age-dating technique that combines gyrochronology with isochrone fitting to infer ages for fgkm main-sequence and subgiant field stars. gyrochronology and isochrone fitting are each capable of providing relatively precise ages for field stars in certain areas of the hertzsprung-russell diagram (hrd): g... | toward precise stellar ages: combining isochrone fitting with empirical gyrochronology |
we report the transiting exoplanet survey satellite (tess) discovery of three terrestrial-size planets transiting l 98-59 (toi-175, tic 307210830)—a bright m dwarf at a distance of 10.6 pc. using the gaia-measured distance and broadband photometry, we find that the host star is an m3 dwarf. combined with the tess trans... | the l 98-59 system: three transiting, terrestrial-size planets orbiting a nearby m dwarf |
the history of mars’ atmosphere is important for understanding the geological evolution and potential habitability of the planet. we determine the amount of gas lost to space through time using measurements of the upper-atmospheric structure made by the mars atmosphere and volatile evolution (maven) spacecraft. we deri... | mars’ atmospheric history derived from upper-atmosphere measurements of 38ar/36ar |
context. the mid-infrared instrument (miri) onboard the james webb space telescope (jwst) will provide imaging, coronagraphy, low-resolution spectroscopy, and medium-resolution spectroscopy at unprecedented sensitivity levels in the mid-infrared wavelength range. the medium resolution spectrometer (mrs) of miri is an i... | wavelength calibration and resolving power of the jwst miri medium resolution spectrometer |
the effects of hydrocarbon reactions and diamond precipitation on the internal structure and evolution of icy giant planets such as neptune and uranus have been discussed for more than three decades1. inside these celestial bodies, simple hydrocarbons such as methane, which are highly abundant in the atmospheres2, are ... | formation of diamonds in laser-compressed hydrocarbons at planetary interior conditions |
exocross is a fortran code for generating spectra (emission, absorption) and thermodynamic properties (partition function, specific heat, etc.) from molecular line lists. input is taken in several formats, including exomol and hitran formats. exocross is efficiently parallelized showing also a high degree of vectorizat... | exocross: a general program for generating spectra from molecular line lists |
nasa's dragonfly mission will send a rotorcraft lander to the surface of titan in the mid-2030s. dragonfly's science themes include investigation of titan's prebiotic chemistry, habitability, and potential chemical biosignatures from both water-based "life as we know it" (as might occur in the interior mantle ocean, po... | science goals and objectives for the dragonfly titan rotorcraft relocatable lander |
current theories of planetary evolution predict that infant giant planets have large radii and very low densities before they slowly contract to reach their final size after about several hundred million years1,2. these theoretical expectations remain untested so far as the detection and characterization of very young ... | rapid contraction of giant planets orbiting the 20-million-year-old star v1298 tau |
this paper reviews methods to compensate for matrix effects and self-absorption during quantitative analysis of compositions of solids measured using laser induced breakdown spectroscopy (libs) and their applications to in-situ analysis. methods to reduce matrix and self-absorption effects on calibration curves are fir... | quantitative methods for compensation of matrix effects and self-absorption in laser induced breakdown spectroscopy signals of solids |
analyses of seismic data from the insight mission have provided the first in situ constraints on the thickness of the crust of mars. these crustal thickness constraints are currently limited to beneath the lander that is located in the northern lowlands, and we use gravity and topography data to construct global crusta... | insight constraints on the global character of the martian crust |
reversing the ongoing degradation of the planet's ecosystems requires timely and detailed monitoring of ecosystem change and uses. yet, the system of national accounts (sna), first developed in response to the economic crisis of the 1930s and used by statistical offices worldwide to record economic activity (for exampl... | progress in natural capital accounting for ecosystems |
surveys have shown that super-earth and neptune-mass exoplanets are more frequent than gas giants around low-mass stars, as predicted by the core accretion theory of planet formation. we report the discovery of a giant planet around the very-low-mass star gj 3512, as determined by optical and near-infrared radial-veloc... | a giant exoplanet orbiting a very-low-mass star challenges planet formation models |
photoevaporation of planet-forming discs by high-energy radiation from the central star is potentially a crucial mechanism for disc evolution and it may play an important role in the formation and evolution of planetary systems. we present here a new generation of x-ray photoevaporation models for solar-type stars, bas... | the dispersal of protoplanetary discs - i. a new generation of x-ray photoevaporation models |
