abstract stringlengths 3 192k | title stringlengths 4 857 |
|---|---|
in general, panspermia theory discusses the possibility of the spread of life in the universe. the migration of living organisms between planets is crucial in such a "fertilization" process. this study focuses on one particular case and phase of such migration: the possible material transport between the early earth an... | some remarks about asteroid impact triggered "bioaerosol" escape during a putative microbial exchange between early earth and mars |
a fundamental concept in deformation experiments is the idea that steady state flow laws can be theoretically derived and matched to experimental observations. these flow laws link physical properties like stress and temperature to allow the extrapolation of a material's rheology towards natural deformation conditions.... | revisiting creep of calcite |
for twenty years hot jupiters have been challenging planet formation theories. while in-situ formation has rapidly been rejected, the giant planets migration mechanisms are still not well understood. disc migration is probably the dominant scenario but it cannot explain the observed population of hot jupiters. dynamica... | hot jupiters with companions: results of the long-term coralie survey |
turbulent fluid motions in earth's liquid iron core likely sustain the dynamo generating the large-scale geomagnetic field. the underlying flow, influenced by planetary rotation, buoyancy and magnetic forces, and the geometry of the spherical shell, among other mechanisms, is challenging to model numerically and experi... | planetary core-style rotating convective flows in paraboloidal laboratory experiments |
a key mechanism in the orbital and spin evolution of close proximity bodies is the dissipation caused by the interactions of tidal flows with convection. it is expected that the effective viscosity of this interaction (νe) would depend on the tidal frequency (ω) but to what extent is a matter of debate, particularly in... | interactions of tidal flows and convection: frequency dependence and indications of anti-dissipation |
the late pliocene is the most recent interval in earth's history to sustain global temperatures within the range of warming predicted for the 21st century. published global reconstructions and climate models find an average +2° c summer sst anomaly relative to modern during the 3.3-3.0 ma prism interval, when atmospher... | polar frontal migration in the warm late pliocene: diatom evidence from the wilkes land margin, east antarctic |
at a time when small planets in the habitable zone are found, not all the questions about giant planets have been answered. for example, their formation, migration and evolution are far from being fully understood. in this context, the kepler space mission is providing unprecedented constraints to theories by probing t... | the physical properties of giant exoplanets within 400 days of period |
we have detected a candidate 2.2 jupiter-mass planet around a disk-hosting star in upper scorpius, which, if confirmed, would offer a powerful window into how hot jupiters form and present an exceptional case study for theories of migration. | candidate detection of a hot jupiter around a disked star |
when considering geological processes, multiphase multicomponent reactive transport (mpmcrt), where different chemical species interact with different phases in complex ways, is the rule rather than the exception. therefore, mpmcrt controls a number of important geodynamic and geochemical phenomena, such as melt genera... | a multiphase multicomponent reactive transport formalism for disequilibrium melt-rock processes and geochemical geodynamics |
the nasa k2 mission is using the kepler spacecraft to search for transiting planets in multiple fields along the ecliptic plane. one of the planets detected by k2 is k2-55b, a warm neptune in a short-period orbit (2.8 days) around a late k dwarf. we previously obtained near-infrared spectra from irtf/spex to characteri... | a high mass & low envelope fraction for the warm neptune k2-55b |
tidal dissipation inside giant planets is important for the orbital evolution of their natural satellites. it is conventionally treated by parameterized equilibrium tidal the- ory, in which the tidal torque declines rapidly with distance, and orbital expansion was faster in the past. however, lainey et al. (2017) find ... | cassini can constrain tidal dissipation in saturn |
radial velocity and transit surveys indicate the presence of super earth around half of the main sequence stars regardless of their mass and metallicity. in contrast, the frequency of gas giants is much lower and increases with stellar mass and metallicity. i will show how the emergence of super-earth is a robust proce... | brouwer award lecture: planetary dynamics |
bedforms preserved in the rock record can provide detailed information on the morphologies and hydrodynamics of ancient fluvial systems on earth and other planets. existing process–product relations for bedform preservation assume that fluvial cross strata reflect conditions under which bedforms were equilibrated with ... | field evidence for disequilibrium dynamics in preserved fluvial cross-strata: a record of discharge variability or morphodynamic hierarchy? |
