Latest in astro-ph.ep

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Spatially resolved spectroscopy of the debris disk HD 32297: Further evidence of small dust grainsAug 22 2019Spectro-photometry of debris disks in total intensity and polarimetry can provide new insight into the properties of the dust grains therein (size distribution and optical properties). We aim to constrain the morphology of the highly inclined debris disk ... More
Planetary-scale variations in winds and UV brightness at the Venusian cloud top: Periodicity and temporal evolutionAug 22 2019Planetary-scale waves at the Venusian cloud-top cause periodic variations in both winds and ultraviolet (UV) brightness. While the wave candidates are the 4-day Kelvin wave and 5-day Rossby wave with zonal wavenumber 1, their temporal evolutions are poorly ... More
Interpretation of shadows and antishadows on Saturn and the evidence against south polar eyewallsAug 21 2019Cassini spacecraft observations of Saturn in 2006 revealed south polar cloud shadows, the common interpretation of which was initiated by Dyudina et al. (2008, Science 319, 1801) who suggested they were being cast by concentric cloud walls, analogous ... More
Saturn's south polar cloud composition and structure inferred from 2006 Cassini/VIMS spectra and ISS imagesAug 21 2019We used 0.85 - 5.1 micron 2006 observations by Cassini's Visual and Infrared Mapping Spectrometer (VIMS) to constrain the unusual vertical structure and compositions of cloud layers in Saturn's south polar region, the site of a powerful vortex circulation, ... More
Tidal circularization of gaseous planets orbiting white dwarfsAug 21 2019A gas giant planet which survives the giant branch stages of evolution at a distance of many au and then is subsequently perturbed sufficiently close to a white dwarf will experience orbital shrinkage and circularization due to star-planet tides. The ... More
Interpretation and diversity of exoplanetary material orbiting white dwarfsAug 21 2019Nine metal-polluted white dwarfs are observed with medium-resolution optical spectroscopy,where photospheric abundances are determined and interpreted through comparison against solar system objects. An improved method of making such comparisons is presented ... More
Modeling Time Dependent Water Chemistry Due to Powerful X-ray Flares from T-Tauri StarsAug 21 2019Young stars emit strong flares of X-ray radiation that penetrate the surface layers of their associated protoplanetary disks. It is still an open question as to whether flares create significant changes in disk chemical composition. We present models ... More
The Physical Origin of the Venus Low Atmosphere Chemical GradientAug 21 2019Venus shares many similarities with the Earth, but concomitantly, some of its features are extremely original. This is especially true for its atmosphere, where high pressures and temperatures are found at the ground level. In these conditions, carbon ... More
Planetary systems in a star cluster I: the Solar system scenarioAug 21 2019Young stars are mostly found in dense stellar environments, and even our own Solar system may have formed in a star cluster. Here, we numerically explore the evolution of planetary systems similar to our own Solar system in star clusters. We investigate ... More
GAUSS -- A Sample Return Mission to CeresAug 21 2019The goal of Project GAUSS is to return samples from the dwarf planet Ceres. Ceres is the most accessible ocean world candidate and the largest reservoir of water in the inner solar system. It shows active cryovolcanism and hydrothermal activities in recent ... More
Precise Radial Velocities of Cool Low Mass Stars With iSHELLAug 20 2019The coolest dwarf stars are intrinsically faint at visible wavelengths and exhibit rotationally modulated stellar activity from spots and plages. It is advantageous to observe these stars at near infrared (NIR) wavelengths (1-2.5 microns) where they emit ... More
Graze-and-Merge Collisions under External PerturbersAug 20 2019Graze-and-merge collisions (GMCs) are common multi-step mergers occurring in low-velocity off-axis impacts between similar sized planetary bodies. The first impact happens at somewhat faster than the mutual escape velocity; for typical impact angles this ... More
