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it is possible to learn about the orientation of a star's rotation axis by combining measurements of the star's rotation velocity (v) and its projection onto our line of sight (v sin i). this idea has found many applications, including the investigation of the obliquities of stars with transiting planets. here, we pres... | on the inference of a star's inclination angle from its rotation velocity and projected rotation velocity |
context. the formation of planets strongly depends on the total amount as well as on the spatial distribution of solids in protoplanetary disks. thanks to the improvements in resolution and sensitivity provided by alma, measurements of the surface density of mm-sized grains are now possible on large samples of disks. s... | physical properties of dusty protoplanetary disks in lupus: evidence for viscous evolution? |
we carry out numerical simulations of circumbinary discs, solving the viscous hydrodynamics equations on a polar grid covering an extended disc outside the binary co-orbital region. we use carefully controlled outer boundary conditions and long-term integrations to ensure that the disc reaches a quasi-steady state, in ... | viscous hydrodynamics simulations of circumbinary accretion discs: variability, quasi-steady state and angular momentum transfer |
the surface elemental composition of dwarf planet ceres constrains its regolith ice content, aqueous alteration processes, and interior evolution. using nuclear spectroscopy data acquired by nasa’s dawn mission, we determined the concentrations of elemental hydrogen, iron, and potassium on ceres. the data show that sur... | extensive water ice within ceres’ aqueously altered regolith: evidence from nuclear spectroscopy |
meteorological conditions play important roles in the formation of ozone (o3) and fine particulate matter (pm2.5). china has been suffering from serious regional air pollution problems, characterized by high concentrations of surface o3 and pm2.5. in this study, the community multiscale air quality (cmaq) model was use... | sensitivity analysis of the surface ozone and fine particulate matter to meteorological parameters in china |
a well-preserved, ancient delta deposit, in combination with ample exposures of carbonate outcrops, makes jezero crater in nili fossae a compelling astrobiological site. we use compact reconnaissance imaging spectrometer for mars (crism) observations to characterize the surface mineralogy of the crater and surrounding ... | olivine-carbonate mineralogy of the jezero crater region |
pits have been observed on many cometary nuclei mapped by spacecraft. it has been argued that cometary pits are a signature of endogenic activity, rather than impact craters such as those on planetary and asteroid surfaces. impact experiments and models cannot reproduce the shapes of most of the observed cometary pits,... | large heterogeneities in comet 67p as revealed by active pits from sinkhole collapse |
context. in the age of jwst, temperate terrestrial exoplanets transiting nearby late-type m dwarfs provide unique opportunities for characterising their atmospheres, as well as searching for biosignature gases. in this context, the benchmark trappist-1 planetary system has garnered the interest of a broad scientific co... | two temperate super-earths transiting a nearby late-type m dwarf |
atmospheric aerosols scatter or absorb a fraction of the incoming solar radiation to cool or warm the atmosphere, decreasing surface temperature and altering atmospheric stability to further affect the dispersion of air pollutants in the planetary boundary layer (pbl). in the present study, simulations during a persist... | aerosol-radiation feedback deteriorates the wintertime haze in the north china plain |
there is growing observational and theoretical evidence suggesting that atmospheric escape is a key driver of planetary evolution. commonly, planetary evolution models employ simple analytic formulae (e.g. energy limited escape) that are often inaccurate, and more detailed physical models of atmospheric loss usually on... | grid of upper atmosphere models for 1-40 m⊕ planets: application to corot-7 b and hd 219134 b,c |
with the maturation of near-infrared high-resolution spectroscopy, especially when used for precision radial velocity, data reduction has faced unprecedented challenges in terms of how one goes from raw data to calibrated, extracted, and corrected data with required precisions of thousandths of a pixel. here we present... | apero: a pipeline to reduce observations-demonstration with spirou |
previous analyses of mid-infrared water spectra from young protoplanetary disks observed with the spitzer-irs found an anticorrelation between water luminosity and the millimeter dust disk radius observed with alma. this trend was suggested to be evidence for a fundamental process of inner disk water enrichment propose... | jwst reveals excess cool water near the snow line in compact disks, consistent with pebble drift |