the orbits of exoplanets around their host stars are sometimes found to be misaligned with their host stars' spin axes. this misalignment angle, called the stellar obliquity, reflects both the formation of the planetary system and its subsequent dynamical evolution. for instance, a star with a protoplanetary disk and a... | resonant stellar obliquity excitation with a broken protoplanetary disk |
disturbance-driven soil mixing controls the vertical and horizontal motions of sediment that allow for the mobilization of nutrients that are critical for life, the delivery of sediment to channels, and the form of landscapes on earth and beyond. in particular, understanding the vertical profile of soil diffusivity (so... | a probabilistic physical interpretation of luminescence in soils with applications to sediment tracing and soil mixing. |
introduction. ganymede, jupiter's largest moon, is thought to have a salty subsurface ocean underlying an ice shell and may harbor the conditions to support life. the uppermost crust is mainly comprised of two types of terrain: heavily cratered, dark terrains and bright terrains often characterized by grooves [1]. the ... | multi-frequency radar characterization of ganymede's near-surface |
planets smaller than neptune are ubiquitous in the galaxy and those around m stars constitute the bulk of warm and temperate worlds amenable for detailed atmospheric characterization. in this talk, we present a re-analysis of all the available data on small transiting planets around m dwarfs, refining their masses and ... | an observational test to planet formation theories around low-mass stars |
we present the first optical to infrared (0.3-5.0 micron) transmission spectrum of the ultra-hot jupiter kelt-7b, which orbits a bright (v = 8.54) f-type star. with an equilibrium temperature of ~2048 k, the planet inhabits a parameter space where we can explore current exoplanet atmosphere theories regarding thermal d... | the hubble space telescope pancet program: an optical to infrared transmission spectrum of the hot jupiter kelt-7b |
the four satellite systems in the outer solar system are scientifically lucrative targets for exploration and theoretical investigation as they not only provide numerous constraints on solar system formation hypotheses, but are also themselves the end-state of a miniaturized version of a solar system-scale planet accre... | fragility of the uranian satellite system during the epoch of giant planet migration |
warm jupiters (wjs) - defined here as planets larger than 6 earth radii with orbital periods 8-200 days - are a key missing piece of our planet formation and evolution theory. it is currently debated whether wjs form in situ or undergo disk or high eccentricity tidal migration. these different classes of origin channel... | the eccentricity distribution, occurrence rates, and companions of tess warm jupiters |
one challenge in operating a regional seismic network is to verify the responses of the seismic instrumentation installed in the field. we present procedures for remotely determining the frequency response and sensitivity and their corresponding uncertainties and temporal variation. most bdsn stations include a broadba... | remote determination of the frequency response and sensitivity of seismic instrumentation in the berkeley digital seismic network (bdsn) |
this thesis combines two studies of astrophysical flows in which magnetic fields play a dominant role. the first concerns outflows from compact objects in which plasma is accelerated to highly relativistic speeds by strong, ordered magnetic fields. we generalize the theory of relativistic, ideal magnetohydrodynamic (mh... | magnetized astrophysical flows |
measuring the obliquities of exoplanet-host stars provides invaluable diagnostic information for theories of planetary formation and migration. most of these results have so far been obtained by measuring the rossiter-mclaughlin effect, clearly favoring systems that harbor hot jupiters. while it would be extremely help... | spin-orbit alignment of exoplanet systems: how can asteroseismology help us? |
the number of discovered exoplanets now exceeds 1500, mostly due to the kepler space instrument observations. many of these planet orbit in less than a week around their host stars. this implies that the inward migration of those planets is a basic ingredient of successful theories of planet formation and evolution. se... | 3d spin-orbit angle of kepler-25 and hat-p-7 |
two researchers at the university of chicago have recently developed a new theory to explain an apparent dichotomy in the orbits of planets around cool vs. hot stars. their model proposes that the spins of cool stars are affected when they ingest hot jupiters (hjs) early in their stellar lifetimes. a puzzling dichotomy... | hot-jupiter breakfasts realign stars |