Towards precise stellar ages: combining isochrone fitting with empirical gyrochronologyAug 20 2019We present a new age-dating technique that combines gyrochronology with isochrone fitting to infer ages for FGKM main-sequence and subgiant field stars. Gyrochronology and isochrone fitting are each capable of providing relatively precise ages for field ... More
New Spatially Resolved Imaging of the SR 21 Transition Disk and Constraints on the Small-Grain Disk GeometryAug 20 2019We present new 0.6 - 4 $\mu$m imaging of the SR 21 transition disk from Keck/NIRC2 and Magellan/MagAO. The protoplanetary disk around SR 21 has a large (~ 30 - 40 AU) clearing first inferred from its spectral energy distribution and later detected in ... More
Detection of Propadiene on TitanAug 20 2019The atmosphere of Titan, the largest moon of Saturn, is rich in organic molecules, and it has been suggested that the moon may serve as an analog for the pre-biotic Earth due to its highly reducing chemistry and existence of global hazes. Photochemical ... More
Herschel map of Saturn's stratospheric water, delivered by the plumes of EnceladusAug 20 2019Context. The origin of water in the stratospheres of Giant Planets has been an outstanding question ever since its first detection by ISO some 20 years ago. Water can originate from interplanetary dust particles, icy rings and satellites and large comet ... More
Constraining the detectability of water ice in debris disksAug 20 2019Water ice is important for the evolution and preservation of life. Identifying the distribution of water ice in debris disks is therefore of great interest in the field of astrobiology. Furthermore, icy dust grains are expected to play important roles ... More
The gravity field and interior structure of DioneAug 20 2019During its mission in the Saturn system, Cassini performed five close flybys of Dione. During three of them, radio tracking data were collected during the closest approach, allowing estimation of the full degree-2 gravity field by precise spacecraft orbit ... More
The Dust Particle Radial Distribution in the HL Tau Disk from ALMA and VLA ObservationsAug 20 2019Understanding planet formation requires to discern how dust grows in protoplanetary disks. An important parameter to measure in disks is the maximum dust grain size present. This is usually estimated through measurements of the dust opacity at different ... More
First sub-arcsecond submillimeter-wave [C I] image of 49 Ceti with ALMAAug 19 2019We present the first sub-arcsecond images of 49 Ceti in the [C I]3P1-3P0 emission and the 614 micron dust continuum emission observed with ALMA, as well as that in the CO(J=3-2) emission prepared by using the ALMA archival data. The spatial distribution ... More
Hot Jupiters are Destroyed by Tides While Their Host Stars are on the Main SequenceAug 19 2019While cooler giant planets are often observed with non-zero eccentricities, the short-period circular orbits of hot Jupiters suggest that they lose orbital energy and angular momentum due to tidal interactions with their host stars. However, orbital decay ... More
WISE J072003.20-084651.2B Is A Massive T DwarfAug 19 2019We present individual dynamical masses for the nearby M9.5+T5.5 binary WISE J072003.20$-$084651.2AB, a.k.a. Scholz's star. Combining high-precision CFHT/WIRCam photocenter astrometry and Keck adaptive optics resolved imaging, we measure the first high-quality ... More
How Flow Isolation May Set the Mass Scale for Super-Earth PlanetsAug 19 2019Much recent work on planet formation has focused on the growth of planets by accretion of grains whose aerodynamic properties make them marginally coupled to the nebular gas, a theory commonly referred to as "pebble accretion". While pebble accretion ... More
Super-Earth ingestion can explain the anomalously high metal abundances of M67 Y2235Aug 19 2019We investigate the hypothesis that ingestion of a terrestrial or super-Earth planet could cause the anomalously high metal abundances seen in a turn-off star in the open cluster M67, when compared to other turn-off stars in the same cluster. We show that ... More
Probing the Survival of Planetary Systems in Globular Clusters with Tidal Disruption EventsAug 19 2019Among the growing list of confirmed exoplanets, the number of planets identified in dense star clusters remains sparse. Previous analyses have suggested this may be due in part to dynamical interactions that unbind large fractions of planets from their ... More