the chemical composition of the sun is an essential piece of reference data for astronomy, cosmology, astroparticle, space and geo-physics: elemental abundances of essentially all astronomical objects are referenced to the solar composition, and basically every process involving the sun depends on its composition. this... | the elemental composition of the sun. i. the intermediate mass elements na to ca |
the total gas mass of a protoplanetary disk is a fundamental, but poorly determined, quantity. a new technique has been demonstrated to assess directly the bulk molecular gas reservoir of molecular hydrogen using the hd j = 1-0 line at 112 μm. in this work we present a herschel space observatory 10 survey of six additi... | mass measurements in protoplanetary disks from hydrogen deuteride |
three known examples of coherent emission in radio astronomical sources are reviewed: plasma emission, electron cyclotron maser emission (ecme) and pulsar radio emission. plasma emission is a multi-stage mechanism with the first stage being generation of langmuir waves through a streaming instability, and subsequent st... | coherent emission mechanisms in astrophysical plasmas |
spectroscopy of exoplanetary atmospheres has become a well established method for the characterization of extrasolar planets. we here present a novel inverse retrieval code for exoplanetary atmospheres. t-rex(tau retrieval for exoplanets) is a line-by-line radiative transfer fully bayesian retrieval framework. t-rex in... | tau-rex i: a next generation retrieval code for exoplanetary atmospheres |
the abundances of carbon, oxygen, and iron in late-type stars are important parameters in exoplanetary and stellar physics, as well as key tracers of stellar populations and galactic chemical evolution. however, standard spectroscopic abundance analyses can be prone to severe systematic errors, based on the assumption ... | carbon, oxygen, and iron abundances in disk and halo stars. implications of 3d non-lte spectral line formation |
joint statistics of periods and mass ratios of close binaries and its dependence on primary mass can be explained by assuming that seed binary companions are formed by disc fragmentation at random intervals during assemblage of stellar mass and migrate inwards as they accrete from the circumbinary disc. a toy model bas... | formation of close binaries by disc fragmentation and migration, and its statistical modelling |
regular, low-cost decadal-class science missions to planetary destinations will be enabled by high-δv small spacecraft, such as the high-energy photon, and small launch vehicles, such as electron, to support expanding opportunities for scientists and to increase the rate of science return. the rocket lab mission to ven... | rocket lab mission to venus |
ultrahot jupiters are gas giants that orbit so close to their host star that they are tidally locked, causing a permanent hot dayside and a cooler nightside. signatures of their nonuniform atmospheres can be observed with high-resolution transit transmission spectroscopy by resolving time-dependent velocity shifts as t... | an atomic spectral survey of wasp-76b: resolving chemical gradients and asymmetries |
solar orbiter is the first space mission observing the solar plasma both in situ and remotely, from a close distance, in and out of the ecliptic. the ultimate goal is to understand how the sun produces and controls the heliosphere, filling the solar system and driving the planetary environments. with six remote-sensing... | the solar orbiter science activity plan. translating solar and heliospheric physics questions into action |
over the past few decades, it has become increasingly clear that the impact of interplanetary bodies on other planetary bodies is one of the most ubiquitous and important geological processes in the solar system. this impact process has played a fundamental role throughout the history of the earth and other planetary b... | impact earth: a review of the terrestrial impact record |
ice-rich planets are formed exterior to the water ice line and thus are expected to contain a substantial amount of ice. the high ice content leads to unique conditions in the interior, under which the structure of a planet is affected by ice interaction with other metals. we apply experimental data of ice-rock interac... | a new perspective on the interiors of ice-rich planets: ice-rock mixture instead of ice on top of rock |
molecular nitrogen (n2) is thought to have been the most abundant form of nitrogen in the protosolar nebula. it is the main n-bearing molecule in the atmospheres of pluto and triton and probably the main nitrogen reservoir from which the giant planets formed. yet in comets, often considered the most primitive bodies in... | molecular nitrogen in comet 67p/churyumov-gerasimenko indicates a low formation temperature |
the atmospheric temperatures of the ultra-hot jupiter kelt-9b straddle the transition between gas giants and stars, and therefore between two traditionally distinct regimes of atmospheric chemistry. previous theoretical studies assume the atmosphere of kelt-9b to be in chemical equilibrium. despite the high ultraviolet... | the peculiar atmospheric chemistry of kelt-9b |