circumbinary planets, those that orbit around both stars of a central binary star system, challenge our understanding of planet formation. with only 12 binary systems known to host circumbinary planets, identifying more of these planets, along with their physical properties, could help to discern some of the physical p... | radial-velocity discovery of a second planet in the toi-1338/bebop-1 circumbinary system |
potentially habitable planets can orbit close enough to their host star that the differential gravity across their diameters can produce an elongated shape. frictional forces inside the planet prevent the bulges from aligning perfectly with the host star and result in torques that alter the planet's rotational angular ... | tidal locking of habitable exoplanets |
we address the important question of whether the newly discovered exoplanet, proxima centauri b (pcb), is capable of retaining an atmosphere over long periods of time. this is done by adapting a sophisticated multi-species mhd model originally developed for venus and mars and computing the ion escape losses from pcb. t... | is proxima centauri b habitable? a study of atmospheric loss |
the vera c. rubin observatory is expected to start the legacy survey of space and time (lsst) in early to mid-2025. this multiband wide-field synoptic survey will transform our view of the solar system, with the discovery and monitoring of over five million small bodies. the final survey strategy chosen for lsst has di... | tuning the legacy survey of space and time (lsst) observing strategy for solar system science |
precise estimates of protostellar masses are crucial to characterize the formation of stars of low masses down to brown dwarfs (bds; m * < 0.08 m ☉). the most accurate estimation of protostellar mass uses the keplerian rotation in the circumstellar disk around the protostar. to apply the keplerian rotation method to... | early planet formation in embedded disks (edisk). vi. kinematic structures around the very-low-mass protostar iras 16253-2429 |
we investigate a new class of habitable planets composed of water-rich interiors with massive oceans underlying h2-rich atmospheres, referred to here as hycean worlds. with densities between those of rocky super-earths and more extended mini-neptunes, hycean planets can be optimal candidates in the search for exoplanet... | habitability and biosignatures of hycean worlds |
terrestrial and sub-neptune planets are expected to form in the inner (less than 10 au) regions of protoplanetary disks1. water plays a key role in their formation2-4, although it is yet unclear whether water molecules are formed in situ or transported from the outer disk5,6. so far spitzer space telescope observations... | water in the terrestrial planet-forming zone of the pds 70 disk |
ultra-hot jupiters are tidally locked gas giants with dayside temperatures high enough to dissociate hydrogen and other molecules. their atmospheres are vastly non-uniform in terms of chemistry, temperature, and dynamics, and this makes their high-resolution transmission spectra and cross-correlation signal difficult t... | decomposing the iron cross-correlation signal of the ultra-hot jupiter wasp-76b in transmission using 3d monte carlo radiative transfer |
the last decade of direct imaging (di) searches for sub-stellar companions has uncovered a widely diverse sample that challenges the current formation models, while highlighting the intrinsically low occurrence rate of wide companions, especially at the lower end of the mass distribution. these results clearly show how... | results from the copains pilot survey: four new bds and a high companion detection rate for accelerating stars |
we report the discovery of a circumplanetary disk (cpd) candidate embedded in the circumstellar disk of the t tauri star as 209 at a radial distance of about 200 au (on-sky separation of 1.″4 from the star at a position angle of 161°), isolated via 13co j = 2-1 emission. this is the first instance of cpd detection via ... | molecules with alma at planet-forming scales (maps): a circumplanetary disk candidate in molecular-line emission in the as 209 disk |
discovery of frequent superflares on active cool stars opened a new avenue in understanding the properties of eruptive events and their impact on exoplanetary environments. solar data suggest that coronal mass ejections (cmes) should be associated with superflares on active solar-like planet hosts and produce solar/ste... | extreme energetic particle events by superflare-asssociated cmes from solar-like stars |
on august 25th 2013 dana patchick from the "deep sky hunters" (dsh) amateur astronomer group discovered a diffuse nebulosity in the wide-field infrared survey explorer (wise) mid-ir image archive that had no optical counterpart but appeared similar to many planetary nebulae (pne) in wise. as his 30th discovery he named... | from an amateur pn candidate to the rosetta stone of sn iax research |
scalar fields can give rise to confined structures, such as boson stars or q -balls. these objects are interesting hypothetical new "dark matter stars," but also good descriptions of dark matter haloes when the fields are ultralight. here, we study the dynamical response of such confined bosonic structures when excited... | response of ultralight dark matter to supermassive black holes and binaries |
