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subaqueous and aeolian bedforms are ubiquitous on earth and other planetary environments. however, it is still unclear which hydrodynamic mechanisms lead to the observed variety of morphologies of self-organized natural patterns such as ripples, dunes or compound bedforms. here we present simulations with a coupled hyd... | a unified model of ripples and dunes in water and planetary environments |
context. the solar telescope connected to harps-n has been observing the sun since the summer of 2015. such a high-cadence, long-baseline data set is crucial for understanding spurious radial-velocity signals induced by our sun and by the instrument. on the instrumental side, this data set allowed us to detect sub- m s... | three years of harps-n high-resolution spectroscopy and precise radial velocity data for the sun |
a growing number of initiatives at global, regional and national scales propose to plant millions, billions or even trillions of trees as a simple solution to resolve complex environmental problems. however, tree planting is much more complicated than it seems. we summarize the multifaceted decision‑making process need... | guidance for successful tree planting initiatives |
impact cratering was a dominant geologic process in the early solar system that probably played an active role in the crustal evolution of the young terrestrial planets. the earth's interior during the hadean, 4.56 to 4 billion years ago, may have been too hot to sustain plate tectonics. however, whether large impacts ... | impact-driven subduction on the hadean earth |
oxygen fugacity is a measure of rock oxidation that influences planetary structure and evolution. most rocky bodies in the solar system formed at oxygen fugacities approximately five orders of magnitude higher than a hydrogen-rich gas of solar composition. it is unclear whether this oxidation of rocks in the solar syst... | oxygen fugacities of extrasolar rocks: evidence for an earth-like geochemistry of exoplanets |
groundbased and spacecraft telescopic observations, combined with an intensive modeling effort, have greatly enhanced our understanding of hot giant planets and brown dwarfs over the past ten years. although these objects are all fluid, hydrogen worlds with stratified atmospheres overlying convective interiors, they ex... | atmospheric dynamics of hot giant planets and brown dwarfs |
we present the collection of elemental routines for echelle spectra (ceres). these routines were developed for the construction of automated pipelines for the reduction, extraction, and analysis of spectra acquired with different instruments, allowing the obtention of homogeneous and standardized results. this modular ... | ceres: a set of automated routines for echelle spectra |
the resilience concept requires greater attention to human livelihoods if it is to address the limits to adaptation strategies and the development needs of the planet's poorest and most vulnerable people. although the concept of resilience is increasingly informing research and policy, its transfer from ecological theo... | livelihood resilience in the face of climate change |
co is widely used as a tracer of molecular gas. however, there is now mounting evidence that gas phase carbon is depleted in the disk around tw hya. previous efforts to quantify this depletion have been hampered by uncertainties regarding the radial thermal structure in the disk. here we present resolved alma observati... | the radial distribution of h2 and co in tw hya as revealed by resolved alma observations of co isotopologues |
we present the fargo3d code, recently publicly released. it is a magnetohydrodynamics code developed with special emphasis on the physics of protoplanetary disks and planet-disk interactions, and parallelized with mpi. the hydrodynamics algorithms are based on finite-difference upwind, dimensionally split methods. the ... | fargo3d: a new gpu-oriented mhd code |
we study tidal dissipation in stars with masses in the range 0.1-1.6 m⊙ throughout their evolution, including turbulent effective viscosity acting on equilibrium tides and inertial waves (iws) in convection zones, and internal gravity waves in radiation zones. we consider a range of stellar evolutionary models and inco... | tidal dissipation in evolving low-mass and solar-type stars with predictions for planetary orbital decay |
young stars are surrounded by a circumstellar disk of gas and dust, within which planet formation can occur. gravitational forces in multiple star systems can disrupt the disk. theoretical models predict that if the disk is misaligned with the orbital plane of the stars, the disk should warp and break into precessing r... | a triple-star system with a misaligned and warped circumstellar disk shaped by disk tearing |
emission from protostars at centimeter radio wavelengths has been shown to trace the free-free emission arising from ionizing shocks as a result of jets and outflows driven by protostars. therefore, measuring properties of protostars at radio frequencies can provide valuable insights into the nature of their outflows a... | the vla nascent disk and multiplicity survey of perseus protostars (vandam). iv. free-free emission from protostars: links to infrared properties, outflow tracers, and protostellar disk masses |