Probing the Survival of Planetary Systems in Globular Clusters with Tidal Disruption EventsAug 19 2019Aug 22 2019Among the growing list of confirmed exoplanets, the number of planets identified in dense star clusters remains sparse. Previous analyses have suggested this may be due in part to dynamical interactions that unbind large fractions of planets from their ... More
Absence of a thick atmosphere on the terrestrial exoplanet LHS 3844bAug 19 2019Most known terrestrial planets orbit small stars with radii less than 60% that of the Sun. Theoretical models predict that these planets are more vulnerable to atmospheric loss than their counterparts orbiting Sun-like stars. To determine whether a thick ... More
An independent analysis of the Spitzer/IRAC phase curves of WASP43 bAug 19 2019We present here a reanalysis of the Spitzer Space Telescope phase curves of the hot Jupiter WASP43 b, using the wavelet pixel-Independent Component Analysis, a blind signal-source separation method. The data analyzed were recorded with the InfraRed Array ... More
Erosion of an exoplanetary atmosphere caused by stellar windsAug 19 2019We present a formalism for a first-order estimation of the magnetosphere radius of exoplanets orbiting stars in the range from 0.08 to 1.3 Mo. With this radius, we estimate the atmospheric surface that is not protected from stellar winds. We have analyzed ... More
The trans-Neptunian object (84922) 2003 VS2 through stellar occultationsAug 19 2019We present results from three world-wide campaigns that resulted in the detections of two single-chord and one multi-chord stellar occultations by the Plutino object (84922) 2003~VS$_2$. From the single-chord occultations in 2013 and 2014 we obtained ... More
The Traditional Approximation of Rotation including the centrifugal acceleration for slightly deformed starsAug 18 2019The Traditional Approximation of Rotation (TAR) is a treatment of the dynamical equations of rotating stably stratified fluids where the action of the Coriolis acceleration along the direction of the entropy (and chemicals) stratification is neglected ... More
Mini-magnetospheres and Moon-magnetosphere interactions: Overview Moon-magnetosphere InteractionsAug 18 2019"Moon-magnetosphere interaction" stands for the interaction of magnetospheric plasma with an orbiting moon. Observations and modeling of moon-magnetosphere interaction is a highly interesting area of space physics because it helps to better understand ... More
Orbital dynamics of circumbinary planetsAug 17 2019We investigate the dynamics of a nonzero mass, circular orbit planet around an eccentric orbit binary for various values of the binary eccentricity, binary mass fraction, planet mass, and planet semi--major axis by means of numerical simulations. Previous ... More
Impact of planetary mass uncertainties on exoplanet atmospheric retrievalsAug 17 2019In current models used to interpret exoplanet atmospheric observations, the planetary mass is treated as a prior and is estimated independently with external methods (e.g: radial velocity or Transit Timing Variation techniques). This approach is necessary ... More
Homogeneous Analysis of Hot Earths: Masses, Sizes, and CompositionsAug 17 2019Terrestrial planets have been found orbiting Sun-like stars with extremely short periods --- some as short as 4 hours. These ``ultra-short-period planets'' or ''hot Earths'' are so strongly irradiated that any initial H/He atmosphere has probably been ... More
Interaction of Stars Hosting Planets with Sgr A* Black holeAug 17 2019We present some preliminary results of our ongoing project about planetary systems around S-stars in the vicinity of Sgr A* black hole. Since S-stars might have migrated in the Galactic Centre (GC) from elsewhere, they probably still keep their planetary ... More
The impact of stripped cores on the frequency of Earth-size planets in the habitable zoneAug 16 2019The frequency of Earth-size planets in the habitable zone of Sun-like stars, hereafter $\eta_\oplus$, is a key parameter to evaluate the yield of nearby Earth analogues that can be detected and characterized by future missions. Yet, this value is poorly ... More
Kuiperian Objects and Wandering Cosmic ObjectsAug 16 2019We study the effects of an encounter between a wandering cosmic object (WCO) of 0.1 solar mass and some Kuiperian Objects (KO). First, we let the WCO cross the out-skirt of ou Kuiper belt. Such encounters can produce two types of solar objects: Eccentric ... More