for the calculation of complex neutral/ionized gas-phase chemical equilibria, we present a semi-analytical, versatile, and efficient computer program, called fastchem. the applied method is based on the solution of a system of coupled non-linear (and linear) algebraic equations, namely the law of mass action and the el... | fastchem: a computer program for efficient complex chemical equilibrium calculations in the neutral/ionized gas phase with applications to stellar and planetary atmospheres |
terrestrial planets at the inner edge of the habitable zone (hz) of late-k and m-dwarf stars are expected to be in synchronous rotation, as a consequence of strong tidal interactions with their host stars. previous global climate model (gcm) studies have shown that, for slowly rotating planets, strong convection at the... | the inner edge of the habitable zone for synchronously rotating planets around low-mass stars using general circulation models |
we present 1.3 mm continuum alma long-baseline observations at 3-5 au resolution of 10 of the brightest discs from the ophiuchus disc survey employing alma (odisea) project. we identify a total of 26 narrow rings and gaps distributed in 8 sources and 3 discs with small dust cavities (r <10 au). we find that two disc... | the ophiuchus disc survey employing alma (odisea) - iii. the evolution of substructures in massive discs at 3-5 au resolution |
the distribution and isotopic composition of volatile elements in planetary materials holds a key to the characterization of the early solar system and the moon's formation. the moon and earth are chemically and isotopically very similar. however, the moon is highly depleted in volatile elements and the origin of this ... | gallium isotopic evidence for extensive volatile loss from the moon during its formation |
floods in the venice city centre result from the superposition of several factors: astronomical tides; seiches; and atmospherically forced fluctuations, which include storm surges, meteotsunamis, and surges caused by atmospheric planetary waves. all these factors can contribute to positive water height anomalies indivi... | extreme floods of venice: characteristics, dynamics, past and future evolution (review article) |
latin america has the planet’s largest land reserves for agriculture and had the most rapid agricultural expansion during the twenty-first century. a large portion of the expansion replaced forests, as shown by many local and regional studies. however, expansion varied regionally and also replaced other land covers. fu... | cropland/pastureland dynamics and the slowdown of deforestation in latin america |
atom probe tomography (apt) is an analytical technique that provides quantitative three‑dimensional elemental and isotopic analyses at sub‑nanometre resolution across the whole periodic table. although developed and mostly used in the materials science and semiconductor fields, recent years have seen increasing develop... | atom probe tomography: development and application to the geosciences |
the importance of zircon in geochemical and geochronological studies, and its presence not only in aluminous but also in alkaline rocks, prompted us to think about a new zircon saturation model that can be applied in a wide range of compositions. therefore, we performed zircon crystallization experiments in a range of ... | zircon saturation in silicate melts: a new and improved model for aluminous and alkaline melts |
transmission spectroscopy provides us with information on the atmospheric properties at the limb, which is often intuitively assumed to be a narrow annulus around the planet. consequently, studies have focused on the effect of atmospheric horizontal heterogeneities along the limb. here we demonstrate that the region pr... | effects of a fully 3d atmospheric structure on exoplanet transmission spectra: retrieval biases due to day-night temperature gradients |
this paper summarises some of the recent progress that has been made in understanding astrophysical plasma turbulence in the solar wind, from in situ spacecraft observations. at large scales, where the turbulence is predominantly alfvénic, measurements of critical balance, residual energy and three-dimensional structur... | recent progress in astrophysical plasma turbulence from solar wind observations |
we model the impact of nonuniform cloud cover on transit transmission spectra. patchy clouds exist in nearly every solar system atmosphere, brown dwarfs, and transiting exoplanets. our major findings suggest that fractional cloud coverage can exactly mimic high mean molecular weight atmospheres and vice versa over cert... | the influence of nonuniform cloud cover on transit transmission spectra |
transmission spectroscopy is still the preferred characterization technique for exoplanet atmospheres, although it presents unique challenges which translate into characterization bottlenecks when robust mitigation strategies are missing. stellar contamination is one of such challenges that can overpower the planetary ... | towards robust corrections for stellar contamination in jwst exoplanet transmission spectra |
the rate of magnetic reconnection is of the utmost importance in a variety of processes because it controls, for example, the rate energy is released in solar flares, the speed of the dungey convection cycle in earth's magnetosphere, and the energy release rate in harmful geomagnetic substorms. it is known from numeric... | first-principles theory of the rate of magnetic reconnection in magnetospheric and solar plasmas |