exoplanets can evolve significantly between birth and maturity, as their atmospheres, orbits, and structures are shaped by their environment. young planets (<1 gyr) offer an opportunity to probe the critical early stages of this evolution, where planets evolve the fastest. however, most of the known young planets or... | tess hunt for young and maturing exoplanets (thyme). iii. a two-planet system in the 400 myr ursa major group |
the catalog of hierarchical stellar systems with three or more components is an update of the original 1997 version. for 2000 hierarchies, the new multiple star catalog (msc) provides distances, component masses and periods, and supplementary information (astrometry, photometry, identifiers, orbits, notes). the msc con... | the updated multiple star catalog |
in the last few decades the magnitude and impacts of planetary urban transformations have become increasingly evident to scientists and policymakers. the ability to understand these processes remained limited in terms of territorial scope and comparative capacity for a long time: data availability and harmonization wer... | unveiling 25 years of planetary urbanization with remote sensing: perspectives from the global human settlement layer |
we present an update of the open-source photochemical kinetics code vulcan to include c-h-n-o-s networks and photochemistry. the additional new features are advection transport, condensation, various boundary conditions, and temperature-dependent uv cross sections. first, we validate our photochemical model for hot jup... | a comparative study of atmospheric chemistry with vulcan |
the madden-julian oscillation (mjo) is the dominant mode of tropical atmospheric intraseasonal variability and a primary source of predictability for global sub-seasonal prediction. understanding the origin and perpetuation of the mjo has eluded scientists for decades. the present paper starts with a brief review of pr... | a trio-interaction theory for madden-julian oscillation |
reports of methane detection in the martian atmosphere have been intensely debated. the presence of methane could enhance habitability and may even be a signature of life. however, no detection has been confirmed with independent measurements. here, we report a firm detection of 15.5 ± 2.5 ppb by volume of methane in t... | independent confirmation of a methane spike on mars and a source region east of gale crater |
changes in aerosols cause a change in net top-of-the-atmosphere (toa) short-wave and long-wave radiative fluxes; rapid adjustments in clouds, water vapour and temperature; and an effective radiative forcing (erf) of the planetary energy budget. the diverse sources of model uncertainty and the computational cost of runn... | aerosol and physical atmosphere model parameters are both important sources of uncertainty in aerosol erf |
reconstructing the chemical evolution of the milky way is crucial for understanding the formation of stars, planets, and galaxies throughout cosmic time. different studies associated with element production in the early universe and how elements are incorporated into gas and stars are necessary to piece together how th... | jinabase—a database for chemical abundances of metal-poor stars |
tropical forests are crucial for mitigating climate change, but many forests continue to be driven from carbon sinks to sources through human activities. to support more sustainable forest uses, we need to measure and monitor carbon stocks and emissions at high spatial and temporal resolution. we developed the first la... | monitoring tropical forest carbon stocks and emissions using planet satellite data |
transmission spectroscopy is a powerful technique widely used to probe exoplanet terminators. atmospheric retrievals of transmission spectra are enabling comparative studies of exoplanet atmospheres. however, the atmospheric properties inferred by retrieval techniques display a significant anomaly: most retrieved tempe... | why is it so cold in here? explaining the cold temperatures retrieved from transmission spectra of exoplanet atmospheres |
the magnetic white dwarfs (mwds) are found either isolated or in interacting binaries. the isolated mwds divide into two groups: a high field group (105 -109 g) comprising some 13 ± 4 % of all white dwarfs (wds), and a low field group (b <105 g) whose incidence is currently under investigation. the situation may be ... | magnetic fields in isolated and interacting white dwarfs |
the first detection of gas-phase methanol in a protoplanetary disk (tw hya) is presented. in addition to being one of the largest molecules detected in disks to date, methanol is also the first disk organic molecule with an unambiguous ice chemistry origin. the stacked methanol emission, as observed with the atacama la... | first detection of gas-phase methanol in a protoplanetary disk |
