Latest in astro-ph.ep

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Low albedos of hot to ultra-hot Jupiters in the optical to near-infrared transition regimeFeb 21 2019The depth of a secondary eclipse contains information of both the thermally emitted light component of a hot Jupiter and the reflected light component. If the dayside atmosphere of the planet is assumed to be isothermal, it is possible to disentangle ... More
The equilibrium size-frequency distribution of small craters reveals the effects of distal ejecta on lunar landscape morphologyFeb 20 2019Small craters of the lunar maria are observed to be in a state of equilibrium, in which the rate of production of new craters is, on average, equal to the rate of destruction of old craters. Crater counts of multiple lunar terrains over decades consistently ... More
Ultra-Stable Environment Control for the NEID Spectrometer: Design and Performance DemonstrationFeb 20 2019Two key areas of emphasis in contemporary experimental exoplanet science are the detailed characterization of transiting terrestrial planets, and the search for Earth analog planets to be targeted by future imaging missions. Both of these pursuits are ... More
Discovery of a directly imaged disk in scattered light around the Sco-Cen member Wray 15-788Feb 20 2019As part of our on-going survey we have carried out high-contrast imaging with VLT/SPHERE/IRDIS to obtain polarized and total intensity images of the young ($11^{+16}_{-7}$Myr old) K3IV star Wray 15-788 within the Lower Centaurus Crux subgroup of Sco-Cen. ... More
A highly structured disk around the planet host PDS 70 revealed by high-angular resolution observations with ALMAFeb 20 2019PDS 70b is the most robustly detected young planet imaged in the gap of a transition disk so far, found at a separation of ~195 mas (~22 au) from its host star and at a position angle of about 155 deg. This system is therefore a unique laboratory to characterize ... More
A census of $ρ$-Oph candidate members from \gaia DR2Feb 20 2019Rho-Ophiuchus (Rho-Oph), one of the nearest star forming regions, is an ideal laboratory to study the earlier stages of the stellar and protoplanetary disc evolution. We aim to find potential new members of the Rho-Oph region and identify those surrounded ... More
Chemical connections between low-mass stars and planets building blocks investigated by stellar population synthesisFeb 20 2019Connecting star and planet properties in a single model is not straightforward. Stellar population synthesis models are key to explore combined statistical constraints from stars and planets observations. The Besan\c{c}on stellar population synthesis ... More
Luminosity outburst chemistry in protoplanetary discs: going beyond standard tracersFeb 20 2019The chemical influence of luminosity outbursts on the environments of young solar-type stars is explored. Species are categorised into several types according to their response to the outburst. The first and second types imply chemical changes only during ... More
Jupiter's Ammonia Distribution Derived from VLA Maps at 3--37 GHzFeb 19 2019We observed Jupiter four times over a full rotation (10 hrs) with the upgraded Karl G. Jansky Very Large Array (VLA) between December 2013 and December 2014. Preliminary results at 4-17 GHz were presented in de Pater et al. (2016); in the present paper ... More
Planetesimal Population Synthesis: Pebble Flux Regulated Planetesimal FormationFeb 19 2019We propose an expression for a local planetesimal formation rate proportional to the instantaneous radial pebble flux. The result --- a radial planetesimal distribution --- can be used as initial condition to study the formation of planetary embryos. ... More
Contrasting turbulence in stably stratified flows and thermal convectionFeb 18 2019In this paper, the properties of stably stratified turbulence (SST) and turbulent thermal convection are contrasted. A key difference between these flows is the sign of the kinetic energy feed by buoyancy, $\mathcal{F}_B$. For SST, $\mathcal{F}_B < 0$ ... More
Rotational Desorption of Ice Mantles and Complex Molecules from Suprathermally Rotating Dust Grains around Young Stellar ObjectsFeb 18 2019Complex organic molecules (COMs) are increasingly observed in the environs of young stellar objects (YSOs), including hot cores/corinos around high-mass/low-mass protostars and protoplanetary disks. It is widely believed that COMs are first formed in ... More