Driving white dwarf metal pollution through unstable eccentric periodic orbitsAug 16 2019Planetary debris is observed in the atmospheres of over 1,000 white dwarfs, and two white dwarfs are now observed to contain orbiting minor planets. Exoasteroids and planetary core fragments achieve orbits close to the white dwarf through scattering with ... More
The Search for Living Worlds and the Connection to Our Cosmic OriginsAug 16 2019One of the most exciting scientific challenges is to detect Earth-like planets in the habitable zones of other stars in the galaxy and search for evidence of life. The ability to observe and characterise dozens of potentially Earth-like planets now lies ... More
Habitability of galaxies and application of merger trees in astrobiologyAug 16 2019Galaxies represent the main form of organization of matter in our universe. Therefore, they are of obvious interest for the new multidisciplinary field of astrobiology. In particular, to study habitability of galaxies represents one of the main emerging ... More
Inner Edge of Habitable Zones for Earth-sized Planets with Various Surface Water DistributionsAug 16 2019When planets receive insolation above a certain critical value called the runaway threshold, liquid surface water vaporizes completely, which forms the inner edge of the habitable zone. Because land planets can emit a large amount of radiation from the ... More
The Kepler Peas in a Pod Pattern is AstrophysicalAug 16 2019Recent work has found that in the NASA Kepler multi-planet systems, the planets tend to have similar sizes to their neighbors and regular orbital spacing (Weiss et al. 2018, Millholland et al. 2017), and also the outer planet of a pair tends to be larger ... More
Metallic liquid H3O in a thin-shell zone inside Uranus and NeptuneAug 16 2019The Solar System harbors deep unresolved mysteries despite centuries-long study. A highly intriguing case concerns anomalous non-dipolar and non-axisymmetric magnetic fields of Uranus and Neptune that have long eluded explanation by the prevailing theory. ... More
Dusty clumps in circumbinary discsAug 15 2019Aug 20 2019Recent observations have revealed that protoplanetary discs often exhibit cavities and azimuthal asymmetries such as dust traps and clumps. The presence of a stellar binary system in the inner disc regions has been proposed to explain the formation of ... More
Dusty clumps in circumbinary discsAug 15 2019Recent observations have revealed that protoplanetary discs often exhibit cavities and azimuthal asymmetries such as dust traps and clumps. The presence of a stellar binary system in the inner disc regions has been proposed to explain the formation of ... More
Simulations of starspot anomalies within TESS exoplanetary transit light curves -- I. The detection limits of starspot anomalies in TESS light curvesAug 15 201920573 simulations of planetary transits around spotted stars were conducted using the transit-starspot model, \texttt{PRISM}. In total 3888 different scenarios were considered using three different host star spectral types, M4V, M1V and K5V. The mean ... More
Excitation of Tumbling in Phobos and DeimosAug 15 2019Mass-spring model simulations are used to investigate past spin states of Phobos and Deimos. From an initially tidally locked state, we find crossing of a spin-orbit resonance with Mars or a mean motion resonance with each other does not excite tumbling ... More
REBOUNDx: A Library for Adding Conservative and Dissipative Forces to Otherwise Symplectic N-body IntegrationsAug 15 2019Symplectic methods, in particular the Wisdom-Holman map, have revolutionized our ability to model the long-term, conservative dynamics of planetary systems. However, many astrophysically important effects are dissipative. The consequences of incorporating ... More
Properties of the Interstellar Medium along Sight Lines to Nearby Planet Hosting StarsAug 15 2019We analyze high-resolution ultraviolet spectra of three nearby exoplanet host stars (HD 192310, HD 9826, and HD 206860) to study interstellar properties along their lines of sight and to search for the presence of astrospheric absorption. Using HST/STIS ... More
First resolved observations of a highly asymmetric debris disc around HD 160305 with VLT/SPHEREAug 14 2019Context. Direct imaging of debris discs gives important information about their nature, their global morphology, and allows us to identify specific structures possibly in connection with the presence of gravitational perturbers. It is the most straightforward ... More