based on a climate-chemistry model (constrained by reanalyses below ~50 km), the zonal-mean composite response of the mesosphere and lower thermosphere (mlt) to major sudden stratospheric warming events with elevated stratopauses demonstrates the role of planetary waves (pws) in driving the mean circulation in the pres... | on the composite response of the mlt to major sudden stratospheric warming events with elevated stratopause |
the earth is well known to be, in the current astronomical configuration, in a regime where two asymptotic states can be realized. the warm state we live in is in competition with the ice-covered snowball state. the bistability exists as a result of the positive ice-albedo feedback. in a previous investigation performe... | transitions across melancholia states in a climate model: reconciling the deterministic and stochastic points of view |
oxygen is the most common element after hydrogen and helium in jupiter's atmosphere, and may have been the primary condensable (as water ice) in the protoplanetary disk. prior to the juno mission, in situ measurements of jupiter's water abundance were obtained from the galileo probe, which dropped into a meteorological... | the water abundance in jupiter's equatorial zone |
the nature of the thermal structure of hot jupiter atmospheres is one of the key questions raised by the characterization of transiting exoplanets over the past decade. there have been claims that many hot jupiters exhibit atmospheric thermal inversions. however, these claims have been based on broadband photometry rat... | no thermal inversion and a solar water abundance for the hot jupiter hd 209458b from hst/wfc3 spectroscopy |
our modern day solar system has 4.6 × 109 yr of evolution behind it with just a few relics of its birth conditions remaining. comets are thought to be some of the most pristine tracers of the initial ingredients that were combined to produce the earth and the other planets. other low-mass protostars may be analogous to... | ingredients for solar-like systems: protostar iras 16293-2422 b versus comet 67p/churyumov-gerasimenko |
the trappist-1 system provides an extraordinary opportunity to study multiple terrestrial extrasolar planets and their atmospheres. here, we use the national center for atmospheric research community atmosphere model version 4 to study the possible climate and habitability of the planets in the trappist-1 system. we as... | assessing the habitability of the trappist-1 system using a 3d climate model |
context. circumstellar disks and self-luminous giant exoplanets or companion brown dwarfs can be characterized through direct-imaging polarimetry at near-infrared wavelengths. sphere/irdis at the very large telescope has the capabilities to perform such measurements, but uncalibrated instrumental polarization effects l... | polarimetric imaging mode of vlt/sphere/irdis. ii. characterization and correction of instrumental polarization effects |
we carry out 2d viscous hydrodynamics simulations of circumbinary disk (cbd) accretion using arepo. we resolve the accretion flow from a large-scale cbd down to the streamers and disks around individual binary components. extending our recent studies, we consider circular binaries with various mass ratios (0.1 ≤ qb ≤ 1... | circumbinary accretion from finite and infinite disks |
we report initial results of a large radial velocity survey of k dwarfs up to a distance of 50 pc from the solar system, to look for stellar, brown dwarf, and jovian planets using radial velocities from the chiron spectrograph on the ctio/smarts 1.5 m telescope. we identify three new exoplanet candidates orbiting host ... | the solar neighborhood xlviii: nine giant planets orbiting nearby k dwarfs, and the chiron spectrograph's radial velocity performance |
exoplanet science is one of the most thriving fields of modern astrophysics. a major goal is the atmospheric characterization of dozens of small, terrestrial exoplanets in order to search for signatures in their atmospheres that indicate biological activity, assess their ability to provide conditions for life as we kno... | atmospheric characterization of terrestrial exoplanets in the mid-infrared: biosignatures, habitability, and diversity |
context. atmospheric magnetic fields in stars with convective envelopes heat stellar chromospheres, and thus increase the observed flux in the ca ii h and k doublet. starting with the historical mount wilson monitoring program, these two spectral lines have been widely used to trace stellar magnetic activity, and as a ... | magnetic activity in the harps m dwarf sample. the rotation-activity relationship for very low-mass stars through r'hk |
we report relations between inner (<1 au) super earths (planets with mass/radius between earth and neptune) and outer (>1 au) giant planets (mass > 0.3 m j, or cold jupiters) around sun-like stars, based on data from both ground-based radial velocity (rv) observations and the kepler mission. we find that cold ... | the super earth-cold jupiter relations |