An alternative interpretation of the exomoon candidate signal in the combined Kepler and Hubble data of Kepler-1625Feb 16 2019Kepler and Hubble photometry of a total of four transits by the Jupiter-sized Kepler-1625b have recently been interpreted to show evidence of a Neptune-sized exomoon. The profound implications of this first possible exomoon detection and the physical ... More
The SOPHIE search for northern extrasolar planets. XIV. A temperate ($T_\mathrm{eq}\sim 300$ K) super-earth around the nearby star Gliese 411Feb 15 2019Periodic radial velocity variations in the nearby M-dwarf star Gl411 are reported, based on measurements with the SOPHIE spectrograph. Current data do not allow us to distinguish between a 12.95-day period and its one-day alias at 1.08 days, but favour ... More
The SOPHIE search for northern extrasolar planets XV. A Warm Neptune around the M-dwarf Gl378Feb 15 2019We present the detection of a Warm Neptune orbiting the M-dwarf Gl378, using radial velocity measurements obtained with the SOPHIE spectrograph at the Observatoire de Haute-Provence. The star was observed in the context of the SOPHIE exoplanets consortium's ... More
Circular spectropolarimetric sensing of vegetation in the field; possibilities for the remote detection of extraterrestrial lifeFeb 15 2019Homochirality is a generic and unique property of all biochemical life and the fractional circular polarization it induces therefore constitutes an unambiguous biosignature. However, while high-quality circular polarimetric spectra can be easily and quickly ... More
Nitrogen-containing Anions and Tholin Growth in Titan's Ionosphere: Implications for Cassini CAPS-ELS ObservationsFeb 14 2019The Cassini Plasma Spectrometer (CAPS) Electron Spectrometer (ELS) instrument onboard Cassini revealed an unexpected abundance of negative ions above 950 km in Titan's ionosphere. \textit{In situ} measurements indicated the presence of negatively charged ... More
A Consistent Reduced Network for HCN Chemistry in Early Earth and Titan Atmospheres: Quantum Calculations of Reaction Rate CoefficientsFeb 14 2019HCN is a key ingredient for synthesizing biomolecules such as nucleobases and amino acids. We calculate 42 reaction rate coefficients directly involved with or in competition with the production of HCN in the early Earth or Titan atmospheres. These reactions ... More
Pebble accretion in self-gravitating protostellar discsFeb 14 2019Pebble accretion has become a popular component to core accretion models of planet formation, and is especially relevant to the formation of compact, resonant terrestrial planetary systems. Pebbles initially form in the inner protoplanetary disc, sweeping ... More
Aggregate Hazes in Exoplanet AtmospheresFeb 14 2019Photochemical hazes have been frequently used to interpret exoplanet transmission spectra that show an upward slope towards shorter wavelengths and weak molecular features. While previous studies have only considered spherical haze particles, photochemical ... More
Investigation of the asteroid-neutron star collision model for the repeating fast radio burstsFeb 14 2019The origin of fast radio bursts (FRBs) is still a mystery. One model proposed to interpret the only known repeating object, FRB 121102, is that the radio emission is generated from asteroids colliding with a highly magnetized neutron star (NS). With N-body ... More
Non-thermal emission from the interaction of magnetized exoplanets with the wind of their host starFeb 13 2019We study the non-thermal emission from the interaction between magnetized Jupiter-like exoplanets and the wind from their host star. The supersonic motion of planets through the wind forms a bow shock that accelerates electrons which produces non-thermal ... More
The Origin of Kepler-419b: A Path to Tidal Migration Via Four-body Secular InteractionsFeb 13 2019We test the high-eccentricity tidal migration scenario for Kepler-419b, a member of the eccentric warm Jupiter class of planets whose origin is debated. Kepler-419 hosts two known planets (b,c). However, in its current configuration, planet c cannot excite ... More
Dust unveils the formation of a mini-Neptune planet in a protoplanetary ringFeb 13 2019Rings and radial gaps are ubiquitous in protoplanetary disks. Their possible connection to planet formation is currently subject to intense debate. In principle, giant planet formation leads to wide gaps which separate the gas and dust mass reservoir ... More