Chaos in the inert Oort cloudAug 14 2019Context: Distant trans-Neptunian objects are subject to planetary perturbations and galactic tides. The former decrease with the distance, while the latter increase. In the intermediate regime where they have the same order of magnitude (the 'inert Oort ... More
Linking the Solar System and Extrasolar Planetary Systems with Radar Astronomy: Infrastructure for "Ground Truth" ComparisonAug 14 2019Planetary radars have obtained unique science measurements about solar system bodies and they have provided orbit determinations allowing spacecraft to be navigated throughout the solar system. Notable results have been on Venus, Earth's "twin," and small ... More
Abundant refractory sulfur in protoplanetary disksAug 14 2019Aug 15 2019Sulfur is one of the most abundant elements in the Universe, with important roles in astro-, geo-, and biochemistry. Its main reservoirs in planet-forming disks have previously eluded detection: gaseous molecules only account for $<1\,$\% of total elemental ... More
Abundant refractory sulfur in protoplanetary disksAug 14 2019Sulfur is one of the most abundant elements in the Universe, with important roles in astro-, geo-, and biochemistry. Its main reservoirs in planet-forming disks have previously eluded detection: gaseous molecules only account for $<1\,$\% of total elemental ... More
The First Detection of 13C17O in a Protoplanetary Disk: a Robust Tracer of Disk Gas MassAug 14 2019Measurements of the gas mass are necessary to determine the planet formation potential of protoplanetary disks. Observations of rare CO isotopologues are typically used to determine disk gas masses; however, if the line emission is optically thick this ... More
Constraining the Formation of the Four Terrestrial Planets in the Solar SystemAug 14 2019To reproduce the orbits and masses of the terrestrial planets (analogs) of the solar system, most studies scrutinize simulations for success as a batch. However, there is insufficient discussion in the literature on the likelihood of forming planet analogs ... More
Measuring the Orbital Parameters of Radial Velocity Systems in Mean Motion Resonance---a Case Study of HD 200964Aug 13 2019The presence of mean motion resonances (MMRs) complicates analysis and fitting of planetary systems observed through the radial velocity (RV) technique. MMR can allow planets to remain stable in regions of phase space where strong planet-planet interactions ... More
Red Dots: A temperate 1.5 Earth-mass planet in a compact multi-terrestrial planet system around GJ1061Aug 13 2019Small low-mass stars are favourable targets for the detection of rocky habitable planets. In particular, planetary systems in the solar neighbourhood are interesting and suitable for precise characterisation. The Red Dots campaigns seek to discover rocky ... More
Catalog for the ESPRESSO blind radial velocity exoplanet surveyAug 13 2019One of the main scientific drivers for ESPRESSO,\'Echelle SPectrograph, is the detection and characterization of Earth-class exoplanets. With this goal in mind, the ESPRESSO Guaranteed Time Observations (GTO) Catalog identifies the best target stars for ... More
Catalog for the ESPRESSO blind radial velocity exoplanet surveyAug 13 2019Aug 16 2019One of the main scientific drivers for ESPRESSO,\'Echelle SPectrograph, is the detection and characterization of Earth-class exoplanets. With this goal in mind, the ESPRESSO Guaranteed Time Observations (GTO) Catalog identifies the best target stars for ... More
Chaotic rotation and evolution of asteroids and small planets in high-eccentricity orbits around white dwarfsAug 13 2019Observed planetary debris in white dwarf atmospheres predominately originate from the destruction of small bodies on highly eccentric ($>0.99$) orbits. Despite their importance, these minor planets have coupled physical and orbital evolution which has ... More
The Beam Balance -- Measuring Binary Systems via Relativistic Beaming Signals from Stars and their CompanionsAug 13 2019In this paper I show that the concept of relativistic beaming -- the process by which light emitted by a fast moving sources is lensed towards the direction of motion -- can be easily extended to model the signal from both the star and any secondary companions. ... More
