Latest in astro-ph.ep

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The Cosmic Dust Analyzer onboard Cassini: ten years of discoveriesFeb 13 2018The interplanetary space probe Cassini/Huygens reached Saturn in July 2004 after seven years of cruise phase. The Cosmic Dust Analyzer (CDA) measures the interplanetary, interstellar and planetary dust in our solar system since 1999 and provided unique ... More
The consequences of a nearby supernova on the early Solar SystemFeb 12 2018If the Sun was born in a relatively compact open cluster (half-mass radius ~3pc) with ~10^3 stars, it is quite likely that a massive (>10MSun) star was nearby when it exploded in a supernova. The repercussions of a supernova can be rather profound, and ... More
Tidal evolution of the Moon from a high-obliquity, high-angular-momentum EarthFeb 09 2018In the giant impact hypothesis for lunar origin, the Moon accreted from an equatorial circum-terrestrial disk; however the current lunar orbital inclination of 5 degrees requires a subsequent dynamical process that is still debated. In addition, the giant ... More
The ALMA-PILS survey: The sulphur connection between protostars and comets: IRAS 16293-2422 B and 67P/Churyumov-GerasimenkoFeb 08 2018The evolutionary past of our Solar System can be pieced together by comparing analogous low-mass protostars with remnants of our Protosolar Nebula - comets. Sulphur-bearing molecules may be unique tracers of the joint evolution of the volatile and refractory ... More
The chemical connection between 67P/C-G and IRAS 16293-2422Feb 08 2018The chemical evolution of a star- and planet-forming system begins in the prestellar phase and proceeds across the subsequent evolutionary phases. The chemical trail from cores to protoplanetary disks to planetary embryos can be studied by comparing distant ... More
The CARMENES search for exoplanets around M dwarfs - Photospheric parameters of target stars from high-resolution spectroscopyFeb 08 2018The new CARMENES instrument comprises two high-resolution and high-stability spectrographs that are used to search for habitable planets around M dwarfs in the visible and near-infrared regime via the Doppler technique. Characterising our target sample ... More
Limitation of atmospheric composition by combustion-explosion in exoplanetary atmospheresFeb 08 2018This work presents theoretical studies which combine aspects of combustion and explosion theory with exoplanetary atmospheric science. Super Earths could possess a large amount of molecular hydrogen depending on disk, planetary and stellar properties. ... More
Ground-based lightcurve observation campaign of (25143) Itokawa between 2001 and 2004Feb 08 2018The asteroid (25143) Itokawa is a target object of the Japanese sample return mission, HAYABUSA. We have observed Itokawa in optical wave- length (R-band) with the 1.05-m Schmidt telescope at the Kiso Observatory, the 2.24-m telescope of University of ... More
3D Meteoroid TrajectoriesFeb 08 2018Fireball observations from camera networks provide position and time information along the trajectory of a meteoroid that is transiting our atmosphere. The complete dynamical state of the meteoroid at each measured time can be estimated using Bayesian ... More
Characterization of dust activity on Mars from MY27 to MY32 by PFS-MEX observationsFeb 07 2018We present spatial and temporal distributions of dust on Mars from Ls = 331 in MY26 until Ls = 80 in MY33 retrieved from the measurements taken by the Planetary Fourier Spectrometer (PFS) aboard Mars Express. In agreement with previous observations, large ... More
Unlocking CO Depletion in Protoplanetary Disks I. The Warm Molecular LayerFeb 07 2018CO is commonly used as a tracer of the total gas mass in both the interstellar medium and in protoplanetary disks. Recently there has been much debate about the utility of CO as a mass tracer in disks. Observations of CO in protoplanetary disks reveal ... More
OGLE-2017-BLG-1434Lb: Eighth q < 1 * 10^-4 Mass-Ratio Microlens Planet Confirms Turnover in Planet Mass-Ratio FunctionFeb 07 2018We report the discovery of a cold Super-Earth planet (m_p=4.4 +/- 0.5 M_Earth) orbiting a low-mass (M=0.23 +/- 0.03 M_Sun) M dwarf at projected separation a_perp = 1.18 +/- 0.10 AU, i.e., about 1.9 times the snow line. The system is quite nearby for a ... More