Thermodynamics of Element Volatility and its Application to Planetary ProcessesFeb 13 2019Despite its importance in geological sciences, our understanding of interactions between gas and condensed phases (comprising solids and liquids) remains clouded by the fact that, often, only indirect evidence remains for their occurrence. This arises ... More
A reduced chemical scheme for modelling warm to hot hydrogen-dominated atmospheresFeb 13 2019Three dimensional models that account for chemistry are useful tools to predict the chemical composition of (exo)planet and brown dwarf atmospheres and interpret observations of future telescopes. Recent Juno observations of the NH3 tropospheric distribution ... More
Layered semi-convection and tides in giant planet interiors - II. Tidal dissipationFeb 13 2019Recent Juno observations have suggested that the heavy elements in Jupiter could be diluted throughout a large fraction of its gaseous envelope, providing a stabilising compositional gradient over an extended region of the planet. This could trigger layered ... More
A theoretical model for realistic local climatesFeb 13 2019We address the question of writing a model that ---considering the doubly-periodic forcing induced by solar radiation and the laws of irradiance and conduction--- reproduces realistic annual and daily modulations of temperatures on the surface of a small ... More
A limited habitable zone for complex lifeFeb 13 2019The habitable zone (HZ) is defined as the range of distances from a host star within which liquid water, a key requirement for life, may exist at a planet's surface. Substantially more CO2 than present in Earth's modern atmosphere is required to maintain ... More
The survivability of planetary systems in young and dense star clustersFeb 12 2019We perform a simulation using the Astrophysical Multipurpose Software Environment of the Orion Trapezium star cluster in which the evolution of the stars and the dynamics of planetary systems are taken into account. The initial conditions are selected ... More
Spatial segregation of dust grains in transition disks. SPHERE observations of 2MASS J16083070-3828268 and RXJ1852.3-3700Feb 12 2019Context. The mechanisms governing the opening of cavities in transition disks are not fully understood. Several processes have been proposed but their occurrence rate is still unknown. Aims. We present spatially resolved observations of two transition ... More
The consequences of planetary migration on the minor bodies of the early Solar SystemFeb 12 2019Pebble accretion is an efficient mechanism able to build up the core of the giant planets within the lifetime of the protoplanetary disc gas-phase. The core grows via this process until the protoplanet reaches its pebble isolation mass and starts to accrete ... More
The consequences of planetary migration on the minor bodies of the early Solar SystemFeb 12 2019Feb 20 2019Pebble accretion is an efficient mechanism able to build up the core of the giant planets within the lifetime of the protoplanetary disc gas-phase. The core grows via this process until the protoplanet reaches its pebble isolation mass and starts to accrete ... More
External photoevaporation of protoplanetary discs in Cygnus OB2: linking discs to star formation dynamical historyFeb 12 2019Feb 19 2019Many stars form in regions of enhanced stellar density, wherein the influence of stellar neighbours can have a strong influence on a protoplanetary disc (PPD) population. In particular, far ultraviolet (FUV) flux from massive stars drives thermal winds ... More
External photoevaporation of protoplanetary discs in Cygnus OB2: linking discs to star formation dynamical historyFeb 12 2019Many stars form in regions of enhanced stellar density, wherein the influence of stellar neighbours can have a strong influence on a protoplanetary disc (PPD) population. In particular, far ultraviolet (FUV) flux from massive stars drives thermal winds ... More
Observations of tides and circularization in red-giant binaries from Kepler photometryFeb 12 2019Binary stars are places of complex stellar interactions. While all binaries are in principle converging towards a state of circularization, many eccentric systems are found even in advanced stellar phases. In this work we discuss the sample of binaries ... More
Heavy metal rules. I. Exoplanet incidence and metallicityFeb 12 2019Discovery of only handful of exoplanets required to establish a correlation between giant planet occurrence and metallicity of their host stars. More than 20 years have already passed from that discovery, however, many questions are still under lively ... More