understanding the origin of volatile element variations in the inner solar system has long been a goal of cosmochemistry, but many early studies searching for the fingerprint of volatile loss using stable isotope systems failed to find any resolvable variations. an improved method for the chemical purification of rb fo... | rubidium isotopic composition of the earth, meteorites, and the moon: evidence for the origin of volatile loss during planetary accretion |
the characterizing exoplanet satellite (cheops) is set to be launched in december 2019 and will detect and characterize small size exoplanets via ultra high precision photometry during transits. cheops is designed as a follow-up telescope and therefore it will monitor a single target at a time. the scientific users wil... | expected performances of the characterising exoplanet satellite (cheops). iii. data reduction pipeline: architecture and simulated performances |
the origin of magnetic fields in white dwarfs remains a fundamental unresolved problem in stellar astrophysics. in particular, the very different fractions of strongly (more than about a megagauss) magnetic white dwarfs in evolutionarily linked populations of close white dwarf binary stars cannot be reproduced by any s... | the origin and evolution of magnetic white dwarfs in close binary stars |
geophysical measurements can reveal the structures and thermal states of icy ocean worlds. the interior density, temperature, sound speed, and electrical conductivity thus characterize their habitability. we explore the variability and correlation of these parameters using 1-d internal structure models. we invoke therm... | geophysical investigations of habitability in ice-covered ocean worlds |
water is a fundamental molecule in the star and planet formation process, essential for catalysing the growth of solid material and the formation of planetesimals within disks1,2. however, the water snowline and the hdo:h2o ratio within proto-planetary disks have not been well characterized because water only sublimate... | deuterium-enriched water ties planet-forming disks to comets and protostars |
context. the james webb space telescope will enable astronomers to obtain exoplanet spectra of unprecedented precision. the miri instrument especially may shed light on the nature of the cloud particles obscuring planetary transmission spectra in the optical and near-infrared.aims: we provide self-consistent atmospheri... | observing transiting planets with jwst. prime targets and their synthetic spectral observations |
context. the total gas mass is one of the most fundamental properties of disks around young stars, because it controls their evolution and their potential to form planets. to measure disk gas masses, co has long been thought to be the best tracer as it is readily detected at (sub)mm wavelengths in many disks. however, ... | co destruction in protoplanetary disk midplanes: inside versus outside the co snow surface |
the mars organic molecule analyzer (moma) instrument onboard the esa/roscosmos exomars rover (to launch in july, 2020) will analyze volatile and refractory organic compounds in martian surface and subsurface sediments. in this study, we describe the design, current status of development, and analytical capabilities of ... | the mars organic molecule analyzer (moma) instrument: characterization of organic material in martian sediments |
breakthrough listen (bl) is a 10 year initiative to search for signatures of technologically capable life beyond earth via radio and optical observations of the local universe. a core part of the bl program is a comprehensive survey of 1702 nearby stars at radio wavelengths (1-10 ghz). here, we report on observations w... | the breakthrough listen search for intelligent life: observations of 1327 nearby stars over 1.10-3.45 ghz |
a key challenge in origins-of-life studies is estimating the abundances of species relevant to the chemical pathways proposed to have contributed to the emergence of life on early earth. dissolved nitrogen oxide anions (nox-), in particular nitrate (no3-) and nitrite (no2-), have been invoked in diverse origins-of-life... | nitrogen oxide concentrations in natural waters on early earth |
observations made during the new horizons flyby provide a detailed snapshot of the current state of pluto's atmosphere. whereas the lower atmosphere (at altitudes of less than 200 kilometers) is consistent with ground-based stellar occultations, the upper atmosphere is much colder and more compact than indicated by pre... | the atmosphere of pluto as observed by new horizons |
transiting exoplanet survey satellite (tess) observations have revealed a compact multiplanet system around the sixth-magnitude star hr 858 (tic 178155732, toi 396), located 32 pc away. three planets, each about twice the size of earth, transit this slightly evolved, late f-type star, which is also a member of a visual... | tess spots a compact system of super-earths around the naked-eye star hr 858 |