the vast majority of well studied giant-planet systems, including the solar system, are nearly coplanar which implies dissipation within a primordial gas disk. however, intrinsic instability may lead to planet-planet scattering, which often produces non-coplanar, eccentric orbits. planet scattering theories have been d... | kepler-108: a mutually inclined giant planet system |
the dynamical instability of the giant planets and the planetesimal driven migration both have major implications for the crater record of the terrestrial planets and the moon. the crater record can thus provide contraints to the behavior of the planets in the early solar system. here we determine the impact fluxes and... | impact cratering of the terrestrial planets and the moon during the giant planet instability |
ferropericlase is the second most abundant phase of earth's lower mantle and is also considered to be one of the main constituents of the mantles of super-earth exoplanets. since ferropericlase is more ductile compared to silicates (girard et al. 2016), it is expected to control the rheological behavior of mantle aggre... | ab initio investigation of the intercrystalline mechanical behavior of ferropericlase at extreme pressures of planetary mantles |
the now established high abundance of exoplanets around low-mass stars makes them ideal to place constraints on planet formation. here, we compare the latest planet occurrence rates from the radial velocity survey carmenes and harps to a synthetic planet population obtained from the bern model of planet formation and e... | planetary population synthesis around low-mass stars |
it is commonly accepted that exoplanets with orbital periods shorter than one day, also known as ultra-short-period (usp) planets, formed further out within their natal protoplanetary disks before migrating to their current-day orbits via dynamical interactions. one of the most accepted theories suggests a violent scen... | a low-eccentricity migration pathway for a 13-h-period earth analogue in a four-planet system |
a large fraction of known exoplanets have short orbital periods where tidal excitation of waves within the host star causes the planets' orbits to decay. we study the effects of tidal resonance locking, in which the planet locks into resonance with a tidally excited stellar gravity mode, which is supported by buoyancy ... | orbital decay of short-period exoplanets via tidal resonance locking |
protostellar disks (ppds) are the nurseries of planets, and feed the developing protostar itself. recent ground and space-based facilities have studied ppds in unprecedented detail. apart from galactic disks, they are the only astronomical accretion disks that are directly angularly resolved. ppds also offer a wealth o... | protostellar disk winds: confronting observations with theory |
warm, large exoplanets with 10-100 day orbital periods pose a major challenge to our understanding of how planetary systems form and evolve. although high eccentricity tidal migration has been invoked to explain their proximity to their host stars, a handful reside in or near orbital resonance with nearby planets, sugg... | precise characterization of a 2:1 resonant pair: the warm jupiter toi-216c and eccentric warm neptune toi-216b |
the mechanism/s responsible for sediment entrainment by wind and bedform migration on mars are a matter of debate [1]. martian large ripples (lrs) migrate under present-day low pressure conditions and have been interpreted has fluid/wind drag ripples [2] or as bedforms formed by aeolian saltation [3]. an important cons... | global wavelength survey of martian bedforms: methods and preliminary results |
topographic rossby waves (trws) are oscillatory phenomena associated with modulations induced by seabed morphology in the potential vorticity field. these features could be confined to a single layer or could involve the whole water column, and they are controlled by a combination of the bathymetric gradient and the un... | framing topographic rossby waves in the southern adriatic sea |
the intracratonic são francisco basin (e brazil) contains the sedimentary record of multiple basin-cycles younger than 1.8 ga. spanning the states of minas gerais, bahia and tocantins, it is bounded in the west, east and north by brasiliano/pan-african orogenic systems. to the northeast, the basin is limited by a neopr... | deep crustal source for hydrogen and helium gases in the são francisco basin, minas gerais, brazil |
the seven planets orbiting the m dwarf trappist-1 in a compact near-resonant chain offer a unique case to study in planet formation theory. of particular interest is the remarkable flatness of the system, exceeding that of any other known planetary system. we use 3d hydrodynamic simulations to study interactions betwee... | how flat can a planetary system get? the case of trappist-1. |
ultra-short-period planets (usps) with orbital periods of less than 1 day are emerging scientific goals in the field of exoplanets. search and identification of usps require light-curve analysis algorithms such as the box least squares(bls) and the fourier transform (ft) to screen and confirm accurate periodic signals.... | the recent research progress of ultra-short periods exoplanets |