Interstellar ices: a possible scenario for symmetry breaking of extraterrestrial chiral organic molecules of prebiotic interestFeb 12 2019In the laboratory, the photo-and thermochemical evolution of ices, made of simple molecules of astrophysical relevance, always leads to the formation of semi-refractory water-soluble organic residues. Targeted searches for specific molecules do reveal ... More
Constraining Jupiter's internal flows using Juno magnetic and gravity measurementsFeb 12 2019Deciphering the flow below the cloud-level of Jupiter remains a critical milestone in understanding Jupiter's internal structure and dynamics. The expected high-precision Juno measurements of both the gravity field and the magnetic field might help to ... More
Saturn's deep atmospheric flows revealed by the Cassini Grand Finale gravity measurementsFeb 12 2019How deep do Saturn's zonal winds penetrate below the cloud-level has been a decades-long question, with important implications not only for the atmospheric dynamics, but also for the interior density structure, composition, magnetic field and core mass. ... More
Dusty outflows in planetary atmospheres: Understanding "super-puffs" and transmission spectra of sub-NeptunesFeb 11 2019`Super-puffs' are planets with anomalously low mean densities ($\lesssim 10^{-1}~{\rm g\ cm}^{-3}$). With a low surface gravity, the extended atmosphere is susceptible to extreme hydrodynamic mass loss (`boil off') on a timescale much shorter than the ... More
Could 1I/'Oumuamua be an icy fractal aggregate ejected from a protoplanetary disk? A fluffy radiation-pressure-driven scenarioFeb 11 20191I/'Oumuamua was the first interstellar interloper that has been detected and it showed a non-gravitational acceleration (Micheli et al. 2018) that cannot be accounted for by outgassing, given the strict upper limits to outgassing resulting from Spitzer ... More
Observing the gas component of circumplanetary disks around wide-orbit planet-mass companions in the (sub)mm regimeFeb 11 2019Several detections of wide-orbit planet-mass/sub-stellar companions around young solar-like stars were reported in the last decade. The origin of those possible planets is still unclear but accretion tracers and VLT/SPHERE observations indicate that they ... More
ISPY - the NaCo Imaging Survey for Planets around Young stars: A young companion candidate embedded in the R CrA cloudFeb 11 2019Within the NaCo-ISPY exoplanet imaging program, we aim at detecting and characterizing the population of low-mass companions at wide separations ($\gtrsim$10AU), focusing in particular on young stars either hosting a known protoplanetary disk or a debris ... More
Misaligned accretion disc formation via Kozai-Lidov oscillationsFeb 11 2019We investigate the formation and evolution of misaligned accretion discs around the secondary component of a binary through mass transfer driven by Kozai-Lidov oscillations of the circumprimary disc's eccentricity and inclination. We perform SPH simulations ... More
Stellar Activity Effects on Moist Habitable Terrestrial Atmospheres Around M dwarfsFeb 11 2019Transit spectroscopy of terrestrial planets around nearby M dwarfs is a primary goal of space missions in coming decades. 3-D climate modeling has shown that slow-synchronous rotating terrestrial planets may develop thick clouds at the substellar point, ... More
SPHERE: the exoplanet imager for the Very Large TelescopeFeb 11 2019Observations of circumstellar environments to look for the direct signal of exoplanets and the scattered light from disks has significant instrumental implications. In the past 15 years, major developments in adaptive optics, coronagraphy, optical manufacturing, ... More
Kuiper Belt-Like Hot and Cold Populations of Planetesimal Inclinations in the $β$ Pictoris Belt Revealed by ALMAFeb 11 2019The inclination distribution of the Kuiper belt provides unique constraints on its origin and dynamical evolution, motivating vertically resolved observations of extrasolar planetesimal belts. We present ALMA observations of millimeter emission in the ... More
Can a machine learn the outcome of planetary collisions?Feb 11 2019Planetary-scale collisions are common during the last stages of formation of solid planets, including the Solar system terrestrial planets. The problem of growing planets has been divided into studying the gravitational interaction of embryos relevant ... More
A water budget dichotomy of rocky protoplanets from $^{26}$Al-heatingFeb 11 2019In contrast to the water-poor inner solar system planets, stochasticity during planetary formation and order of magnitude deviations in exoplanet volatile contents suggest that rocky worlds engulfed in thick volatile ice layers are the dominant family ... More