we present a systematic search for transiting giant planets ($0.6 \mbox{$r_{\rm j}$}\le \mbox{$r_{\rm p}$}\le 2.0 \mbox{$r_{\rm j}$}$) orbiting nearby low-mass stars ($\mbox{$m_{*}$}\le 0.71 \mbox{${\rm m}_{\odot }$}$). the formation of giant planets around low-mass stars is predicted to be rare by the core-accretion p... | the occurrence rate of giant planets orbiting low-mass stars with tess |
in china, a significant reduction in primary pollution has been observed due to the clean air action since 2013, and ozone pollution has become increasingly prominent over the past years. pearl river delta (prd) is one of the most successful regions concerning primary pollution control, while is suffering from severe o... | an explicit study of local ozone budget and nox-vocs sensitivity in shenzhen china |
the radiant energy budget and internal heat are fundamental properties of giant planets, but precise determination of these properties remains a challenge. here, we report measurements of jupiter's radiant energy budget and internal heat based on cassini multi-instrument observations. our findings reveal that jupiter's... | less absorbed solar energy and more internal heat for jupiter |
the full-phase infrared light curves of low-eccentricity hot jupiters show a trend of increasing dayside-to-nightside brightness temperature difference with increasing equilibrium temperature. here, we present a three-dimensional model that explains this relationship, in order to provide insight into the processes that... | atmospheric circulation of hot jupiters: dayside-nightside temperature differences |
the synchrosqueezing transform can effectively improve the readability of time-frequency representation of mono-component and constant frequency signals. however, for multi-component and time-variant frequency signals, it still suffers from time-frequency blurs. in order to address this issue, the synchrosqueezing tran... | iterative generalized synchrosqueezing transform for fault diagnosis of wind turbine planetary gearbox under nonstationary conditions |
long-distance terrestrial migrations are imperiled globally. we determined both round-trip migration distances (straight-line measurements between migratory end points) and total annual movement (sum of the distances between successive relocations over a year) for a suite of large mammals that had potential for long-di... | longest terrestrial migrations and movements around the world |
we report a calculation of time-dependent quasi-geostrophic core flows for 1940-2010. inverting recursively for an ensemble of solutions, we evaluate the main source of uncertainties, namely, the model errors arising from interactions between unresolved core surface motions and magnetic fields. temporal correlations of... | planetary gyre, time-dependent eddies, torsional waves, and equatorial jets at the earth's core surface |
an exceptionally strong stationary planetary wave with zonal wavenumber 1 led to a sudden stratospheric warming (ssw) in the southern hemisphere in september 2019. ionospheric data from european space agency's swarm satellite constellation mission show prominent 6-day variations in the dayside low-latitude region at th... | september 2019 antarctic sudden stratospheric warming: quasi-6-day wave burst and ionospheric effects |
planetary nebulae are traditionally considered to represent the final evolutionary stage of all intermediate-mass stars (∼0.7-8 m⊙). recent evidence seems to contradict this picture. in particular, since the launch of the hubble space telescope, it has been clear that planetary nebulae display a wide range of striking ... | binary stars as the key to understanding planetary nebulae |
context. until recently, the 3d shape, and therefore density (when combining the volume estimate with available mass estimates), and surface topography of the vast majority of the largest (d ≥ 100 km) main-belt asteroids have remained poorly constrained. the improved capabilities of the sphere/zimpol instrument have op... | vlt/sphere imaging survey of the largest main-belt asteroids: final results and synthesis |
the recent candidate detection of ∼1 ppb of phosphine in the middle atmosphere of venus is so unexpected that it requires an exhaustive search for explanations of its origin. phosphorus-containing species have not been modeled for venus' atmosphere before, and our work represents the first attempt to model phosphorus s... | phosphine on venus cannot be explained by conventional processes |
the james webb space telescope (jwst) presents the opportunity to transform our understanding of planets and the origins of life by revealing the atmospheric compositions, structures, and dynamics of transiting exoplanets in unprecedented detail. however, the high-precision, timeseries observations required for such in... | the transiting exoplanet community early release science program for jwst |
context. a key piece of information to understand the origin and role of protoplanetary disk substructures is their dust content. in particular, disk substructures associated with gas pressure bumps can work as dust traps, accumulating grains and reaching the necessary conditions to trigger the streaming instability.ai... | characterizing the dust content of disk substructures in tw hydrae |