Lack of close-in, massive planets of main-sequence A-type stars from KeplerAug 13 2019Some theories of planet formation and evolution predict that intermediate-mass stars host more hot Jupiters than Sun-like stars, others reach the conclusion that such objects are very rare. By determining the frequencies of those planets we can test those ... More
Homogeneously derived transit timings for 17 exoplanets and reassessed TTV trends for WASP-12 and WASP-4Aug 13 2019We homogeneously analyse $\sim 3.2\times 10^5$ photometric measurements for $\sim 1100$ transit lightcurves belonging to $17$ exoplanet hosts. The photometric data cover $16$ years 2004--2019 and include amateur and professional observations. Old archival ... More
Earth as an Exoplanet: A Two-dimensional Alien MapAug 12 2019Resolving spatially-varying exoplanet features from single-point light curves is essential for determining whether Earth-like worlds harbor geological features and/or climate systems that influence habitability. To evaluate the feasibility and requirements ... More
In-Situ Scattering of Warm Jupiters and Implications for Dynamical HistoriesAug 12 2019Many warm Jupiters (WJs) have substantial eccentricities, which are linked to their formation and migration histories. This paper explores eccentricity excitation of WJs due to planet-planet scattering, beginning with 3-4 planets in unstable orbits, with ... More
29P/Schwassmann-Wachmann 1, A Centaur in the Gateway to the Jupiter-Family CometsAug 12 2019Jupiter Family Comets (JFCs) are the evolutionary products of trans-Neptunian objects (TNOs) that evolve through the giant planet region as Centaurs and into the inner solar system. Through numerical orbital evolution calculations following a large number ... More
Pebbles versus Planetesimals: The case of Trappist-1Aug 12 2019We present a study on the formation of planetary systems around low mass stars similar to Trappist-1, through the accretion of either planetesimals or pebbles. The aim is to determine if the currently observed systems around low mass stars favour one ... More
Biofluorescent Worlds I: Global Biological Fluorescence as a BiosignatureAug 12 2019In this paper, we analyze a new possible biological surface feature for habitable worlds orbiting other stars: biofluorescence. High ultraviolet (UV) and blue radiation fluxes drive the strongest biofluorescence in terrestrial fluorescent pigments and ... More
Cometary Chemistry and the Origin of Icy Solar System Bodies, the view after RosettaAug 12 2019In situ research on cometary chemistry began when measurements from the Giotto mission at comet 1P/Halley revealed the presence of complex organics in the coma. New telescopes and space missions have provided detailed remote and in situ measurements of ... More
High-resolution Infrared Spectrograph for Exoplanet Characterization with the Keck and Thirty Meter TelescopesAug 09 2019HISPEC (High-resolution Infrared Spectrograph for Exoplanet Characterization) is a proposed diffraction-limited spectrograph for the W.M. Keck Observatory, and a pathfinder for the MODHIS facility project (Multi-Object Diffraction-limited High-resolution ... More
New Astronomy Reviews Special Issue: History of Kepler's Major Exoplanet "Firsts"Aug 09 2019NASA's Kepler Mission revolutionized exoplanet science in the early part of the 2010's. Looking back from the perspective of the end of that decade, Kepler appears to have burst upon the scene ready for battle, like Athena springing forth, fully formed, ... More
Design Considerations for a Ground-Based Search for Transiting Planets around L and T DwarfsAug 09 2019Aug 21 2019We present design considerations for a ground-based survey for transiting exoplanets around L and T dwarfs, spectral classes that have yet to be thoroughly probed for planets. We simulate photometry for L and T targets with a variety of red-optical and ... More
Design Considerations for a Ground-Based Search for Transiting Planets around L and T DwarfsAug 09 2019We present design considerations for a ground-based survey for transiting exoplanets around L and T dwarfs, spectral classes that have yet to be thoroughly probed for planets. We simulate photometry for L and T targets with a variety of red-optical and ... More
The Evolution of Earth's Magnetosphere During the Solar Main SequenceAug 09 2019As a star spins-down during the main sequence, its wind properties are affected. In this work, we investigate how the Earth's magnetosphere has responded to the change in the solar wind. Earth's magnetosphere is simulated using 3D magnetohydrodynamic ... More