Can we predict the impact conditions of meter-sized meteoroids?Feb 11 2019A few meter-sized meteoroids impact the atmosphere of the Earth per year. Most (if not all) of them are undetectable before the impact and hence, predicting where and how they will fall, seems to be impossible. In this letter we show compelling evidence ... More
A resonant pair of warm giant planets revealed by TESSFeb 11 2019We present the discovery of a pair of transiting giant planets, TOI-216b and c, using four sectors of TESS photometry. TOI-216 is a $0.87 M_{\odot}$ dwarf orbited by two transiters with radii of $8.2 R_{\oplus}$ and $11.3 R_{\oplus}$, and periods of $17.01$d ... More
CLIcK: a Continuum and Line fItting Kit for circumstellar disksFeb 11 2019Infrared spectroscopy with medium to high spectral resolution is essential to characterize the gas content of circumstellar disks. Unfortunately, conducting continuum and line radiative transfer of thermochemical disk models is too time-consuming to carry ... More
Tidal Heating and the Habitability of the TRAPPIST-1 ExoplanetsFeb 11 2019Context. New estimates of the masses and radii of the seven planets orbiting the ultracool M-dwarf TRAPPIST-1 star permit improved modelling of their compositions, heating by tidal dissipation, and removal of tidal heat by solid-state convection. Aims. ... More
Stellar energetic particles in the magnetically turbulent habitable zones of TRAPPIST-1-like planetary systemsFeb 11 2019Planets in close proximity to their parent star, such as those in the habitable zones around M dwarfs, could be subject to particularly high doses of particle radiation. We have carried out test-particle simulations of ~GeV protons to investigate the ... More
Should $N$-body integrators be symplectic everywhere in phase space?Feb 10 2019Symplectic integrators are the preferred method of solving conservative $N$-body problems in cosmological, stellar cluster, and planetary system simulations because of their superior error properties and ability to compute orbital stability. Newtonian ... More
Thermo-compositional diabatic convection in the atmospheres of brown dwarfs and in Earth's atmosphere and oceansFeb 10 2019By generalizing the theory of convection to any type of thermal and compositional source terms (diabatic processes), we show that thermohaline convection in Earth oceans, fingering convection in stellar atmospheres, and moist convection in Earth atmosphere ... More
Theoretical models of the outer disk of TW Hya presently forming in-situ planets and a comparison of all modeled ALMA disksFeb 09 2019We fit an isothermal oscillatory density model to the outer disk of TW Hya in which planets have presumably already formed and they are orbiting within four observed dark gaps. At first sight, this 52 AU small disk does not appear to be similar to our ... More
On the location of the ring around the dwarf planet HaumeaFeb 09 2019The recently discovered ring around the dwarf planet (136108) Haumea is located near the 1:3 resonance between the orbital motion of the ring particles and the spin of Haumea. In the current work is studied the dynamics of individual particles in the ... More
A New Generation of Cool White Dwarf Atmosphere Models. III. WD J2356$-$209: Accretion of a Planetesimal with an Unusual CompositionFeb 08 2019WD J2356$-$209 is a cool metal-polluted white dwarf whose visible spectrum is dominated by a strong and broad sodium feature. Although discovered nearly two decades ago, no detailed and realistic analysis of this star had yet been realized. In the absence ... More
First observation of a planetary transit with the SPARC4 CCD: improved parameters for HATS-24bFeb 08 2019The photometric monitoring of planetary transits is an important method for the characterization of exoplanets. Transiting exoplanets allow measurements of the planetary radius and mass, providing information on the physical structure of the planet. Therefore, ... More
A Single Physical Model for Diverse Meteoroid Data SetsFeb 08 2019The orbital distributions of dust particles in interplanetary space are inferred from several meteoroid data sets under the constraints imposed by the orbital evolution of the particles due to the planetary gravity and Poynting-Robertson effect. Infrared ... More