a multi-axis differential optical absorption spectroscopy (max-doas) instrument was deployed in may and june 2016 at a monitoring station (37.18∘ n, 114.36∘ e) in the suburban area of xingtai, which is one of the most polluted cities in the north china plain (ncp), during the atmosphere-aerosol-boundary layer-cloud (a2... | vertical profiles of no2, so2, hono, hcho, chocho and aerosols derived from max-doas measurements at a rural site in the central western north china plain and their relation to emission sources and effects of regional transport |
the impactor-to-crater size scaling relationships that enable estimates of planetary surface ages rely on an accurate formulation of impactor-target physics. an armouring regime, specific to rubble-pile surfaces, has been proposed to occur when an impactor is comparable in diameter to a target surface particle (for exa... | crater population on asteroid (101955) bennu indicates impact armouring and a young surface |
few topics in geobiology have been as extensively debated as the role of earth's oxygenation in controlling when and why animals emerged and diversified. all currently described animals require oxygen for at least a portion of their life cycle. therefore, the transition to an oxygenated planet was a prerequisite for th... | on the co‑evolution of surface oxygen levels and animals |
aims: one of the biggest problems we can encounter while dealing with the limb-darkening coefficients for stellar atmospheric models with spherical symmetry is the difficulty of adjusting both the limb and the central parts simultaneously. in particular, the regions near the drop-offs are not well reproduced for most m... | a new method to compute limb-darkening coefficients for stellar atmosphere models with spherical symmetry: the space missions tess, kepler, corot, and most |
as spiral waves driven by a planet in a gaseous disk steepen into a shock, they deposit angular momentum, opening a gap in the disk. this has been well studied using both linear theory and numerical simulations, but so far only for the primary spiral arm: the one directly attached to the planet. using 2d hydrodynamic s... | on the formation of multiple concentric rings and gaps in protoplanetary disks |
planets acquire atmospheres from their parent circumstellar disks. we derive a general analytic expression for how the atmospheric mass grows with time t as a function of the underlying core mass {m}{core} and nebular conditions, including the gas metallicity z. planets accrete as much gas as can cool: an atmosphere's ... | to cool is to accrete: analytic scalings for nebular accretion of planetary atmospheres |
we report observations of resolved c2h emission rings within the gas-rich protoplanetary disks of tw hya and dm tau using the atacama large millimeter array. in each case the emission ring is found to arise at the edge of the observable disk of millimeter-sized grains (pebbles) traced by submillimeter-wave continuum em... | hydrocarbon emission rings in protoplanetary disks induced by dust evolution |
low-frequency (ν ≲ 150 mhz) stellar radio emission is expected to originate in the outer corona at heights comparable to and larger than the stellar radius. such emission from the sun has been used to study coronal structure, mass ejections and space-weather conditions around the planets1. searches for low-frequency em... | coherent radio emission from a quiescent red dwarf indicative of star-planet interaction |
the processes that led to the formation of the planetary bodies in the solar system are still not fully understood. using the results obtained with the comprehensive suite of instruments onboard the european space agency's rosetta mission, we present evidence that comet 67p/churyumov-gerasimenko likely formed through t... | evidence for the formation of comet 67p/churyumov-gerasimenko through gravitational collapse of a bound clump of pebbles |
wide-field surveys for transiting planets are well suited to searching diverse stellar populations, enabling a better understanding of the link between the properties of planets and their parent stars. we report the discovery of hat-p-69 b (toi 625.01) and hat-p-70 b (toi 624.01), two new hot jupiters around a stars fr... | two new hatnet hot jupiters around a stars and the first glimpse at the occurrence rate of hot jupiters from tess |
planet formation is thought to occur in discs around young stars by the aggregation of small dust grains into much larger objects. the growth from grains to pebbles and from planetesimals to planets is now fairly well understood. the intermediate stage has however been found to be hindered by the radial-drift and fragm... | self-induced dust traps: overcoming planet formation barriers |
the atmosphere plays a fundamental role in the transport of microbes across the planet but it is often neglected as a microbial habitat. although the ocean represents two thirds of the earth's surface, there is little information on the atmospheric microbial load over the open ocean. here we provide a global estimate o... | long-range transport of airborne microbes over the global tropical and subtropical ocean |