The Chemical Homogeneity of Sun-like Stars in the Solar NeighborhoodFeb 07 2018The compositions of stars are a critical diagnostic tool for many topics in astronomy such as the evolution of our Galaxy, the formation of planets, and the uniqueness of the Sun. Previous spectroscopic measurements indicate a large intrinsic variation ... More
Target selection for a small low-thrust mission to near-Earth asteroidsFeb 07 2018The preliminary mission design of spacecraft missions to asteroids often involves, in the early phases, the selection of candidate target asteroids. The final result of such an analysis is a list of asteroids, ranked with respect to the necessary propellant ... More
Why is Interstellar Object 1I/2017 U1 (`Oumuamua) Rocky, Tumbling and Very Prolate?Feb 07 2018The recently discovered first interstellar object 1I/2017 U1 (`Oumuamua) has brightness that varies by a factor of 10, a range greater than that of any Solar System asteroid, a spectrum characteristic of Type D asteroids, and no evidence of evaporating ... More
Atmospheric reconnaissance of the habitable-zone Earth-sized planets orbiting TRAPPIST-1Feb 06 2018Seven temperate Earth-sized exoplanets readily amenable for atmospheric studies transit the nearby ultracool dwarf star TRAPPIST-1 (refs 1,2). Their atmospheric regime is unknown and could range from extended primordial hydrogen-dominated to depleted ... More
Mars Thermospheric Variability Revealed by MAVEN EUVM Solar Occultations: Structure at Aphelion and Perihelion, and Response to EUV ForcingFeb 06 2018The Mars thermosphere holds clues to the evolution of the Martian climate, and has practical implications for spacecraft visiting Mars, which often use it for aerobraking upon arrival, or for landers, which must pass through it. Nevertheless, it has been ... More
Magma ascent in planetesimals: control by grain sizeFeb 06 2018Rocky planetesimals in the early solar system melted internally and evolved chemically due to radiogenic heating from aluminum-26. Here we quantify the parametric controls on magma genesis and transport using a coupled petrological and fluid mechanical ... More
An Analysis of Transiting Hot Jupiters Observed with K2: WASP-55b and WASP-75bFeb 06 2018We present our analysis of the K2 short-cadence data of two previously known hot Jupiter exoplanets: WASP-55b and WASP-75b. The high precision of the K2 lightcurves enabled us to search for transit timing and duration variations, rotational modulation, ... More
The Near-Infrared Transmission Spectra of TRAPPIST-1 Planets b, c, d, e, f, and g and Stellar Contamination in Multi-Epoch Transit SpectraFeb 06 2018The seven approximately Earth-sized transiting planets in the TRAPPIST-1 system provide a unique opportunity to explore habitable zone and non-habitable zone small planets within the same system. Its habitable zone exoplanets -- due to their favorable ... More
Analytic Reflected Lightcurves for ExoplanetsFeb 06 2018The disk-integrated reflected brightness of an exoplanet changes as a function of time due to orbital and rotational motion coupled with an inhomogeneous albedo map. We have previously derived analytic reflected lightcurves for spherical harmonic albedo ... More
Large Synoptic Survey Telescope Solar System Science RoadmapFeb 06 2018The Large Synoptic Survey Telescope (LSST) is uniquely equipped to search for Solar System bodies due to its unprecedented combination of depth and wide field coverage. Over a ten-year period starting in 2022, LSST will generate the largest catalog of ... More
The Dynamics of Tightly-packed Planetary Systems in the Presence of an Outer Planet: case studies using Kepler-11 and Kepler-90Feb 05 2018We explore the effects of an undetected outer giant planet on the dynamics, observability, and stability of Systems with Tightly-packed Inner Planets (STIPs). We use direct numerical simulations along with secular theory and synthetic secular frequency ... More
ATLAS Probe: Breakthrough Science of Galaxy Evolution, Cosmology, Milky Way, and the Solar SystemFeb 05 2018ATLAS (Astrophysics Telescope for Large Area Spectroscopy) Probe is a concept for a NASA probe-class space mission, the spectroscopic follow-up to WFIRST, multiplexing its scientific return by obtaining deep 1 to 4 micron slit spectroscopy for ~90% of ... More
The nature of the TRAPPIST-1 exoplanetsFeb 05 2018Context. The TRAPPIST-1 system hosts seven Earth-sized, temperate exoplanets orbiting an ultra-cool dwarf star. As such, it represents a remarkable setting to study the formation and evolution of terrestrial planets that formed in the same protoplanetary ... More