t-tauri stars are late-type pre-main-sequence stars that are gravitationally contracting towards the main sequence. magnetic fields largely dictate the angular momentum evolution of these stars and can affect the formation and migration of planets. thus, characterizing their magnetic fields is critical for testing and ... | magnetic fields and planets of weak-line t tauri stars |
high eccentricity migration is a possible formation channel for hot jupiters. however, in order for it to be consistent with the observed population of planets, tides must circularize the orbits in an efficient manner. a potential mechanism for such rapid circularization is the diffusive growth of the tidally driven pl... | tides in the high-eccentricity migration of hot jupiters: effects of nonlinear mode interaction |
the atmospheric characterisation of multiple exoplanets in the same system can provide a window into the processes that underpinned their formation and evolution. the planetary c/o ratios are of particular interest as they encode information about where the planet formed with respect to different ice lines, but precise... | toi-178: the best laboratory for testing planetary formation theories |
the probability that life (l) has been detected on an exoplanet is p( l | d, c ) = p (d, c | l ) p ( l ) / [ p( d, c | l )p( l ) + p( d, c | not-l )p( not-l )] where p is probability, d is bioindicator data, and c is observational constraints on planetary context. the false-positive probability p( d | c, not-l ) is har... | basic limits on exoplanet biosignature false positives: trickster planets |
quantifying the planetary-scale variations caused by non-migrating tides is a prerequisite for elucidating the connection between tropospheric conditions and thermospheric/ionospheric variability. the icon and cosmic-2 spaceflight missions provide an unprecedented opportunity to characterize non-migrating tides in ther... | disentangling thermospheric and ionospheric signatures in tidal perturbations of column o/n2 derived from far ultraviolet airglow |
the variability of non-migrating tides in the stratosphere is investigated using temperature data from canadian middle atmosphere model (cmam30), era-interim reanalysis and formosa satellite-3 and constellation observing system for meteorology, ionosphere, and climate (formosat-3/cosmic) from 2006 to 2010 using a ±10-d... | short-term variability of non-migrating diurnal tides in the stratosphere from cmam30, era-interim, and formosat-3/cosmic |
it was originally conceived that after protoplanets have acquired sufficient mass to open deep gaps in their natal protoplanetary disks, they cut off the global disk gas flow in their vicinity and their type ii migration is coupled to the viscous evolution of the disk (lin & papaloizou 1986). their mass growth is q... | retention of long-period gas giant planets: understanding type ii migration |
we present keck/kpic (keck planet imager and characterizer) high-resolution (r~30000) k-band spectroscopy of the ultra-hot jupiter wasp-33b. the use of kpic's single-mode fiber greatly improves both blaze and line-spread stabilities, enhancing the cross-correlation detection strength. we perform separate retrievals for... | diurnal variations in the thermal spectrum of wasp-33b |
the possibility of plate tectonics in massive rocky planets is a contentious issue. variable estimations suggested by different studies rely on uncertain mantle properties at very high mantle pressures for which there are no experimental constraints. unlike the previous interpretations, new theoretical studies suggest ... | plate tectonics in massive rocky super-earth planets: a consequence of the dissociation transition of post-perovskite at0.9 tpa |
it is generally accepted that the bodies of the inner solar system have been exposed to similar populations of impactors. we can get a sense of the energy distribution of these impactors for a particular orbit by looking at a relatively simple crater size-frequency distribution model for an airless body such as the moo... | building a theoretical crater size-frequency distribution for venus: a new approach to constrain the age of venusian crustal resurfacing |
dunes are found across the solar system. they arise and evolve because loose sediment is moved by goldilocks winds: those that are fast enough to move grains, but not too fast to suspend grains. the mere presence of dunes on a surface therefore tells us something about that planetary body, and perhaps surprises us wher... | conditions for aeolian transport in the solar system |
'kebun culture' is a distinctive, emergent form of rural sensibility and social‑economic relations in malaysia. as a contribution to theories of 'planetary' or thoroughgoing urbanization, the ethnographic evidence presented in the article illustrate a case of urban annexation of rurality, in which kebun (orchards) are ... | urban annexation of the rural: kebun culture in malaysia |