we classified the reddest (r - j > 2.2) stars observed by the nasa kepler mission into main-sequence dwarf or evolved giant stars and determined the properties of 4216 m dwarfs based on a comparison of available photometry with that of nearby calibrator stars, as well as available proper motions and spectra. we revi... | they are small worlds after all: revised properties of kepler m dwarf stars and their planets |
the cold classical kuiper belt, a class of small bodies in undisturbed orbits beyond neptune, is composed of primitive objects preserving information about solar system formation. in january 2019, the new horizons spacecraft flew past one of these objects, the 36-kilometer-long contact binary (486958) arrokoth (provisi... | the geology and geophysics of kuiper belt object (486958) arrokoth |
the mechanisms causing millimeter-wave polarization in protoplanetary disks are under debate. to disentangle the polarization mechanisms, we observe the protoplanetary disk around hl tau at 3.1 mm with the atacama large millimeter/submillimeter array (alma), which had the polarization detected with carma at 1.3 mm. we ... | the evidence of radio polarization induced by the radiative grain alignment and self-scattering of dust grains in a protoplanetary disk |
we analyze the k2 light curve of the trappist-1 system. the fourier analysis of the data suggests p rot = 3.295 ± 0.003 days. the light curve shows several flares, of which we analyzed 42 events with integrated flare energies of 1.26 × 1030-1.24 × 1033 erg. approximately 12% of the flares were complex, multi-peaked eru... | frequent flaring in the trappist-1 system—unsuited for life? |
based on 30 year repeated expendable bathythermograph (xbt) deployments between fremantle, western australia, and the sunda strait, indonesia, from 1984 to 2013, interannual variability of geostrophic transport of the indonesian throughflow (itf) and its relationships with el niño southern oscillation (enso) and the in... | interannual variability of the indonesian throughflow transport: a revisit based on 30 year expendable bathythermograph data |
the juno spacecraft reached the mid-point of its nominal mission in december 2018, after completing 17 perijove passes. ten of these were dedicated to the determination of the gravity field of the planet, with the aim of constraining its interior structure. we provide an update on jupiter's gravity field, its tidal res... | jupiter's gravity field halfway through the juno mission |
jupiter is the source of the strongest planetary radio emissions in the solar system. variations in these emissions are symptomatic of the dynamics of jupiter's magnetosphere and some have been directly associated with jupiter's auroras. the strongest radio emissions are associated with io's interaction with jupiter's ... | the juno waves investigation |
using a general circulation model (gcm), we investigate trends in simulated hot jupiter atmospheres for a range of irradiation temperatures (1500-4000 k), surface gravities (10 and 40 m s-2), and cloud conditions. our models include simplified temperature-dependent clouds with radiative feedback and show how different ... | clouds in three-dimensional models of hot jupiters over a wide range of temperatures. i. thermal structures and broadband phase-curve predictions |
to better understand the dynamical mechanism that accounts for the observed lead-lag correlation between the early winter barents-kara sea (bks) sea ice variability and the later winter midlatitude circulation response, a series of experiments are conducted using a simplified atmospheric general circulation model with ... | prolonged effect of the stratospheric pathway in linking barents-kara sea sea ice variability to the midlatitude circulation in a simplified model |
the aerosol-radiation-cloud feedbacks on meteorology and air quality over eastern china under severe winter haze conditions in january 2013 are simulated using the fully coupled online weather research and forecasting/chemistry (wrf-chem) model. three simulation scenarios including different aerosol configurations are ... | simulating aerosol-radiation-cloud feedbacks on meteorology and air quality over eastern china under severe haze conditionsin winter |
in a wide variety of natural and laboratory magnetized plasmas, filaments appear as a result of interchange instability. these convective structures substantially enhance transport in the direction perpendicular to the magnetic field. according to filament models, their propagation may follow different regimes dependin... | experimental validation of a filament transport model in turbulent magnetized plasmas |
the knowledge of the tensile strength of astrophysical dust and ice aggregates is of major importance to understand the early stages of planet formation in our solar system and cometary activity. in this letter, we report on an experimental setup, developed to measure the tensile strength of granular, astrophysical rel... | the tensile strength of ice and dust aggregates and its dependence on particle properties |
we measure wind velocities on opposite sides of the hot jupiter hd 189733b by modeling sodium absorption in high-resolution transmission spectra from the high accuracy radial velocity planet searcher. our model implicitly accounts for the rossiter-mclaughlin effect, which we show can explain the high wind velocities su... | spatially resolved eastward winds and rotation of hd 189733b |