Classifying and modelling spiral structures in hydrodynamic simulations of astrophysical discsFeb 05 2018We demonstrate numerical techniques for automatic identification of individual spiral arms in hydrodynamic simulations of astrophysical discs. Building on our earlier work, which used tensor classification to identify regions that were "spiral-like", ... More
Experimental Constraints On The Fatigue of Icy Satellite Lithospheres by Tidal ForcesFeb 05 2018Fatigue can cause materials that undergo cyclic loading to experience brittle failure at much lower stresses than under monotonic loading. We propose that the lithospheres of icy satellites could become fatigued and thus weakened by cyclical tidal stresses. ... More
Spinup and Disruption of Interstellar Asteroids by Mechanical Torques, and Implications for 1I/2017 U1 (`Oumuamua)Feb 05 2018The detection of the first interstellar asteroid, 1I/2017 U1 (`Oumuamua), has opened a new era for research on interstellar objects. In this paper, we study the rotational dynamics of interstellar asteroids (ISAs) of irregular shapes moving through the ... More
A search for technosignatures from 14 planetary systems in the Kepler field with the Green Bank Telescope at 1.15-1.73 GHzFeb 04 2018Analysis of Kepler mission data suggests that the Milky Way includes billions of Earth-like planets in the habitable zone of their host star. Current technology enables the detection of technosignatures emitted from a large fraction of the Galaxy. We ... More
Suppressed Far-UV Stellar Activity and Low Planetary Mass Loss in the WASP-18 SystemFeb 03 2018WASP-18 hosts a massive, very close-in Jupiter-like planet. Despite its young age ($<$1 Gyr), the star presents an anomalously low stellar activity level: the measured logR'$_{\rm HK}$ activity parameter lies slightly below the basal level; there is no ... More
Stability of the Euler Resting N-Body Relative EqulilbriaFeb 03 2018The stability of a system of $N$ equal sized mutually gravitating spheres resting on each other in a straight line and rotating in inertial space is considered. This is a generalization of the "Euler Resting" configurations previously analyzed in the ... More
Spectral Evidence for Amorphous Silicates in Least-processed CO Meteorites and Their Parent BodiesFeb 02 2018Least-processed carbonaceous chondrites (carbonaceous chondrites that have experienced minimal aqueous alteration and thermal metamorphism) are characterized by their predominately amorphous iron-rich silicate interchondrule matrices and chondrule rims. ... More
Discovery of WASP-174b: Doppler tomography of a near-grazing transitFeb 02 2018We report the discovery and tomographic detection of WASP-174b, a planet with a near-grazing transit on a 4.23-d orbit around a $V$ = 11.9, F6V star with [Fe/H] = 0.09 $\pm$ 0.09. The planet is in a moderately misaligned orbit with a sky-projected spin-orbit ... More
2MASS J13243553+6358281 is an Early T-Type Planetary-Mass Object in the AB Doradus Moving GroupFeb 01 2018We present new radial velocity and trigonometric parallax measurements indicating that the unusually red and photometrically variable T2 dwarf 2MASS J13243553+6358281 is a member of the young (~150 Myr) AB Doradus moving group based on its space velocity. ... More
OSSOS: X. How to use a Survey Simulator: Statistical Testing of Dynamical Models Against the Real Kuiper BeltFeb 01 2018All surveys include observational biases, which makes it impossible to directly compare properties of discovered trans-Neptunian Objects (TNOs) with dynamical models. However, by carefully keeping track of survey pointings on the sky, detection limits, ... More
Hidden Planetary Friends: On the Stability Of 2-Planet Systems in the Presence of a Distant, Inclined CompanionFeb 01 2018Recent observational campaigns have shown that multi-planet systems seem to be abundant in our Galaxy. Moreover, it seems that these systems might have distant companions, either planets, brown-dwarfs or other stellar objects. These companions might be ... More
The influence of a sub-stellar continent on the climate of a tidally-locked exoplanetFeb 01 2018Previous studies have demonstrated that continental carbon-silicate weathering is important to the continued habitability of a terrestrial planet. Despite this, few studies have considered the influence of land on the climate of a tidally-locked planet. ... More