as an exoplanet transits its host star, some of the light from the star is absorbed by the atoms and molecules in the planet’s atmosphere, causing the planet to seem bigger; plotting the planet’s observed size as a function of the wavelength of the light produces a transmission spectrum. measuring the tiny variations i... | detection of titanium oxide in the atmosphere of a hot jupiter |
the early evolution of planetesimals and planets can be constrained using variations in the abundance of neodymium-142 (142nd), which arise from the initial distribution of 142nd within the protoplanetary disk and the radioactive decay of the short-lived samarium-146 isotope (146sm). the apparent offset in 142nd abunda... | primitive solar system materials and earth share a common initial 142nd abundance |
policy directives in several nations are focusing on the development of smart cities, linking innovations in the data sciences with the goal of advancing human well-being and sustainability on a highly urbanized planet. to achieve this goal, smart initiatives must move beyond city-level data to a higher-order understan... | meta-principles for developing smart, sustainable, and healthy cities |
the streaming instability concentrates solid particles in protoplanetary disks, leading to gravitational collapse into planetesimals. despite its key role in producing particle clumping and determining critical length scales in the instability’s linear regime, the influence of the disk’s radial pressure gradient on pla... | the mass and size distribution of planetesimals formed by the streaming instability. ii. the effect of the radial gas pressure gradient |
field stars are frequently formed in pairs, and many of these binaries are part of triples or even higher-order systems. even though, the principles of single stellar evolution and binary evolution, have been accepted for a long time, the long-term evolution of stellar triples is poorly understood. the presence of a th... | the evolution of hierarchical triple star-systems |
we present a catalog of panchromatic spectral energy distributions (seds) for 7 m and 4 k dwarf stars that span x-ray to infrared wavelengths (5 å -5.5 μm). these seds are composites of chandra or xmm-newton data from 5-∼50 å, a plasma emission model from ∼50-100 å, broadband empirical estimates from 100-1170 å, hubble... | the muscles treasury survey. iii. x-ray to infrared spectra of 11 m and k stars hosting planets |
context. ground-based high-dispersion (r ~ 100 000) spectroscopy (hds) is proving to be a powerful technique with which to characterize extrasolar planets. the planet signal is distilled from the bright starlight, combining ral and time-differential filtering techniques. in parallel, high-contrast imaging (hci) is deve... | combining high-dispersion spectroscopy with high contrast imaging: probing rocky planets around our nearest neighbors |
context. the physical and chemical conditions in class 0/i protostars are fundamental in unlocking the protostellar accretion process and its impact on planet formation.aims: the aim is to determine which physical components are traced by different molecules at subarcsecond scales (<100-400 au).methods: we used a su... | which molecule traces what: chemical diagnostics of protostellar sources |
au mic is a young (~24 myr), pre-main-sequence m dwarf star that was observed in the first month of science observations of the transiting exoplanet survey satellite (tess) and reobserved 2 years later. this target has photometric variability from a variety of sources that is readily apparent in the tess light curves; ... | flares, rotation, and planets of the au mic system from tess observations |
trappist-1 is a nearby 0.08 m⊙ m-star that was recently found to harbor a planetary system of at least seven earth-sized planets, all within 0.1 au. the configuration confounds theorists as the planets are not easily explained by either in situ or migration models. in this paper we present a scenario for the formation ... | formation of trappist-1 and other compact systems |
broad absorption signatures from alkali metals, such as the sodium (na i) and potassium (k i) resonance doublets, have long been predicted in the optical atmospheric spectra of cloud-free irradiated gas giant exoplanets1-3. however, observations have revealed only the narrow cores of these features rather than the full... | an absolute sodium abundance for a cloud-free `hot saturn' exoplanet |
ocean worlds is the label given to objects in the solar system that host stable, globe-girdling bodies of liquid water-"oceans". of these, the earth is the only one to support its oceans on the surface, making it a model for habitable planets around other stars but not for habitable worlds elsewhere in the solar system... | ocean worlds exploration |
previous studies have reported boundary layer features related to air pollution. however, few studies have comprehensively evaluated the characteristics and mechanisms of vertical wind in the formation and evolution of heavy particulate matter pollution episodes (ep) in hong kong. in this study, we analyzed the vertica... | characteristics of heavy particulate matter pollution events over hong kong and their relationships with vertical wind profiles using high-time-resolution doppler lidar measurements |