although it is well accepted that the particle size distribution in saturn's rings is not primordial, it remains unclear whether the observed distribution is unique or universal, that is, whether it is determined by the history of the rings and details of the particle interaction or whether the distribution is generic ... | size distribution of particles in saturn's rings from aggregation and fragmentation |
roth et al. (2014a) reported evidence for plumes of water venting from a southern high latitude region on europa: spectroscopic detection of off-limb line emission from the dissociation products of water. here, we present hubble space telescope direct images of europa in the far-ultraviolet (fuv) as it transited the sm... | probing for evidence of plumes on europa with hst/stis |
context. the protoplanetary disk around the f-type star hd 135344b (sao 206462) is in a transition stage and shows many intriguing structures both in scattered light and thermal (sub-)millimeter emission which are possibly related to planet formation processes.aims: we aim to study the morphology and surface brightness... | shadows cast on the transition disk of hd 135344b. multiwavelength vlt/sphere polarimetric differential imaging |
we present an atmospheric transmission spectrum for the ultra-hot jupiter wasp-121b, measured using the space telescope imaging spectrograph on board the hubble space telescope. across the 0.47-1 μ {{m}} wavelength range, the data imply an atmospheric opacity comparable to—and in some spectroscopic channels exceeding—t... | an optical transmission spectrum for the ultra-hot jupiter wasp-121b measured with the hubble space telescope |
we present results from the weather on other worlds spitzer exploration science program to investigate photometric variability in l and t dwarfs, usually attributed to patchy clouds. we surveyed 44 l3-t8 dwarfs, spanning a range of j - ks colors and surface gravities. we find that 14/23 (61%-20%+17%, 95% confidence) of... | weather on other worlds. ii. survey results: spots are ubiquitous on l and t dwarfs |
a new hot line list for 14nh3 is presented. the line list coyute was constructed using an accurate, empirically refined potential energy surface and a ccsd(t)/aug-cc-pvqz ab initio dipole moment surface of ammonia, previously reported. the line list is an improvement of the ammonia line list byte. the coyute line list ... | exomol molecular line lists - xxxv. a rotation-vibration line list for hot ammonia |
precise atmospheric observations have been made for a growing sample of warm neptunes. here, we investigate the correlations between these observations and a large number of system parameters to show that, at 95% confidence, the amplitude of a warm neptune's spectral features in transmission correlates with either its ... | trends in atmospheric properties of neptune-size exoplanets |
astronomical observations reveal that protoplanetary disks around young stars commonly have ring- and gap-like structures in their dust distributions. these features are associated with pressure bumps trapping dust particles at specific locations, which simulations show are ideal sites for planetesimal formation. here ... | planetesimal rings as the cause of the solar system's planetary architecture |
we demonstrate that the deep volatile storage capacity of magma oceans has significant implications for the bulk composition, interior, and climate state inferred from exoplanet mass and radius data. experimental petrology provides the fundamental properties of the ability of water and melt to mix. so far, these data h... | hidden water in magma ocean exoplanets |
accurate knowledge of the location and magnitude of ocean heat content (ohc) variability and change is essential for understanding the processes that govern decadal variations in surface temperature, quantifying changes in the planetary energy budget, and developing constraints on the transient climate response to exte... | ocean heat content variability and change in an ensemble of ocean reanalyses |
the eurodelta iii exercise has facilitated a comprehensive intercomparison and evaluation of chemistry transport model performances. participating models performed calculations for four 1-month periods in different seasons in the years 2006 to 2009, allowing the influence of different meteorological conditions on model... | presentation of the eurodelta iii intercomparison exercise - evaluation of the chemistry transport models' performance on criteria pollutants and joint analysis with meteorology |
the origin of cometary matter and the potential contribution of comets to inner-planet atmospheres are long-standing problems. during a series of dedicated low-altitude orbits, the rosetta orbiter spectrometer for ion and neutral analysis (rosina) on the rosetta spacecraft analyzed the isotopes of xenon in the coma of ... | xenon isotopes in 67p/churyumov-gerasimenko show that comets contributed to earth's atmosphere |
recent observations of ultra-hot jupiters with dayside temperatures in excess of 2500 k have found evidence for new physical processes at play in their atmospheres. in this work, we investigate the effects of the dissociation of molecular hydrogen and recombination of atomic hydrogen on the atmospheric circulation of u... | the atmospheric circulation of ultra-hot jupiters |