Decrease in hysteresis of planetary climate for planets with long solar daysJan 31 2018The ice-albedo feedback on rapidly-rotating terrestrial planets in the habitable zone can lead to abrupt transitions (bifurcations) between a warm and a snowball (ice-covered) state, bistability between these states, and hysteresis in planetary climate. ... More
An improved quantification of HD 147379 bJan 31 2018We reanalyze the CARMENES and HIRES/KECK radial velocity data for HD 147379, and also analyze the SOPHIE data using the Agatha software in combination with MCMC posterior sampling. The analysis confirms the existence of HD 147379 b and improves the parameter ... More
An Improved Transit Measurement for a 2.4 $R_{\rm Earth}$ Planet Orbiting A Bright Mid-M Dwarf K2$-$28Jan 30 2018We present a new Spitzer transit observation of K2$-$28b, a sub-Neptune ($R_{\rm p} = 2.45\pm0.28 R_{\rm Earth}$) orbiting a relatively bright ($V_{\rm mag} = 16.06$, $K_{\rm mag} = 10.75$) metal-rich M4 dwarf (EPIC 206318379). This star is one of only ... More
High Abundances of Presolar Grains and $^{15}$N-rich Organic Matter in CO3.0 Chondrite Dominion Range 08006Jan 30 2018NanoSIMS C-, N-, and O-isotopic mapping of matrix in CO3.0 chondrite Dominion Range (DOM) 08006 revealed it to have in its matrix the highest abundance of presolar O-rich grains (257 +76 / -96 ppm, 2$\sigma$) of any meteorite. It also has a matrix abundance ... More
Large Starspot Groups on HAT-P-11 in Activity Cycle 1Jan 30 2018HAT-P-11 is a planet-hosting K4V star in the Kepler field, with an activity cycle that bear similarities to the Sun's. The chromospheric activity of HAT-P-11 indicates that a new activity cycle is beginning. We report ground-based observations with holographic ... More
Bayesian Model Testing of Ellipsoidal Variations on Stars due to Hot JupitersJan 30 2018A massive planet closely orbiting its host star creates tidal forces that distort the typically spherical stellar surface. These distortions, known as ellipsoidal variations, result in changes in the photometric flux emitted by the star, which can be ... More
Olivine-Carbonate Mineralogy of Jezero CraterJan 30 2018A well-preserved, ancient delta deposit, in combination with ample exposures of Mg-carbonate rich materials, make Jezero Crater in Nili Fossae a compelling astrobiological site and a top candidate for future landed missions to Mars. We use CRISM observations ... More
Cloud Atlas: Rotational Modulations in the L/T Transition Brown Dwarf Companion HN Peg BJan 29 2018Time-resolved observations of brown dwarfs' rotational modulations provide powerful insights into the properties of condensate clouds in ultra-cool atmospheres. Multi-wavelength light curves reveal cloud vertical structures, condensate particle sizes, ... More
Exoplanet atmospheres with GIANO. I. Water in the transmission spectrum of HD 189733bJan 29 2018High-resolution spectroscopy (R $\ge$ 20 000) at near-infrared wavelengths can be used to investigate the composition, structure, and circulation patterns of exoplanet atmospheres. However, up to now it has been the exclusive dominion of the biggest telescope ... More
C/O vs Mg/Si ratios in solar type stars: The HARPS sampleJan 29 2018Aims. We present a detailed study of the Mg/Si and C/O ratios and their importance in determining the mineralogy of planetary companions. Methods. Using 499 solar-like stars from the HARPS sample, we determine C/O and Mg/Si elemental abundance ratios ... More
EURONEAR - First Light Curves and Physical Properties of Near Earth AsteroidsJan 29 2018Part of the European Near Earth Asteroids Research (EURONEAR) project, in 2014 we started a survey to observe light curves of Near Earth Asteroids (NEAs) using the available telescopes of this network. This is the first paper presenting light-curves and ... More
The Wavelet theory applied to the study of spectra of Trans-Neptunian objectsJan 27 2018Reflection spectroscopy in the Near Infrared (NIR) is used to investigate the surface composition of Trans-Neptunian objects (TNOs). In general, these spectra are difficult to interpret due to the low apparent brightness of the TNOs, causing low signal-to-noise ... More