Speeding past planets? Asteroids radiatively propelled by giant branch Yarkovsky effectsFeb 07 2019Understanding the fate of planetary systems through white dwarfs which accrete debris crucially relies on tracing the orbital and physical properties of exo-asteroids during the giant branch phase of stellar evolution. Giant branch luminosities exceed ... More
K2-288Bb: A Small Temperate Planet in a Low-mass Binary System Discovered by Citizen ScientistsFeb 07 2019Observations from the Kepler and K2 missions have provided the astronomical community with unprecedented amounts of data to search for transiting exoplanets and other astrophysical phenomena. Here, we present K2-288, a low-mass binary system (M2.0 +/- ... More
Lunar impacts during eclipses separated by a Metonic cycle on Jan 21, 2000 and 2019: a possible origin from daytime Sagittarids/Capriconids meteor showerFeb 07 2019The lunar impact claimed by Zuluaga et al. (2019) during the total eclipse of 21 January has been discussed widely by his research group, introducing some results from the technique of gravitational ray-tracing. A similar event of magnitude 6 was observed ... More
Organic molecules in the protoplanetary disk of DG Tau revealed by ALMAFeb 07 2019Planets form in protoplanetary disks and inherit their chemical compositions. It is thus crucial to map the distribution and investigate the formation of simple organics, such as formaldehyde and methanol, in protoplanetary disks. We analyze ALMA observations ... More
Outgassing induced acceleration of comet 67P/Churyumov-GerasimenkoFeb 07 2019Cometary activity affects the orbital motion and rotation state due to sublimation induced forces. The availability of precise orientation and position data from the Rosetta missions allows one to accurately determine the outgassing of comet Churyumov-Gerasimenko/67P ... More
First detection of oscillations in the Halo giant HD 122563: validation of seismic scaling relations and new fundamental parametersFeb 07 2019The nearby metal-poor giant HD122563 is an important astrophysical laboratory for which to test stellar atmospheric and interior physics. It is also a benchmark star for which to calibrate methods to apply to large scale surveys. Recently it has been ... More
Dense Particle Clouds in Laboratory Experiments in Context of Drafting and Streaming InstabilityFeb 07 2019The streaming instability, as an example of instabilities driven by particle feedback on a gas flow, has been proven to have a major role in controlling the formation of planetesimals. Here, we present experiments to approach this situation in the laboratory ... More
Machine Vision and Deep Learning for Classification of Radio SETI SignalsFeb 06 2019We apply classical machine vision and machine deep learning methods to prototype signal classifiers for the search for extraterrestrial intelligence. Our novel approach uses two-dimensional spectrograms of measured and simulated radio signals bearing ... More
A variationally computed room temperature line list for AsH$_{3}$Feb 06 2019Calculations are reported on the rotation-vibration energy levels of the arsine molecule with associated transition intensities. A potential energy surface (PES) obtained from \textit{ab initio} electronic structure calculations is refined to experimental ... More
Ocean Dynamics and the Inner Edge of the Habitable Zone for Tidally Locked Terrestrial PlanetsFeb 06 2019Recent studies have shown that ocean dynamics can have a significant warming effect on the permanent night sides of 1 to 1 tidally locked terrestrial exoplanets with Earth-like atmospheres and oceans in the middle of the habitable zone. However, the impact ... More
Attitude Control of an Inflatable Sailplane for Mars ExplorationFeb 06 2019Feb 07 2019Exploration of Mars has been made possible using a series of landers, rovers and orbiters. The HiRise camera on the Mars Reconnaissance Orbiter (MRO) has captured high-resolution images covering large tracts of the surface. However, orbital images lack ... More
Attitude Control of an Inflatable Sailplane for Mars ExplorationFeb 06 2019Feb 15 2019Exploration of Mars has been made possible using a series of landers, rovers and orbiters. The HiRise camera on the Mars Reconnaissance Orbiter (MRO) has captured high-resolution images covering large tracts of the surface. However, orbital images lack ... More
Guidance, Navigation and Control of Asteroid Mobile Imager and Geologic Observer (AMIGO)Feb 06 2019The science and origins of asteroids is deemed high priority in the Planetary Science Decadal Survey. Major scientific goals for the study of planetesimals are to decipher geological processes in SSSBs not determinable from investigation via in-situ experimentation, ... More