the climate of mars likely evolved from a warmer, wetter early state to the cold, arid current state. however, no solutions for this evolution have previously been found to satisfy the observed geological features and isotopic measurements of the atmosphere. here we show that a family of solutions exist, invoking no mi... | tracing the fate of carbon and the atmospheric evolution of mars |
context. alma observations of protoplanetary disks confirm earlier indications that there is a clear difference between the dust and gas radial extents. the origin of this difference is still debated, with both radial drift of the dust and optical depth effects suggested in the literature.aims: in thermo-chemical model... | different dust and gas radial extents in protoplanetary disks: consistent models of grain growth and co emission |
we present comprehensive orbital analyses and dynamical masses for the substellar companions gl 229 b, gl 758 b, hd 13724 b, hd 19467 b, hd 33632 ab, and hd 72946 b. our dynamical fits incorporate radial velocities, relative astrometry, and, most importantly, calibrated hipparcos-gaia edr3 accelerations. for hd 33632 a... | improved dynamical masses for six brown dwarf companions using hipparcos and gaia edr3 |
studies1,2 have shown that the remnants of destroyed planets and debris-disk planetesimals can survive the volatile evolution of their host stars into white dwarfs3,4, but few intact planetary bodies around white dwarfs have been detected5-8. simulations predict9-11 that planets in jupiter-like orbits around stars of ≲... | a jovian analogue orbiting a white dwarf star |
the near-inrared spectrograph (nirspec) on the james webb space telescope (jwst) is a very versatile instrument, offering mul-tiobject and integral field spectroscopy with varying spectral resolution (~30 to ~3000) over a wide wavelength range from 0.6 to 5.3 micron, enabling scientists to study many science themes ran... | the near-infrared spectrograph (nirspec) on the james webb space telescope. iv. capabilities and predicted performance for exoplanet characterization |
the imaging ultraviolet spectrograph (iuvs) is one of nine science instruments aboard the mars atmosphere and volatile and evolution (maven) spacecraft. maven, launched in november 18, 2013 and arriving at mars in september 2014, is designed to explore the planet's upper atmosphere and ionosphere and examine their inte... | the imaging ultraviolet spectrograph (iuvs) for the maven mission |
the inner moons of jupiter and saturn migrate outwards due to tidal energy dissipation within the planets, the details of which remain poorly understood. we demonstrate that resonance locking between moons and internal oscillation modes of the planet can produce rapid tidal migration. resonance locking arises due to th... | resonance locking as the source of rapid tidal migration in the jupiter and saturn moon systems |
this paper describes the vartools program, which is an open-source command-line utility, written in c, for analyzing astronomical time-series data, especially light curves. the program provides a general-purpose set of tools for processing light curves including signal identification, filtering, light curve manipulatio... | vartools: a program for analyzing astronomical time-series data |
impact craters, which can be considered the lunar equivalent of fossils, are the most dominant lunar surface features and record the history of the solar system. we address the problem of automatic crater detection and age estimation. from initially small numbers of recognized craters and dated craters, i.e., 7895 and ... | lunar impact crater identification and age estimation with chang'e data by deep and transfer learning |
for the last decade, gaussian process regression (gpr) proved to be a competitive machine learning regression algorithm for earth observation applications, with attractive unique properties such as band relevance ranking and uncertainty estimates. more recently, gpr also proved to be a proficient time series processor ... | green lai mapping and cloud gap-filling using gaussian process regression in google earth engine |
during the past five decades, numerical modeling of subduction, one of the most challenging and captivating geodynamic processes, remained in the core of geodynamic research. remarkable progress has been made in terms of both in-depth understanding of different aspects of subduction dynamics and deciphering the diverse... | numerical modeling of subduction: state of the art and future directions |
an improved maximum correlated kurtosis deconvolution (mckd) method based on quantum genetic algorithm (qga) named qga-mckd is proposed, which can be used for gear and bearing compound fault diagnosis. two key parameters, filter length (l) and deconvolution period (t) of mckd, corresponding to each single fault are ada... | application of improved mckd method based on qga in planetary gear compound fault diagnosis |