Saltation under Martian Gravity and its Influence on the Global Dust DistributionJan 26 2018Dust and sand motion are a common sight on Mars. Understanding the interaction of atmosphere and Martian soil is fundamental to describe the planet's weather, climate and surface morphology. We set up a wind tunnel to study the lift of a mixture between ... More
Planet Occurrence: Doppler and Transit SurveysJan 25 2018Prior to the 1990s, speculations about the occurrence of planets around other stars were based only on planet formation theory, observations of circumstellar disks, and the knowledge that at least one seemingly ordinary star had managed to make a variety ... More
Dust in brown dwarfs and extra-solar planets VI. Assessing seed formation across the brown dwarf and exoplanet regimesJan 25 2018The cloud formation process starts with the formation of seed particles, after which, surface chemical reactions grow or erode the cloud particles. We investigate which materials may form cloud condensation seeds in the gas temperature and pressure regimes ... More
Triggering the Activation of Main Belt Comets: The Effect of PorosityJan 25 2018It has been suggested that the comet-like activity of Main Belt Comets is due to the sublimation of sub-surface water-ice that is exposed when these objects are impacted by meter-sized bodies. We recently examined this scenario and showed that such impacts ... More
The KMTNet/K2-C9 (Kepler) Data ReleaseJan 24 2018Jan 26 2018We present Korea Microlensing Telescope Network (KMTNet) light curves for microlensing-event candidates in the Kepler K2 C9 field having peaks within 3 effective timescales of the Kepler observations. These include 181 "clear microlensing" and 84 "possible ... More
Jupiter's evolution with primordial composition gradientsJan 24 2018Recent formation and structure models of Jupiter suggest that the planet can have composition gradients and not be fully convective (adiabatic). This possibility directly affects our understanding of Jupiter's bulk composition and origin. In this Letter ... More
Searching sub-stellar objects in DR1-TGAS, effectiveness and efficiency of Gaias' astrometryJan 24 2018We used 1,477,047 data from DR1-TGAS, in order to analyse the minimum require- ments of accuracy, necessary to detect sub-stellar objects in the astrometric mea- surements of Gaia. We found that the first set of data (DR1) does not have enough accuracy, ... More
Characterizing the variable dust permeability of planet-induced gapsJan 24 2018Jan 25 2018Aerodynamic theory predicts that dust grains in protoplanetary disks will drift radially inward on comparatively short timescales. In this context, it has long been known that the presence of a gap opened by a planet can alter the dust dynamics significantly. ... More
EPIC229426032 b and EPIC246067459 b: discovery of a highly inflated and a 'regular' pair of transiting hot Jupiters from K2Jan 24 2018We report the discovery of two hot Jupiters orbiting the stars EPIC229426032 and EPIC246067459. We used photometry data from Campaign 11 and 12 of the Kepler (K2) Mission, as well as radial velocity data obtained using the HARPS, FEROS, and CORALIE spectrographs. ... More
The co-existence of hot and cold gas in debris discsJan 24 2018Debris discs have often been described as gas-poor discs as the gas-to-dust ratio is expected to be considerably lower than in primordial,protoplanetary discs. However, recent observations have confirmed the presence of a non-negligible amount of cold ... More
Torques Induced by Scattered Pebble-flow in Protoplanetary DisksJan 24 2018In the current planet formation paradigm, gravitational torques exerted by the gas in protoplanetary disks play a central role in determining the long-term orbital evolution of planetary embryos. Even though dust is ubiquitous in these systems, its dynamical ... More
Unexpected cyclic behavior in cosmic ray protons observed by PAMELA at 1 AUJan 24 2018Protons detected by the PAMELA experiment in the period 2006-2014 have been analyzed in the energy range between 0.40-50 GV to explore possible periodicities besides the well known solar undecennial modulation. An unexpected clear and regular feature ... More
A Wideband Self-Consistent Disk-Averaged Spectrum of Jupiter Near 30 GHz and Its Implications for NH$_{3}$ Saturation in the Upper TroposphereJan 23 2018We present a new set of measurements obtained with the Combined Array for Research in Millimeter-wave Astronomy (CARMA) of Jupiter's microwave thermal emission near the 1.3 cm ammonia (NH$_{3}$) absorption band. We use these observations to investigate ... More