around 50 worlds beyond our solar system have undergone atmospheric characterization in the last 20 years. despite the incredible diversity of exoplanets studied to date, all these worlds share one common aspect: their planets orbit main sequence stars. until recently, the question of the conditions in planetary atmosp... | under the light of a dead star: revealing the atmospheric composition of a white dwarf planet |
population synthesis studies into planet formation have suggested that distributions consistent with observations can only be reproduced if the actual type i migration timescale is at least an order of magnitude longer than that deduced from linear theories. although past studies considered the effect of the type i mig... | population synthesis of planet formation using a torque formula with dynamic effects |
tess' all-sky survey enables studies of the demographics of exoplanets around stars too rare to have been observed in significant numbers by previous missions, or which were simply ignored by earlier observations. one such class is main sequence a stars, which are relatively rare and were mostly avoided by kepler. meas... | the short-period planetary population of a stars with tess |
hot jupiters (hjs) are short period massive planets that must accumulate the majority of their mass in the outer disc. they may arrive at their current orbits via low eccentricity migration within a disc, or via tidal circularisation during close approach with the host star if a sufficiently high eccentricity can be pr... | the importance of hot jupiters in stellar clusters for understanding planet formation |
can wind-driven accretion modify planetary migration?planetary migration plays an important role in planet formation models and statistics of observed exoplanets. so far, the theory of planetary migration has focused on the interaction of one or more planets with an inviscid or viscously evolving gaseous disk. wind-dri... | effect of wind-driven accretion on planetary migration |
the vast majority of stars are in binaries or higher-order multiple stellar systems. although in recent years a large number of binaries have been proven to host exoplanets, how planet formation proceeds in multiple stellar systems has not been studied yet with the necessary insight from the theoretical standpoint. our... | on dust evolution in planet-forming discs in binary systems |
the origin of close-in giant exoplanets is a long-standing puzzle. planet formation theories suggest that such planets are unlikely to have formed in-situ but instead may have formed at large orbital separations beyond the snow line and migrated inward to their present orbits. two competing hypotheses suggest that the ... | chemical constraints on hot jupiter migration |
theory and past observations have provided evidence that atmospheric tides and other global scale waves may nonlinearly interact to produce additional secondary waves throughout the space-atmosphere interaction region. however, very few studies have investigated the generation region of nonlinearly secondary waves, and... | addressing the question of large-scale nonlinear wave coupling in the space-atmosphere interaction region |
our knowledge on the melting behavior in the deep mantle remains based on a limited number of experimental and theoretical works. today, thanks to (i) availability of very brilliant x-ray synchrotron sources and (ii) improved control of the p-t conditions in the laser-heated diamond anvil cell (lh-dac), the experimenta... | melting of bridgmanite to 135 gpa: toward a coherent model for the melting behavior in the lower mantle |
the origin of hot jupiters is the oldest problem in exoplanetary astronomy. one would think it has been thoroughly investigated. however, because hot jupiters are rare, much of our knowledge comes from the statistical analysis of small samples. while hundreds of hot jupiters have been discovered by transit surveys, the... | how bayes' theorem and machine learning reveal the origin of hot jupiter |
two formation models have been proposed to explain hot jupiters’ tight orbits. these could have migrated inward in a disk (disk migration), or they could have formed via tidal circularization of an orbit made highly eccentric following gravitational interactions with a companion (high-eccentricity migration). i will sh... | evolution of giant planets close to the roche limit |
planets with orbital periods of less than a day present real challenges to theories of planet formation and evolution, and yet numerous objects with periods as short as a few hours have been found. so close to their host stars that some are actively disintegrating, these planets' origins remain unclear, and even modifi... | the superpig search for short period planets in the k2 dataset |
we will present new top-level results from our unprecedented debris disk survey of 100+ stars in near-ir, polarized scattered light with the high-contrast gemini planet imager. this four-year survey is the first of its kind: a uniform probe of young planetary system environments for small dust on solar system-like scal... | polarizing planetary systems: new debris disks resolved on solar system scales by gpies |