in earth and planetary sciences, the chemical composition of chondritic meteorites provides an essential reference to constrain the composition and differentiation history of planetary reservoirs. yet, for many trace elements, and in particular for volatile trace elements the composition of chondrites is not well const... | the chemical composition of carbonaceous chondrites: implications for volatile element depletion, complementarity and alteration |
solar-type binaries with short orbital periods ({p}{close}\equiv 1{--}10 days a ≲ 0.1 au) cannot form directly via fragmentation of molecular clouds or protostellar disks, yet their component masses are highly correlated, suggesting interaction during the pre-main-sequence (pre-ms) phase. moreover, the close binary fra... | dynamical formation of close binaries during the pre-main-sequence phase |
earth's surface topography is a direct physical expression of our planet's dynamics. most is isostatic, controlled by thickness and density variations within the crust and lithosphere, but a substantial proportion arises from forces exerted by underlying mantle convection. this dynamic topography directly connects the ... | earth's multi-scale topographic response to global mantle flow |
the exoplanet population characterized by relatively short orbital periods (p < 100 d) around solar-type stars is dominated by super-earths and sub-neptunes. however, these planets are missing in our solar system and the reason behind this absence is still unknown. two theoretical scenarios invoke the role of jupite... | cold jupiters and improved masses in 38 kepler and k2 small planet systems from 3661 harps-n radial velocities. no excess of cold jupiters in small planet systems |
chemical compositions of giant planets provide a means to constrain how and where they form. traditionally, super-stellar elemental abundances in giant planets were thought to be possible due to accretion of metal-rich solids. such enrichments are accompanied by oxygen-rich compositions (i.e. c/o below the disc's value... | chemical enrichment of giant planets and discs due to pebble drift |
transmission spectra probe exoplanetary atmospheres, but they can also be strongly affected by heterogeneities in host star photospheres through the transit light source effect. here we build upon our recent study of the effects of unocculted spots and faculae on m-dwarf transmission spectra, extending the analysis to ... | the transit light source effect. ii. the impact of stellar heterogeneity on transmission spectra of planets orbiting broadly sun-like stars |
context. we have obtained precise radial velocities for a sample of 373 g and k type giants at lick observatory regularly over more than 12 years. planets have been identified around 15 of these giant stars, and an additional 20 giant stars host planet candidates.aims: we are interested in the occurrence rate of subste... | precise radial velocities of giant stars. vii. occurrence rate of giant extrasolar planets as a function of mass and metallicity |
in recent years, the advent of a new generation of radial velocity instruments has allowed us to detect planets with increasingly lower mass and to break the one earth-mass barrier. here we report a new milestone in this context by announcing the detection of the lowest-mass planet measured so far using radial velociti... | warm terrestrial planet with half the mass of venus transiting a nearby star |
context. the main goal of the carmenes survey is to find earth-mass planets around nearby m-dwarf stars. seven m dwarfs included in the carmenes sample had been observed before with hires and harps and either were reported to have one short period planetary companion (gj 15 a, gj 176, gj 436, gj 536 and gj 1148) or are... | the carmenes search for exoplanets around m dwarfs . first visual-channel radial-velocity measurements and orbital parameter updates of seven m-dwarf planetary systems |
the concentration and distribution of water in the earth has influenced its evolution throughout its history. even at the trace levels contained in the planet's deep interior (mantle and core), water affects earth's thermal, deformational, melting, electrical and seismic properties, that control differentiation, plate ... | water in the earth's interior: distribution and origin |
exoplanets transiting bright nearby stars are key objects for advancing our knowledge of planetary formation and evolution. the wealth of photons from the host star gives detailed access to the atmospheric, interior and orbital properties of the planetary companions. ν2 lupi (hd 136352) is a naked-eye (v = 5.78) sun-li... | transit detection of the long-period volatile-rich super-earth ν2 lupi d with cheops |
the united nations proclaims that sustainable development comprises environmental, economic, and social sustainability. fisheries contribute to livelihoods, food security, and human health worldwide; however, as the planet's last major hunting and gathering industry, whether, and if so, how fishing can achieve all thre... | three pillars of sustainability in fisheries |
the synchrosqueezing transform (sst) is a powerful tool for time-frequency analysis of signals with slowly varying instantaneous frequency (if). however, the sst and its extensions provide poor time-frequency resolution for signals with wide frequency range and fast varying if. in this paper, a new sst method called hi... | high-order synchrosqueezing wavelet transform and application to planetary gearbox fault diagnosis |
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