the observed trend in earth's energy imbalance (teei), a measure of the acceleration of heat uptake by the planet, is a fundamental indicator of perturbations to climate. satellite observations (2001-2020) reveal a significant positive globally-averaged teei of 0.38 ± 0.24 wm−2decade−1, but the contributing drivers hav... | anthropogenic forcing and response yield observed positive trend in earth's energy imbalance |
the temperature of ancient oceans is an important constraint for understanding the climate history of our planet. the classical oxygen isotope paleothermometry on fossil shells, while very proficient when applied to the younger (cenozoic) portion of the geologic record, is believed to yield only unreliable results for ... | temperatures and oxygen isotopic composition of phanerozoic oceans |
we present a combined, homogenized analysis of archival submillimeter array (sma) and atacama large millimeter/submillimeter array (alma) observations of the spatially resolved 340 ghz (870 μm) continuum emission from 105 nearby protoplanetary disks. building on the previous sma survey, we infer surface brightness prof... | scaling relations associated with millimeter continuum sizes in protoplanetary disks |
the nancy grace roman space telescope (roman) will perform a galactic exoplanet survey (rges) to discover bound exoplanets with semimajor axes greater than 1 au using gravitational microlensing. roman will even be sensitive to planetary-mass objects that are not gravitationally bound to any host star. such free-floatin... | predictions of the nancy grace roman space telescope galactic exoplanet survey. ii. free-floating planet detection rates |
the new horizons spacecraft mapped colors and infrared spectra across the encounter hemispheres of pluto and charon. the volatile methane, carbon monoxide, and nitrogen ices that dominate pluto’s surface have complicated spatial distributions resulting from sublimation, condensation, and glacial flow acting over season... | surface compositions across pluto and charon |
it is widely held that the first step in forming gas-giant planets, such as jupiter and saturn, was the production of solid `cores' each with a mass roughly ten times that of the earth. getting the cores to form before the solar nebula dissipates (in about one to ten million years; ref. 3) has been a major challenge fo... | growing the gas-giant planets by the gradual accumulation of pebbles |
wasp-39b is a hot saturn-mass exoplanet with a predicted clear atmosphere based on observations in the optical and infrared. here, we complete the transmission spectrum of the atmosphere with observations in the near-infrared (nir) over three water absorption features with the hubble space telescope (hst) wide field ca... | the complete transmission spectrum of wasp-39b with a precise water constraint |
most near-earth objects came from the asteroid belt and drifted via non-gravitational thermal forces into resonant escape routes that, in turn, pushed them onto planet-crossing orbits. models predict that numerous asteroids should be found on orbits that closely approach the sun, but few have been seen. in addition, ev... | super-catastrophic disruption of asteroids at small perihelion distances |
the period versus mass diagrams (i.e., rotational sequences) of open clusters provide crucial constraints for angular momentum evolution studies. however, their memberships are often heavily contaminated by field stars, which could potentially bias the interpretations. in this paper, we use data from gaia dr2 to reasse... | stellar rotation in the gaia era: revised open clusters' sequences |
early mars climate research has well-defined goals (mepag 2018). achieving these goals requires geologists and climate modelers to coordinate. coordination is easier if results are expressed in terms of well-defined parameters. key parameters include the following quantitative geologic constraints. (1) cumulative post-... | geologic constraints on early mars climate |
mars once supported globally-distributed river systems; these flowed more recently and more intensely than previously thought.mars is dry today, but numerous precipitation-fed paleo-rivers are found across the planet's surface. these rivers' existence is a challenge to models of planetary climate evolution. we report r... | persistence of intense, climate-driven runoff late in mars history |
using 16 cmip5/6 models with a spontaneously generated quasi-biennial oscillation (qbo)-like phenomenon, this study investigates the impact of the qbo on the northern winter stratosphere. eight of the models simulate a qbo with a period similar to that observed (25-31 months), with other models simulating a qbo period ... | impact of the quasi-biennial oscillation on the northern winter stratospheric polar vortex in cmip5/6 models |
aims: we investigate the evolution of protoplanetary discs (ppds) with magnetically driven disc winds and viscous heating.methods: we considered an initially massive disc with 0.1 m⊙ to track the evolution from the early stage of ppds. we solved the time evolution of surface density and temperature by taking into accou... | evolution of protoplanetary discs with magnetically driven disc winds |