A dynamical context for the origin of Phobos and DeimosJan 23 2018We show that a model in which Mars grows near Earth and Venus but is then scattered out of the terrestrial region yields a natural pathway to explain the low masses of the Martian moons Phobos & Deimos. In this scenario, the last giant impact experienced ... More
A search for radio emission from exoplanets around evolved starsJan 23 2018The majority of searches for radio emission from exoplanets have to date focused on short period planets, i.e., the so-called hot Jupiter type planets. However, these planets are likely to be tidally locked to their host stars and may not generate sufficiently ... More
Sulfidic Anion Concentrations on Early Earth for Surficial Origins-of-Life ChemistryJan 23 2018A key challenge in origin-of-life studies is understanding the environmental conditions on early Earth under which abiogenesis occurred. While some constraints do exist (e.g., zircon evidence for surface liquid water), relatively few constraints exist ... More
Pebble dynamics and accretion onto rocky planets. I. Adiabatic and convective modelsJan 23 2018Jan 25 2018We present nested-grid, high-resolution hydrodynamic simulations of gas and particle dynamics in the vicinity of Mars- to Earth-mass planetary embryos. The simulations extend from the surface of the embryos to a few vertical disk scale heights, with dynamic ... More
Discovery of a Transiting Adolescent Sub-Neptune Exoplanet in the Cas-Tau Association with K2Jan 22 2018The role of stellar age in the measured properties and occurrence rates of exoplanets is not well understood. This is in part due to a paucity of young planets and the uncertainties in age-dating for most exoplanet host stars. Exoplanets belonging to ... More
Dependence of the onset of the runaway greenhouse effect on the latitudinal surface water distribution of Earth-like planetsJan 22 2018Liquid water is one of the most important materials affecting the climate and habitability of a terrestrial planet. Liquid water vaporizes entirely when planets receive insolation above a certain value, which is called the runaway greenhouse threshold. ... More
K2-155: A Bright Metal-Poor M Dwarf with Three Transiting Super-EarthsJan 22 2018Jan 24 2018We report on the discovery of three transiting super-Earths around K2-155 (EPIC 210897587), a relatively bright early M dwarf ($V=12.81$ mag) observed during Campaign 13 of the NASA K2 mission. To characterize the system and validate the planet candidates, ... More
Evaluation of the Interplanetary Magnetic Field Strength Using the Cosmic-Ray Shadow of the SunJan 22 2018We analyze the Sun's shadow observed with the Tibet-III air shower array and find that the shadow's center deviates northward (southward) from the optical solar disc center in the "Away" ("Toward") IMF sector. By comparing with numerical simulations based ... More
A procedure for observing rocky exoplanets to maximize the likelihood that atmospheric oxygen will be a biosignatureJan 22 2018Here we advocate an observational strategy to help prioritize exoplanet observations. It starts with more easily obtained observational data, and ranks exoplanets for more difficult follow-up observations based on the likelihood of avoiding planets for ... More
Raman Detection Threshold Measurements for Acetic Acid in Martian Regolith Simulant JSC-1 in the Presence of Hydrated Metallic SulfatesJan 21 2018Several measurements, including the data from the laser spectrometer in the Sample Analysis at Mars instrument suite on the Curiosity Rover in Gale crater, have measured seasonal variations in atmospheric methane at the 0.7 ppbv (parts per billion volume) ... More
No Escape from the Supernova! Magnetic Imprisonment of Dusty Pinballs by a Supernova RemnantJan 21 2018Motivated by recent measurements of deposits of $^{60}$Fe on the ocean floor and the lunar surface, we model the transport of dust grains containing $^{60}$Fe from a near-Earth (i.e., within 100 pc) supernova (SN). We inject dust grains into the environment ... More
Life Beyond the Solar System: Remotely Detectable BiosignaturesJan 20 2018For the first time in human history, we will soon be able to apply the scientific method to the question "Are We Alone?" The rapid advance of exoplanet discovery, planetary systems science, and telescope technology will soon allow scientists to search ... More