Evolution of atmospheric escape in close-in giant planets and their associated Ly$α$ and H$α$ transit predictionsAug 09 2019Strong atmospheric escape has been detected in several close-in exoplanets. As these planets are mostly made of hydrogen, observations in hydrogen lines, such as Ly-alpha and H-alpha lines, are powerful diagnostics of escape. Here, we simulate the evolution ... More
On the accuracy of symplectic integrators for secularly evolving planetary systemsAug 09 2019Symplectic integrators have made it possible to study the long-term evolution of planetary systems with direct N-body simulations. In this paper we reassess the accuracy of such simulations by running a convergence test on 20Myr integrations of the Solar ... More
A Great Successor to the Hubble Space TelescopeAug 08 2019Aug 14 2019The Hubble Space Telescope (HST) has been the most impactful science-driven mission ever flown by NASA. However, when HST reaches the end of its life, there will be a void due to the loss of some of the science capabilities afforded by HST to astronomers ... More
A Great Successor to the Hubble Space TelescopeAug 08 2019The Hubble Space Telescope (HST) has been the most impactful science-driven mission ever flown by NASA. However, when HST reaches the end of its life, there will be a void due to the loss of some of the science capabilities afforded by HST to astronomers ... More
Systematic Variations of CO Gas Abundance with Radius in Gas-rich Protoplanetary DisksAug 08 2019CO is the most widely used gas tracer of protoplanetary disks. Its abundance is usually assumed to be an interstellar ratio throughout the warm molecular layer of the disk. But recent observations of low CO gas abundance in many protoplanetary disks challenge ... More
Impacts into rotating targets: angular momentum draining and efficient formation of synthetic familiesAug 08 2019About 10% of the observed asteroids have rotational periods lower than P = 3 h and they seem to be relatively close to the spin barrier. Yet, the rotation has often been neglected in simulations of asteroid collisions. To determine the effect of rotation, ... More
Analytic Planetary Transit Light Curves and Derivatives for Stars with Polynomial Limb DarkeningAug 08 2019We derive analytic, closed-form solutions for the light curve of a planet transiting a star with a limb darkening profile which is a polynomial function of the stellar elevation, up to arbitrary integer order. We provide improved analytic expressions ... More
Science opportunities enabled by the era of Visible Band Stellar Imaging with sub-100 μarc-sec angular resolutionAug 08 2019This white paper briefly summarizes stellar science opportunities enabled by ultra-high resolution (sub-100 {\mu} arc-sec) astronomical imaging in the visible (U/V) wavebands. Next generation arrays of Imaging Cherenkov telescopes, to be constructed in ... More
Photophoresis in the circumjovian disk and its impact on the orbital configuration of the Galilean satellitesAug 08 2019Jupiter has four large regular satellites called the Galilean satellites: Io, Europa, Ganymede, and Callisto. The inner three of the Galilean satellites orbit in a 4:2:1 mean motion resonance; therefore their orbital configuration may originate from the ... More
Geometrical structure and thermal conductivity of dust aggregates formed via ballistic cluster-cluster aggregationAug 08 2019We herein report a theoretical study of the geometrical structure of porous dust aggregates formed via ballistic cluster-cluster aggregation (BCCA). We calculated the gyration radius $R_{\rm gyr}$ and the graph-based geodesic radius $R_{\rm geo}$ as a ... More
Impact probability computation of Near-Earth Objects using Monte Carlo Line Sampling and Subset SimulationAug 08 2019This work introduces two Monte Carlo (MC)-based sampling methods, known as line sampling and subset simulation, to improve the performance of standard MC analyses in the context of asteroid impact risk assessment. Both techniques sample the initial uncertainty ... More
Volatile species in comet 67P/Churyumov-Gerasimenko -- investigating the link from the ISM to the terrestrial planetsAug 08 2019Comets contain abundant amounts of organic and inorganic species. Many of the volatile molecules in comets have also been observed in the interstellar medium and some of them even with similar relative abundances, indicating formation under similar conditions ... More