a substantial fraction of hot jupiters have orbital inclinations misaligned with respect to the spin axis of their host star. the prevalence of this phenomenon posed a challenge to the conventional formation paradigm, wherein hot jupiters were expected to reach they close-in orbits early in a system's evolution via dis... | exciting stellar obliquities in triple star systems |
we present a detailed chemical abundance analysis of planet-hosting wide binary systems. each of these binary systems consists of two stars with similar spectral types (ranging from g2v - k2v), and in each system, at least one star hosts a giant planet with an orbital pericenter ~< 0.5 au. we examine the photospheri... | constraining planet formation theories with the detailed chemical abundances of planet-hosting wide binary stars |
as the first kind of exoplanet to be discovered, hot jupiters have always been objects of interest. despite being prevalent in radial velocity and ground-based surveys, they were found to be much rarer based on kepler observations. these data show a pile-up at radii of 9-22 rearth and orbital periods of 1-10 days. comp... | the occurrence rate of hot jupiters |
our climate system varies on a wide range of timescales, from seasons to several millions of years. a large part of this variability is internally generated as a result of instabilities of the coupled atmosphere-ocean-ice-carbon cycle system. other modes of variability, such as glacial cycles, are caused by astronomica... | astronomical theory of early human migration (milutin milankovic medal lecture) |
short-period planets have the power to unlock many of the mysteries of planet formation and, fortunately, they are abundant. there is growing evidence that high-eccentricity migration channels are not responsible for all short-period planets; this notion is supported by the recent discovery of k2-33 b, a short-period, ... | observational constraints on planet formation and migration timescales |
kepler-79 d provides a unique opportunity to study the atmosphere of a low-mass low density planet among compact multi-transiting systems. it has the largest estimated atmospheric scale-height for a planet in a known compact system of four or more transiting exoplanets and has the highest expected atmospheric annulus d... | the atmosphere of an extremely low density super-earth mass planet |
recently, anglada et al. (2016) discovered a terrestrial planet proxima b orbiting around proxima centauri in the habitable zone, with the semi-major axis of about 0.05 au and a possible eccentricity less than 0.35. proxima centauri is the sun's closest neighbor at present, therefore, proxima b will provide good opport... | tidal evolution and formation for proxima b |
toi-1130 joins wasp-47 and kepler 730 as the only known systems to host hot jupiters with a small inner companion. this apparent scarcity is broadly in line with the hypothesis that most hot jupiters form beyond the ice line and move inwards via high-eccentricity migration (hem). however, statistical evidence based on ... | a new tess discovery refines the occurrence rate of inner companions to hot jupiters |
numerous recent theories of terrestrial planet formation suggest that, in order to reproduce the observed large earth to mars mass ratio, planets formed from an annulus of material within 1 au. the success of these models typically rely on a mars sized embryo being scattered outside 1 au (to ~1.5 au) and starving, whil... | terrestrial planet formation from an annulus -- revisited |
the periglacial areas of the european alps are characterised by rugged peaks and steep rockwalls with adjacent scree slopes that reflect high rates of rockfall activity. the current state of knowledge regards ice segregation as the dominant mechanism responsible for the disintegration of rock and associated destabiliza... | modelling frost weathering processes and related stresses in alpine rockwalls |
extreme-mass-ratio inspirals (emris) are binary systems in which a small compact object orbits into a supermassive black hole. they are primary targets for the planned lisa mission, since the precision of their measured parameters allows for unparalleled tests of general relativity, as well as astrophysical and cosmolo... | measuring accretion-disk effects with extreme-mass-ratio inspirals |
the increasing number of well characterised low-mass planets, combined with the valuable informations from stellar and planetary spectroscopy, opens the way to the modeling of planetary structures and compositions, which can be obtained with theoretical and numerical works. this approach gives a valuable insight to und... | characterising the interior structures and atmospheres of multiplanetary systems. |