Motion Planning on an Asteroid Surface with Irregular Gravity FieldsFeb 06 2019There are thousands of asteroids in near-Earth space and millions in the Main Belt. They are diverse in physical properties and composition and are time capsules of the early solar system. This makes them strategic locations for planetary science, resource ... More
The misaligned orbit of the Earth-sized planet Kepler-408bFeb 06 2019Feb 09 2019Kepler-408 is one of the 33 planet-hosting {\it Kepler} stars for which asteroseismology has been used to investigate the orientation of the stellar rotation axis relative to the planetary orbital plane. The transiting "hot Earth," Kepler-408b, has an ... More
The misaligned orbit of the Earth-sized planet Kepler-408bFeb 06 2019Kepler-408 is one of the 33 planet-hosting {\it Kepler} stars for which asteroseismology has been used to investigate the orientation of the stellar rotation axis relative to the planetary orbital plane. The transiting "hot Earth," Kepler-408b, has an ... More
Giant protostellar flares: accretion-driven accumulation and reconnection-driven ejection of magnetic flux in protostarsFeb 06 2019Protostellar flares are rapid magnetic energy release events associated with formation of hot plasma in protostars. In the previous models of protostellar flares, the interaction between a protostellar magnetosphere with the surrounding disk plays crucial ... More
Imaging the Distribution of Solids in Planet-forming Disks undergoing Hydrodynamical Instabilities with the Next Generation Very Large ArrayFeb 05 2019We present simulations of the capabilities of the Next Generation Very Large Array to image at high angular resolution substructures in the dust emission of protoplanetary disks. The main goal of this study is to investigate the kinds of substructures ... More
So close, so different: characterization of the K2-36 planetary system with HARPS-NFeb 05 2019K2-36 is a K dwarf orbited by two small ($R_{\rm b}=1.43\pm0.08$ $R_\oplus$ and $R_{\rm c}=3.2\pm0.3$ $R_\oplus$), close-in ($a_{\rm b}$=0.022 AU and $a_{\rm c}$=0.054 AU) transiting planets discovered by Kepler/K2. They are representatives of two families ... More
Exploring the formation by core accretion and the luminosity evolution of directly imaged planets: The case of HIP 65426 bFeb 05 2019Feb 20 2019A low-mass companion to the two-solar mass star HIP65426 has recently been detected by SPHERE at around 100 au from its host. Explaining the presence of super-Jovian planets at large separations, as revealed by direct imaging, is currently an open question. ... More
Exploring the formation by core accretion and the luminosity evolution of directly-imaged planets: The case of HIP 65426 bFeb 05 2019A low-mass companion to the two-solar mass star HIP65426 was recently detected by SPHERE at around 100 au from its host. Explaining the presence of super-jovian planets at large separations, as revealed by direct imaging, is currently an open question. ... More
Seasonal evolution of temperatures in Titan's lower stratosphereFeb 05 2019The Cassini mission offered us the opportunity to monitor the seasonal evolution of Titan's atmosphere from 2004 to 2017, i.e. half a Titan year. The lower part of the stratosphere (pressures greater than 10 mbar) is a region of particular interest as ... More
Debris of asteroid disruptions close to the SunFeb 05 2019The under-abundance of asteroids on orbits with small perihelion distances suggests that thermally-driven disruption may be an important process in the removal of rocky bodies in the Solar System. Here we report our study of how the debris streams arise ... More
Occurrence Rates of Planets orbiting FGK Stars: Combining Kepler DR25, Gaia DR2 and Bayesian InferenceFeb 04 2019We characterize the occurrence rate of planets, ranging in size from 0.5-16 R$_\oplus$, orbiting FGK stars with orbital periods from 0.5-500 days. Our analysis is based on results from the `DR25' catalog of planet candidates produced by NASA's Kepler ... More
Secular dynamics of binaries in stellar clusters II: dynamical evolutionFeb 04 2019Dense stellar clusters are natural sites for the origin and evolution of exotic objects such as relativistic binaries (potential gravitational wave sources), blue stragglers, etc. We investigate the secular dynamics of a binary system driven by the global ... More