Venus as a Laboratory for Exoplanetary ScienceAug 07 2019The current goals of the astrobiology community are focused on developing a framework for the detection of biosignatures, or evidence thereof, on objects inside and outside of our solar system. A fundamental aspect of understanding the limits of habitable ... More
Sulfate Aerosol Hazes and SO2 Gas as Constraints on Rocky Exoplanets' Surface Liquid WaterAug 07 2019Despite surface liquid water's importance to habitability, observationally diagnosing its presence or absence on exoplanets is still an open problem. Inspired within the Solar System by the differing sulfur cycles on Venus and Earth, we investigate thick ... More
How planets grow by pebble accretion II: Analytical calculations on the evolution of polluted envelopesAug 07 2019Context: Proto-planets acquire hot envelopes as they form. This ensures that the solids they accrete - pebbles as well as small planetesimals - will vaporize to enrich their atmospheres. Aims: To describe the complete evolution of planets with polluted ... More
WFIRST and EUCLID: enabling the microlensing parallax measurement from spaceAug 07 2019The Wide Field Infrared Survey Telescope (WFIRST) is expected to detect hundreds of free-floating planets, but it will not be able to measure their masses. However, simultaneous microlensing observations by both Euclid and WFIRST spacecraft, separated ... More
Comet C/2018 V1 (Machholz-Fujikawa-Iwamoto): dislodged from the Oort Cloud or coming from interstellar space?Aug 07 2019The chance discovery of the first interstellar minor body, 1I/2017 U1 (`Oumuamua), indicates that we may have been visited by such objects in the past and that these events may repeat in the future. Unfortunately, minor bodies following nearly parabolic ... More
Scaling Relations for Terrestrial Exoplanet Atmospheres from Baroclinic CriticalityAug 07 2019The macroturbulent atmospheric circulation of Earth-like planets mediates their equator-to-pole heat transport. For fast-rotating terrestrial planets, baroclinic instabilities in the mid-latitudes lead to turbulent eddies that act to transport heat poleward. ... More
Climate simulations of early Mars with estimated precipitation, runoff, and erosion ratesAug 07 2019The debate over the early Martian climate is among the most intriguing in planetary science. Although the geologic evidence generally supports a warmer and wetter climate, climate models have had difficulty simulating such a scenario, leading some to ... More
Climate simulations of early Mars with estimated precipitation, runoff, and erosion ratesAug 07 2019Aug 11 2019The debate over the early Martian climate is among the most intriguing in planetary science. Although the geologic evidence generally supports a warmer and wetter climate, climate models have had difficulty simulating such a scenario, leading some to ... More
Venus: Key to understanding the evolution of terrestrial planetsAug 07 2019As we become aware of Earth's changing climate, and as we discover terrestrial planets in other solar systems, we gain ever more reasons to study the Earth's nearest neighbour and closest sibling, the only Earth-sized planet besides our own that can be ... More
Estimating dayside effective temperatures of hot Jupiters and associated uncertainties through Gaussian process regressionAug 07 2019In this work, we outline a new method for estimating dayside effective temperatures of exoplanets and associated uncertainties using Gaussian process (GP) regression. By applying our method to simulated observations, we show that the GP method estimates ... More
Linking planetesimal and dust content in protoplanetary disks via a local toy modelAug 07 2019If planetesimal formation is an efficient process, as suggested by several models involving gravitational collapse of pebble clouds, then, before long, a significant part of the primordial dust mass should be absorbed in many km sized objects. A good ... More
Phase-Apodized-Pupil Lyot Coronagraphs for Arbitrary Telescope PupilsAug 07 2019The phase-apodized-pupil Lyot coronagraph (PAPLC) is a pairing of the apodized-pupil Lyot coronagraph (APLC) and the apodizing phase plate (APP) coronagraph. We describe a numerical optimization method to obtain globally-optimal solutions for the phase ... More