a leading theoretical expectation for the final stages of planet formation is that disk migration should naturally drive orbits into chains of mean motion resonances (mmrs). in order to explain the dearth of mmr chains observed at gyr ages (<1%), this picture requires such configurations to destabilize and scramble ... | stability constrained characterization of the 23 myr-old v1298 tau system: do young planets form in mean motion resonance chains? |
it is commonly accepted that exoplanets with orbital periods shorter than 1 day, also known as ultra-short period (usp) planets, formed further out within their natal protoplanetary disk, before migrating to their current-day orbits via dynamical interactions. one of the most accepted theories suggests a violent scenar... | a low-eccentric migration pathway for a 13-hour period earth analog in a four-planet system |
we calculate the upper bounds of the estimated population on theoretically stable centaur orbits between uranus and neptune. these small bodies are on low-eccentricity, low-inclination orbits in two specific bands of semi-major axis, centred at ~24.6~au and ~25.6~au. they exhibit unusually long gyr-stable lifetimes in ... | ossos: xxvi. population estimates for theoretically stable centaurs between uranus and neptune |
the world meets poly crises in climate, pandemic, energy, food, human rights, and migration; hot and cold wars have come in europe and other regions. the scope of the tasks becomes unprecedented, and their complexity demands high-level skill sets and teaching culture. education moves into epicentres of the fight for be... | high-quality education for better sustainability and resiliency |
the martian ionospheric peak is dominated by photochemical processes at dayside. its primary variations can be well described by the chapman theory; nevertheless, deviation still exists between observation and the theory. some factors may be responsible for that deviation, in which the variable upper atmosphere is an i... | evaluation for effects of variable martian upper atmosphere on ionospheric peak electron density based on the mgs ro observation |
a complex myriad of physical processes contribute to the planet formation, likely including collisional growth of solids, particle aggregation in pressure bumps, non-linear solid growth, rapid gas accretion onto critical cores, and subsequent orbital migration. while a tremendous amount of information has been gathered... | yso imaging |
have you ever wondered what springtime is like on saturns largest moon, titan? a team of researchers has analyzed a decade of data from the cassini spacecraft to determine how titans gradual progression through seasons has affected its temperatures.observing the saturn systemthough titan orbits saturn once every ~16 da... | witnessing springtime on titan |
what sets the radius of a planet? even at a given mass and equilibrium temperature, gas giants have a broad spread in radius, and it is unclear under which circumstances thermal evolution; migrational and mass-loss history; or composition is the dominant controller of a planet's radius. studies of individual planet atm... | the twin paradox: assessing planetary radius evolution with a ch4 thermometer |
theoretical works of planetary system formation and their early evolution predict the existence of co-orbital planets (two planets sharing the same orbital period) with occurrence rates up to 30% in multi-planetary systems. trapped either in the lagrangian points of more massive planets or in other type of 1:1 mean mot... | troy: surveying a new type of extreme planetary systems |
during the early stages of planetary system evolution, convergent migration of planet pairs typically leads to capture into resonance, provided that the dissipative resonance-crossing time is long compared with the libration timescale. in light of this, it is unclear why multi-transiting planetary systems found by the ... | migration of two massive planets into (and out of) first order resonances |
from wispy gas giants on the verge of disruption to tiny rocky bodies already falling apart, short-period exoplanets pose a severe puzzle to theories of planet formation and orbital evolution. by far most of the planets known beyond the solar system orbit their stars in much tighter orbits than the most close-in planet... | investigating planet formation and evolutionary processes with short-period exoplanets |
protoplanetary discs are the fundamental channel to peer into both star formation and planet formation: their study through the combination of theory, observations and numerical simulations is essential to unveil still unanswered questions about their structure and the processes that rule them. alma and sphere are amon... | circumstellar dust distribution in systems with two planets in resonance |
over the past two decades ongoing radial velocity and transit surveys have been astoundingly successful in detecting thousands of new planetary systems around nearby stars. these systems include apparently single gas giant planets on short period orbits, closely packed systems of up to 5-6 “super-earths”, and relativel... | the elephant in the room: effects of distant, massive companions on planetary system architectures |