in a previous study, we analysed the spectra of 230 cool (teff < 9000 k) white dwarfs exhibiting strong metal contamination, measuring abundances for ca, mg, fe and in some cases na, cr, ti, or ni. here, we interpret these abundances in terms of the accretion of debris from extrasolar planetesimals, and infer parent... | cool dz white dwarfs ii: compositions and evolution of old remnant planetary systems |
we show that, for a low-mass planet that orbits its host star within a few tenths of an au (like the majority of the kepler planets), the atmosphere it was able to accumulate while embedded in the protoplanetary disk may not survive unscathed after the disk disperses. this gas envelope, if more massive than a few perce... | atmospheres of low-mass planets: the "boil-off" |
among the available methods for dating stars, gyrochronology is a powerful one because it requires knowledge of only the star's mass and rotation period. gyrochronology relations have previously been calibrated using young clusters, with the sun providing the only age dependence, and are therefore poorly calibrated at ... | calibrating gyrochronology using kepler asteroseismic targets |
over the past two decades, large strides have been made in the field of planet formation. yet fundamental questions remain. here we review our state of understanding of five fundamental bottlenecks in planet formation. these are the following: (1) the structure and evolution of protoplanetary disks; (2) the growth of t... | challenges in planet formation |
during the dawn of chemistry1,2, when the temperature of the young universe had fallen below some 4,000 kelvin, the ions of the light elements produced in big bang nucleosynthesis recombined in reverse order of their ionization potential. with their higher ionization potentials, the helium ions he2+ and he+ were the fi... | astrophysical detection of the helium hydride ion heh+ |
the atmospheric pressure-temperature profiles for transiting giant planets cross a range of chemical transitions. here we show that the particular shapes of these irradiated profiles for warm giant planets below ∼1300 k lead to striking differences in the behavior of nonequilibrium chemistry compared to brown dwarfs of... | beyond equilibrium temperature: how the atmosphere/interior connection affects the onset of methane, ammonia, and clouds in warm transiting giant planets |
context.gaia data release 3 (dr3) provides a wealth of new data products for the astronomical community to exploit, including astrophysical parameters for half a billion stars. in this work, we demonstrate the high quality of these data products and illustrate their use in different astrophysical contexts.aims: we prod... | gaia data release 3. a golden sample of astrophysical parameters |
this paper presents the recent version of the lunar laser ranging (llr) analysis model at the institut für erdmessung (ife), leibniz universität hannover and highlights a few tests of einstein’s theory of gravitation using llr data. investigations related to a possible temporal variation of the gravitational constant, ... | relativistic tests with lunar laser ranging |
mapping canopy photosynthesis in both high spatial and temporal resolution is essential for carbon cycle monitoring in heterogeneous areas. however, well established satellites in sun-synchronous orbits such as sentinel-2, landsat and modis can only provide either high spatial or high temporal resolution but not both. ... | matching high resolution satellite data and flux tower footprints improves their agreement in photosynthesis estimates |
the european component of the joint esa-nasa asteroid impact & deflection assessment (aida) mission has been redesigned from the original version called asteroid impact mission (aim), and is now called hera. the main objectives of aida are twofold: (1) to perform an asteroid deflection test by means of a kinetic im... | european component of the aida mission to a binary asteroid: characterization and interpretation of the impact of the dart mission |
this paper presents a contemporary review of vertical coupling in the atmosphere and ionosphere system induced by internal waves of lower atmospheric origin. atmospheric waves are primarily generated by meteorological processes, possess a broad range of spatial and temporal scales, and can propagate to the upper atmosp... | internal wave coupling processes in earth's atmosphere |
we analyze 5108 afgkm stars with at least five high-precision radial velocity points, as well as gaia and hipparcos astrometric data, utilizing a novel pipeline developed in previous work. we find 914 radial velocity signals with periods longer than 1000 days. around these signals, 167 cold giants and 68 other types of... | 3d selection of 167 substellar companions to nearby stars |
there is an unprecedented array of new satellite technologies with capabilities for advancing our understanding of ecological processes and the changing composition of the earth's biosphere at scales from local plots to the whole planet. we identified 48 instruments and 13 platforms with multiple instruments that are o... | current and near-term advances in earth observation for ecological applications |