we present a primary transit observation for the ultra-hot (t eq ∼ 2400 k) gas giant expolanet wasp-121b, made using the hubble space telescope wide field camera 3 in spectroscopic mode across the 1.12-1.64 μm wavelength range. the 1.4 μm water absorption band is detected at high confidence (5.4σ) in the planetary atmo... | detection of h2o and evidence for tio/vo in an ultra-hot exoplanet atmosphere |
we present jwst-miri medium resolution spectrometer (mrs) spectra of the protoplanetary disk around the low-mass t tauri star gw lup from the miri mid-infrared disk survey guaranteed time observations program. emission from 12co2, 13co2, h2o, hcn, c2h2, and oh is identified with 13co2 being detected for the first time ... | minds. the detection of 13co2 with jwst-miri indicates abundant co2 in a protoplanetary disk |
we present initial observations of the interstellar body 2i/(2019 q4) borisov taken to determine its nature prior to the perihelion in 2019 december. images from the nordic optical telescope show a prominent, morphologically stable dust coma and tail. the dust cross-section within 15,000 km of the nucleus averages 130 ... | initial characterization of interstellar comet 2i/2019 q4 (borisov) |
we present a prediction of the transiting exoplanet yield of the tess primary mission, in order to guide follow-up observations and science projects utilizing tess discoveries. our new simulations differ from previous work by using (1) an updated photometric noise model that accounts for the nominal pointing jitter est... | expected yields of planet discoveries from the tess primary and extended missions |
the fact that ocean currents must flow parallel to the coast leads to the dynamics of coastal sea level being quite different from the dynamics in the open ocean. the coastal influence of open-ocean dynamics (dynamics associated with forcing which occurs in deep water, beyond the continental slope) therefore involves a... | sea level and the role of coastal trapped waves in mediating the influence of the open ocean on the coast |
geological sources of h2 and abiotic ch4 have had a critical role in the evolution of our planet and the development of life and sustainability of the deep subsurface biosphere. yet the origins of these sources are largely unconstrained. hydration of mantle rocks, or serpentinization, is widely recognized to produce h2... | subduction hides high-pressure sources of energy that may feed the deep subsurface biosphere |
china's chang'e-5 (ce-5) mission, the first lunar sample return mission since 1976, landed at 43.06°n, 51.92°w on dec. 1, 2020, in northern oceanus procellarum. ce-5 targeted a mare plain (em4/p58) composed of distinctive young (∼1.6-1.7 ga) moderate-ti mare basalts, with elevated th abundance (inherent or extraneous).... | china's chang'e-5 landing site: geology, stratigraphy, and provenance of materials |
the present study investigated dominant characteristics of autumn arctic sea ice concentration (sic) interannual variations and impacts of september-october (so) mean sic anomalies in the east siberian-chukchi-beaufort (escb) seas on winter eurasian climate variability. results showed that the decreased so escb sea ice... | dominant characteristics of early autumn arctic sea ice variability and its impact on winter eurasian climate |
proxima centauri b provides an unprecedented opportunity to understand the evolution and nature of terrestrial planets orbiting m dwarfs. although proxima cen b orbits within its star's habitable zone, multiple plausible evolutionary paths could have generated different environments that may or may not be habitable. he... | the habitability of proxima centauri b: environmental states and observational discriminants |
many parameters constraining the spectral appearance of exoplanets are still poorly understood. we therefore study the properties of irradiated exoplanet atmospheres over a wide parameter range including metallicity, c/o ratio, and host spectral type. we calculate a grid of 1d radiative-convective atmospheres and emiss... | model atmospheres of irradiated exoplanets: the influence of stellar parameters, metallicity, and the c/o ratio |
characterizing the atmospheres of extrasolar planets is the new frontier in exoplanetary science. the last two decades of exoplanet discoveries have revealed that exoplanets are very common and extremely diverse in their orbital and bulk properties. we now enter a new era as we begin to investigate the chemical diversi... | exoplanetary atmospheres—chemistry, formation conditions, and habitability |
we solve the equations of two-dimensional hydrodynamics describing a circumbinary disk accreting onto an eccentric, equal-mass binary. we compute the time rate of change of the binary semimajor axis a and eccentricity e over a continuous range of eccentricities spanning e = 0 to e = 0.9. we find that binaries with init... | orbital evolution of equal-mass eccentric binaries due to a gas disk: eccentric inspirals and circular outspirals |