we propose targeted radial velocity (rv) measurements of kepler's high multiplicity systems to search for massive non-transiting planets beyond the known planets in compact formation. this proposal will address a high profile debate in planet formation theory that has been stimulated by the kepler mission, whether mult... | giants beyond the warm neptunes: a survey of outer planetary system architectures amongst kepler's high multiplicity transiting systems |
in spite of steady advances, planet formation remains, by and large, a mystery. although a relatively consistent theory has been developed in the past two decades, its application to the observed distribution of exoplanets has not fared too well. if the statistics of discovered exoplanets suggest that planets form effi... | origin of hot super-earths and the vortex-assisted mode of planet formation. |
reduced-order numerical models of meandering river dynamics generally assume a transverse bed slope that is primarily a function of planform curvature. this assumption is theoretically based on a mobile bed dynamic equilibrium condition that develops when bed processes occur at a much faster rate than bank processes. i... | dependence of channel migration rate on the channel migration rate in meander bends with noncohesive banks |
the story of dan's role in the formulation of the theory of plate tectonics has been told often (see e.g. articles in oreskes, 20011) and i will not repeat that story here. following the establishment of plate tectonics, there were two outstanding issues: what was the driving mechanism that made the plates move? how do... | dan mckenzie: what happened after plate tectonics? |
the fundamental theoretical developments in the field of planet formation and orbital evolution that were pioneered by bill ward will be reviewed. the areas covered range from how particles accumulate to form planetesimals to delineating how protoplanetary cores migrate in the protoplanetary disk. in the latter case he... | bill ward's contributions to planet formation and migration |
the modality of disc dispersal is thought to be of fundamental importance to planet formation, yet the responsible mechanism is still largely unconstrained. photoevaporation from the central star is currently a promising avenue to investigate, but the models developed to date do not yet have enough predictive power for... | the dispersal of planet-forming discs. a new generation of x-ray photoevaporation models |
the recent haul of hundreds of multiple planet systems discovered by kepler provides a treasure trove of new clues for planet formation theories. the substantial amount of protoplanetary disk mass needed to form the most commonly observed multi-planet systems - small (earth-sized to mini-neptune-sized) planets close to... | constraints on planet formation from kepler’s multiple planet systems |
the kepler-36 system comprises two exoplanets: an inner terrestrial super-earth (4.5 me) and an outer gaseous sub-neptune (8.1 me). both planets are orbiting very close to their host star (0.12 and 0.13 au away) and to each other. their orbital periods are in nearly a 7:6 ratio, a mean-motion resonance that is not usua... | on the origin of the kepler-36 system |
boley et al (2010) and nayakshin (2010) proposed tidal downsizing (td), a new hypothesis for forming all types of planets. gas fragments born by gravitational disc instability at ~ 100 au migrate inwards rapidly, with some becoming hot jupiters. grain sedimentation inside the fragments makes rocky cores. these cores ar... | observations vs theory: from metallicity correlations of exoplanets and debris discs to hl tau |
nearly half of all solar-type stars have at least one stellar companion, and planets around g- and k-type stars appear to be quite common. yet the impact of stellar multiplicity on planets is not yet well understood. stellar companions may truncate disks and destabilize planetary orbits, and may contribute to planet mi... | understanding the impacts of stellar companions on planet formation and evolution: a survey of stellar and planetary companions within 25 pc |
objectives: a major and lasting scientific contribution of the prime kepler mission (2009-2013) is the sample of over 4000 planet candidates having orbital periods extending out to <1 year. this distribution encodes key aspects of planet formation physics including the growth of solid cores, accretion of gas, photoe... | the formation and erosion of small planet cores and envelopes: exploring planet occurrence as a function of stellar mass and metallicity |
tides in uranus control how fast its satellites migrate outwards, and how much heating they experience as they pass through orbital resonances. conversely, estimates of satellite heating rates based on geophysical techniques can be used to probe the internal evolution of uranus. satellite orbital evolution is tradition... | uranian satellite characteristics as indicators of the internal evolution of uranus |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.