Secular dynamics of binaries in stellar clusters II: dynamical evolutionFeb 04 2019Feb 18 2019Dense stellar clusters are natural sites for the origin and evolution of exotic objects such as relativistic binaries (potential gravitational wave sources), blue stragglers, etc. We investigate the secular dynamics of a binary system driven by the global ... More
A giant impact as the likely origin of different twins in the Kepler-107 exoplanet systemFeb 04 2019Measures of exoplanet bulk densities indicate that small exoplanets with radius less than 3 Earth radii ($R_\oplus$) range from low-density sub-Neptunes containing volatile elements to higher density rocky planets with Earth-like or iron-rich (Mercury-like) ... More
Closing the gap between Earth-based and interplanetary mission observations: Vesta seen by VLT/SPHEREFeb 04 2019Context. Over the past decades, several interplanetary missions have studied small bodies in situ, leading to major advances in our understanding of their geological and geophysical properties. These missions, however, have had a limited number of targets. ... More
Potential Vorticity of Saturn's Polar Regions: Seasonality and InstabilitiesFeb 04 2019We analyse the potential vorticity of Saturn's polar regions, as it is a fundamental dynamical tracer that enables us to improve our understanding of the dynamics of these regions and their seasonal variability. In particular, we present zonally averaged ... More
The Maribo CM2 meteorite fall - survival of weak material at high entry speedFeb 04 2019High entry speed (> 25 km/s) and low density (< 2500 kg/m3) are two factors that lower the chance of a meteoroid to drop meteorites. The 26 g carbonaceous (CM2) meteorite Maribo recovered in Denmark in 2009 was delivered by a superbolide observed by several ... More
Magnetic eddy viscosity of mean sheared flows in two-dimensional magnetohydrodynamicsFeb 04 2019Induction of magnetohydrodynamics (MHD) fluids at magnetic Reynolds number (Rm) less than~1 has long been known to cause magnetic drag. Here, we show that when $\Rm \gg 1$, and additionally in a hydrodynamic-dominated regime in which the magnetic energy ... More
Ultima Thule (486958; 2014 MU69): Necklace, Composition, Rotation, FormationFeb 04 2019Flyby images of Ultima Thule (486958; 2014 MU69) show a comparatively bright ``necklace'' between its two lobes, in contrast to its generally low albedo. The necklace is found in the most shaded, and therefore coolest, part of its surface. It may be clean, ... More
Temperatures of lunar impact flashes: mass and size distribution of small impactors hitting the MoonFeb 03 2019Lunar impact flashes have been monitored over the last 20 years for determining the mass frequency distribution of near-Earth objects in the cm-dm size range. In this work, using telescopic observations in R and I band from the NELIOTA database, impact ... More
Arecibo Radar Observations of Near-Earth Asteroid (3200) Phaethon During the 2017 ApparitionFeb 03 2019We report Arecibo S-band (2380 MHz; 12.6 cm) radar observations of near-Earth asteroid (3200) Phaethon during the December 2017 apparition when Phaethon passed within 0.07 au of Earth. Radar images with a resolution of 75 m per pixel reveal a roughly ... More
Surface tide on a rapidly rotating bodyFeb 03 2019By solving Laplace's tidal equations with friction terms we study the surface tide on a rapidly rotating body. When $\epsilon=\Omega^2 R/g$, the square of the ratio of dynamical timescale to rotational timescale, is very small for the Earth the asymptotic ... More
ALMA study of the HD 100453 AB system and the tidal interaction of the companion with the diskFeb 02 2019Context: The complex system HD 100453 AB with a ring-like circumprimary disk and two spiral arms, one of which is pointing to the secondary, is a good laboratory to test spiral formation theories. Aims: To quantify the interaction of HD 100453 B with ... More
Stellar Spectroscopy in the Near-infrared with a Laser Frequency CombFeb 01 2019The discovery and characterization of exoplanets around nearby stars is driven by profound scientific questions about the uniqueness of Earth and our Solar System, and the conditions under which life could exist elsewhere in our Galaxy. Doppler spectroscopy, ... More
On the 9:7 Mean Motion Resonance Capture in a System of Two Equal-mass Super-EarthsFeb 01 2019We study the formation of the 9:7 mean motion resonance in a system of two low-mass planets ($m_{1}=m_{2}=3M_{\oplus}$) embedded in a gaseous protoplanetary disk employing a full 2D hydrodynamic treatment of the disk-planet interactions. Our aim is to ... More