remote sensing offers a way to map crop types across large spatio-temporal scales at low costs. however, mapping crop types is challenging in heterogeneous, smallholder farming systems, such as those in india, where field sizes are often smaller than the resolution of historically available imagery. in this study, we e... | using sentinel-1, sentinel-2, and planet imagery to map crop type of smallholder farms |
metal-ion batteries are key enablers in today's transition from fossil fuels to renewable energy for a better planet with ingeniously designed materials being the technology driver. a central question remains how to wisely manipulate atoms to build attractive structural frameworks of better electrodes and electrolytes ... | solid state chemistry for developing better metal-ion batteries |
vibration signals of gearboxes working under time-varying conditions are non-stationary, which causes difficulties to the fault diagnosis. based on the techniques of signal sparse decomposition and order tracking, a novel method is proposed to extract fault features from non-stationary vibration signals of gearboxes. t... | non-stationary vibration feature extraction method based on sparse decomposition and order tracking for gearbox fault diagnosis |
dense fluid metallic hydrogen occupies the interiors of jupiter, saturn, and many extrasolar planets, where pressures reach millions of atmospheres. planetary structure models must describe accurately the transition from the outer molecular envelopes to the interior metallic regions. we report optical measurements of d... | insulator-metal transition in dense fluid deuterium |
exploring the origins and evolution of magnetic fields in planets, stars and galaxies, this book gives a basic introduction to magnetohydrodynamics and surveys the observational data, with particular focus on geomagnetism and solar magnetism. pioneering laboratory experiments that seek to replicate particular aspects o... | self-exciting fluid dynamos |
changes in margins derived from satellite imagery are quantitative indicators of the environmental processes and drivers acting on the earth's surface, for example retreating ice margins or coastal changes with rising sea level. however, the large-scale rapid visualisation and analysis of the satellite record is often ... | the google earth engine digitisation tool (geedit) and the margin change quantification tool (maqit) - simple tools for the rapid mapping and quantification of changing earth surface margins |
an accurate line list, vomyt, of spectroscopic transitions is presented for hot vo. the 13 lowest electronic states are considered. curves and couplings are based on initial ab initio electronic structure calculations and then tuned using available experimental data. dipole moment curves, used to obtain transition inte... | exomol line lists - xviii. the high-temperature spectrum of vo |
atmospheric chemical abundances of giant planets lead to important constraints on planetary formation and migration. studies have shown that giant planets that migrate through the protoplanetary disc can accrete substantial amounts of oxygen-rich planetesimals, leading to supersolar metallicities in the envelope and so... | atmospheric signatures of giant exoplanet formation by pebble accretion |
we perform three-dimensional stratified shearing-box magnetohydrodynamic (mhd) simulations on the gas dynamics of protoplanetary disks with a net vertical magnetic flux of bz0. all three nonideal mhd effects, ohmic resistivity, the hall effect, and ambipolar diffusion, are included in a self-consistent manner based on ... | hall effect controlled gas dynamics in protoplanetary disks. ii. full 3d simulations toward the outer disk |
in this chapter, we review the processes involved in the formation of planetesimals and comets. we will start with a description of the physics of dust grain growth and how this is mediated by gas-dust interactions in planet-forming disks. we will then delve into the various models of planetesimal formation, describing... | comets and planetesimal formation |
the two most intense wildfires of the last decade that took place in canada in 2017 and australia in 2019-2020 were followed by large injections of smoke into the stratosphere due to pyro-convection. after the australian event, khaykin et al. (2020) and kablick et al. (2020) discovered that part of this smoke self-orga... | smoke-charged vortices in the stratosphere generated by wildfires and their behaviour in both hemispheres: comparing australia 2020 to canada 2017 |
aims: we present arcis, a novel code for the analysis of exoplanet transmission and emission spectra. the aim of the modelling framework is to provide a tool able to link observations to physical models of exoplanet atmospheres.methods: the modelling philosophy chosen in this paper is to use physical and chemical model... | the arcis framework for exoplanet atmospheres. modelling philosophy and retrieval |
the global evolution and dispersal of protoplanetary disks (ppds) are governed by disk angular-momentum transport and mass-loss processes. recent numerical studies suggest that angular-momentum transport in the inner region of ppds is largely driven by magnetized disk wind, yet the wind mass-loss rate remains unconstra... | magneto-thermal disk winds from protoplanetary disks |