very recently, spitler et al. and scholz et al. reported their detections of 16 additional bright bursts in the direction of the fast radio burst (frb) 121102. this repeating frb is inconsistent with all of the catastrophic event models put forward previously for hypothetically non-repeating frbs. here, we propose a di... | repeating fast radio bursts from highly magnetized pulsars traveling through asteroid belts |
context. the nearest stars provide a fundamental constraint for our understanding of stellar physics and the galaxy. the nearby sample serves as an anchor where all objects can be seen and understood with precise data. this work is triggered by the most recent data release of the astrometric space mission gaia and uses... | the 10 parsec sample in the gaia era |
the arctic is one of the most rapidly changing places on earth and it is a sentinel region for understanding the range and magnitude of planetary changes, and their impacts on ecosystems. however, our understanding of arctic coastal ecosystems remains limited, and the impacts of ongoing and future climate change on the... | arctic kelp forests: diversity, resilience and future |
venus is earth's twin in size and radiogenic heat budget, yet it remains unclear how venus loses its heat absent plate tectonics. most venusian stagnant-lid models predict a thick lithosphere with heat flow about half that of earth's mobile-lid regime. here we estimate elastic lithospheric thickness at 75 locations on ... | earth-like lithospheric thickness and heat flow on venus consistent with active rifting |
the planetary gearbox is a key transmission apparatus used to change speed and torque. the planetary gear is one of the most failure-prone components in a planetary gearbox. due to the complexity of working environments, collected vibration signals contain a lot of noise and interference; fault characteristic frequenci... | fault diagnosis of planetary gears based on intrinsic feature extraction and deep transfer learning |
in ecosystems, the efficiency of energy transfer from resources to consumers determines the biomass structure of food webs. as a general rule, about 10% of the energy produced in one trophic level makes it up to the next1-3. recent theory suggests that this energy transfer could be further constrained if rising tempera... | warming impairs trophic transfer efficiency in a long-term field experiment |
orbitize! is an open-source, object-oriented software package for fitting the orbits of directly imaged objects. it packages the orbits for the impatient (ofti) algorithm and a parallel-tempered markov chain monte carlo (mcmc) algorithm into a consistent and intuitive python api. orbitize! makes it easy to run standard... | orbitize!: a comprehensive orbit-fitting software package for the high-contrast imaging community |
since the beginning of robotic interplanetary exploration nearly six decades ago, successful atmospheric entry has been accomplished at venus, earth, mars, jupiter, and titan. more entry probe missions are planned to venus, titan, and uranus in the next decade. atmospheric entry subjects the vehicle to rapid decelerati... | planetary entry probe dataset: analysis and rules of thumb for future missions |
kepler-93b is a 1.478 ± 0.019 r ⊕ planet with a 4.7 day period around a bright (v = 10.2), astroseismically characterized host star with a mass of 0.911 ± 0.033 m ⊙ and a radius of 0.919 ± 0.011 r ⊙. based on 86 radial velocity observations obtained with the harps-n spectrograph on the telescopio nazionale galileo and ... | the mass of kepler-93b and the composition of terrestrial planets |
aims: the composition of planetary solids and gases is largely rooted in the processing of volatile elements in protoplanetary disks. to shed light on the key processes, we carry out a comparative analysis of the gas-phase carbon abundance in two systems with a similar age and disk mass, but different central stars: hd... | volatile-carbon locking and release in protoplanetary disks. a study of tw hya and hd 100546 |
planet-forming disks are not isolated systems. their interaction with the surrounding medium affects their mass budget and chemical content. in the context of the alma-dot program, we obtained high-resolution maps of assorted lines from six disks that are still partly embedded in their natal envelope. in this work, we ... | alma chemical survey of disk-outflow sources in taurus (alma-dot). vi. accretion shocks in the disk of dg tau and hl tau |
we present the wide field slitless spectroscopy mode of the niriss instrument on the james webb space telescope. this mode employs two orthogonal low-resolution (resolving power ≈150) grisms in combination with a set of six blocking filters in the wavelength range 0.8-2.3 μm to provide a spectrum of almost every source... | the near-infrared imager and slitless spectrograph for the james webb space telescope. ii. wide field slitless spectroscopy |
our understanding of planetary systems different to our own has grown dramatically in the past 30 yr. however, our efforts to ascertain the degree to which the solar system is abnormal or unique have been hindered by the observational biases inherent to the methods that have yielded the greatest exoplanet hauls. on the... | cool jupiters greatly outnumber their toasty siblings: occurrence rates from the anglo-australian planet search |
jupiter's bright persistent polar aurora and earth's dark polar region indicate that the planets' magnetospheric topologies are very different. high-resolution global simulations show that the reconnection rate at the interface between the interplanetary and jovian magnetic fields is too slow to generate a magnetically... | how jupiter's unusual magnetospheric topology structures its aurora |
a major obstacle to detecting and characterizing long-period, low-mass exoplanets is the intrinsic radial-velocity (rv) variability of host stars. to better understand rv variability, we estimate disk-averaged rv variations of the sun over its magnetic cycle, from the fe i line observed by sdo/hmi, using a physical mod... | unsigned magnetic flux as a proxy for radial-velocity variations in sun-like stars |
context. β pictoris is arguably one of the most studied stellar systems outside of our own. some 30 yr of observations have revealed a highly-structured circumstellar disk, with rings, belts, and a giant planet: β pictoris b. however very little is known about how this system came into being.aims: our objective is to e... | peering into the formation history of β pictoris b with vlti/gravity long-baseline interferometry |
the internal properties of stars in the red-giant phase undergo significant changes on relatively short timescales. long near-uninterrupted high-precision photometric timeseries observations from dedicated space missions such as corot and kepler have provided seismic inferences of the global and internal properties of ... | giant star seismology |
the new horizons spacecraft’s encounter with the cold classical kuiper belt object (486958) arrokoth (provisional designation 2014 mu69) revealed a contact-binary planetesimal. we investigated how arrokoth formed and found that it is the product of a gentle, low-speed merger in the early solar system. its two lenticula... | the solar nebula origin of (486958) arrokoth, a primordial contact binary in the kuiper belt |
the population of small, close-in exoplanets is bifurcated into super-earths and sub-neptunes. we calculate physically motivated mass-radius relations for sub-neptunes, with rocky cores and h/he-dominated atmospheres, accounting for their thermal evolution, irradiation, and mass loss. for planets ≲10 m ⊕, we find that ... | conclusive evidence for a population of water worlds around m dwarfs remains elusive |
the export of organic carbon from the surface ocean forms the basis of the biological carbon pump, an important planetary carbon flux. typically, only a small fraction of primary productivity (pp) is exported (quantified as the export efficiency: export/pp). here we assemble a global data synthesis to reveal that very ... | drivers of carbon export efficiency in the global ocean |
silicon, being one of the most abundant elements in nature, attracts wide-ranging scientific and technological interest. specifically, in its elemental form, crystals of remarkable purity can be produced. one may assume that this would lead to silicon being well understood, and indeed, this is the case for many ambient... | phase transition lowering in dynamically compressed silicon |
tide-locked planets are planets in which tidal stresses from the host star have spun down the planet's rotation to the point where its length of sidereal day equals its length of year. in a nearly circular orbit, such planets have a permanent dayside and a permanent nightside, leading to extreme heating contrasts. in t... | atmospheric circulation of tide-locked exoplanets |
the most viscous volcanic melts and the largest explosive eruptions on our planet consist of calcalkaline rhyolites. these eruptions have the potential to influence global climate. the eruptive products are commonly very crystal-poor and highly degassed, yet the magma is mostly stored as crystal mushes containing small... | a compositional tipping point governing the mobilization and eruption style of rhyolitic magma |
we examine the effects of the rastall parameter on the behaviour of spherically symmetric static distributions of perfect fluid matter. it was claimed by visser [physics letters b, 782, 83, (2018)] that the rastall proposition is completely equivalent to the einstein theory. while many authors have raised contrary argu... | impact of the rastall parameter on perfect fluid spheres |
observations of exoplanetary systems provide clues about the intrinsic distribution of planetary systems, their architectures, and how they formed. we develop a forward modelling framework for generating populations of planetary systems and `observed' catalogues by simulating the kepler detection pipeline (syssim). we ... | architectures of exoplanetary systems - i. a clustered forward model for exoplanetary systems around kepler's fgk stars |
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