nasa's messenger spacecraft has revealed geochemical diversity across mercury's volcanic crust. near-infrared to ultraviolet spectra and images have provided evidence for the fe2+-poor nature of silicate minerals, magnesium sulfide minerals in hollows and a darkening component attributed to graphite, but existing spect... | silicate mineralogy at the surface of mercury |
collisions between particles suspended in a fluid play an important role in many physical processes. as an example, collisions of microscopic water droplets in clouds are a necessary step in the production of macroscopic raindrops. collisions of dust grains are also conjectured to be important for planet formation in t... | collisional aggregation due to turbulence |
data on global agricultural production are usually available as statistics at administrative units, which does not give any diversity and spatial patterns; thus they are less informative for subsequent spatially explicit agricultural and environmental analyses. in the second part of the two-paper series, we introduce s... | a cultivated planet in 2010 - part 2: the global gridded agricultural-production maps |
air quality and visibility are strongly influenced by aerosol loading, which is driven by meteorological conditions. the quantification of their relationships is critical to understanding the physical and chemical processes and forecasting of the polluted events. we investigated and quantified the relationship between ... | quantifying the relationship between pm2.5 concentration, visibility and planetary boundary layer height for long-lasting haze and fog-haze mixed events in beijing |
nasa's insight mission to mars will measure seismic signals to determine the planet's interior structure. these highly sensitive seismometers are susceptible to corruption of their measurements by environmental changes. magnetic fields, atmosphere pressure changes, and local winds can all induce apparent changes in the... | insight auxiliary payload sensor suite (apss) |
we present a new transit timing catalog of 2599 kepler objects of interest (kois), using the pdc-map long-cadence light curves that include the full 17 quarters of the mission (ftp://wise-ftp.tau.ac.il/pub/tauttv/ttv/ver_112). the goal is to produce an easy-to-use catalog that can stimulate further analyses of interest... | transit timing observations from kepler. ix. catalog of the full long-cadence data set |
the atacama large millimeter/submillimeter array (alma) has found multiple dust gaps and rings in a number of protoplanetary disks in continuum emission at millimeter wavelengths. the origin of such structures is under debate. recently, we documented how one super-earth planet can open multiple (up to five) dust gaps i... | multiple disk gaps and rings generated by a single super-earth. ii. spacings, depths, and number of gaps, with application to real systems |
context. a terrestrial planet is molten during formation and may remain molten due to intense insolation or tidal forces. observations favour the detection and characterisation of hot planets, potentially with large outgassed atmospheres.aims: we aim to determine the radius of hot earth-like planets with large outgassi... | linking the evolution of terrestrial interiors and an early outgassed atmosphere to astrophysical observations |
absorption lines from water, methane, and carbon monoxide are detected in the atmosphere of exoplanet hr 8799 b. a medium-resolution spectrum presented here shows well-resolved and easily identified spectral features from all three molecules across the k band. the majority of the lines are produced by co and h2o, but s... | simultaneous detection of water, methane, and carbon monoxide in the atmosphere of exoplanet hr8799b |
the observed radii distribution of kepler exoplanets reveals two distinct populations: those that are more likely to be terrestrials (≲1.7r⊕) and those that are more likely to be gas-enveloped (≳2r⊕). there exists a clear gap in the distribution of radii that separates these two kinds of planets. mass-loss processes li... | primordial radius gap and potentially broad core mass distributions of super-earths and sub-neptunes |
enceladus's long-lived plume of ice grains and water vapor makes accessing oceanic material readily achievable from orbit (around saturn or enceladus) and from the moon's surface. in preparation for the national academies of sciences, engineering and medicine 2023-2032 planetary science and astrobiology decadal survey,... | the enceladus orbilander mission concept: balancing return and resources in the search for life |
context. while jupiter's massive gas envelope consists mainly of hydrogen and helium, the key to understanding jupiter's formation and evolution lies in the distribution of the remaining (heavy) elements. before the juno mission, the lack of high-precision gravity harmonics precluded the use of statistical analyses in ... | jupiter's inhomogeneous envelope |
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