Mesospheric optical signatures of possible lightning on VenusJan 20 2018A self-consistent two-dimensional model is proposed to account for the transient mesospheric nighttime optical emissions associated to possible intra-cloud (IC) lightning occurring in the Venusian troposphere. The model calculates the mesospheric (between ... More
Detection of a Westward Hotspot Offset in the Atmosphere of a Hot Gas Giant CoRoT-2bJan 19 2018Short-period planets exhibit day-night temperature contrasts of hundreds to thousands of degrees K. They also exhibit eastward hotspot offsets whereby the hottest region on the planet is east of the substellar point; this has been widely interpreted as ... More
Haze Production in the Atmospheres of super-Earths and mini-Neptunes: Insights from the LabJan 19 2018Numerous solar system atmospheres possess aerosols including the characteristic organic hazes of Titan and Pluto. Haze particles substantially impact atmospheric temperatures structures and may provide organic material to the surface of a world, thereby ... More
A system of three transiting super-Earths in a cool dwarf starJan 18 2018We present the detection of three super-Earths transiting the cool star LP415-17, monitored by K2 mission in its 13th campaign. High resolution spectra obtained with HARPS-N/TNG showed that the star is a mid-late K dwarf. Using spectral synthesis models ... More
K2 reveals pulsed accretion driven by the 2 Myr old hot Jupiter CI Tau bJan 18 2018CI Tau is a young (~2 Myr) classical T Tauri star located in the Taurus star forming region. Radial velocity observations indicate it hosts a Jupiter-sized planet with an orbital period of approximately 9 days. In this work, we analyze time series of ... More
GPI Spectroscopy of the Mass, Age, and Metallicity Benchmark Brown Dwarf HD 4747 BJan 18 2018The physical properties of brown dwarf companions found to orbit nearby, solar-type stars can be benchmarked against independent measures of their mass, age, chemical composition, and other parameters, offering insights into the evolution of substellar ... More
Kepler Object of Interest Network I. First results combining ground and space-based observations of Kepler systems with transit timing variationsJan 18 2018During its four years of photometric observations, the Kepler space telescope detected thousands of exoplanets and exoplanet candidates. One of Kepler's greatest heritages has been the confirmation and characterization of hundreds of multi-planet systems ... More
New insights into the nature of transition disks from a complete disk survey of the Lupus star forming regionJan 18 2018Transition disks with large dust cavities around young stars are promising targets for studying planet formation. Previous studies have revealed the presence of gas cavities inside the dust cavities hinting at recently formed, giant planets. However, ... More
Origins of Hot JupitersJan 18 2018Hot Jupiters were the first exoplanets to be discovered around main sequence stars and astonished us with their close-in orbits. They are a prime example of how exoplanets have challenged our textbook, solar-system inspired story of how planetary systems ... More
Investigating the young Solar System analog HD95086Jan 17 2018HD95086 (A8V, 17Myr) hosts a rare planetary system for which a multi-belt debris disk and a giant planet of 4-5MJup have been directly imaged. Our study aims to characterize the physical and orbital properties of HD95086b, search for additional planets ... More
Finding Mountains with Molehills: The Detectability of ExotopographyJan 17 2018Mountain ranges, volcanoes, trenches, and craters are common on rocky bodies throughout the Solar System, and we might we expect the same for rocky exoplanets. With ever larger telescopes under design and a growing need to not just detect planets but ... More
Rings and gaps in the disc around Elias 24 revealed by ALMAJan 17 2018We present Atacama Large Millimeter/sub-millimeter Array (ALMA) Cycle 2 observations of the 1.3 mm dust continuum emission of the protoplanetary disc surrounding the T Tauri star Elias 24 with an angular resolution of $\sim 0.2"$ ($\sim 28$ au). The dust ... More
Spitzer Microlensing Parallax for OGLE-2016-BLG-1067: a sub-Jupiter Orbiting an M-dwarf in the DiskJan 17 2018We report the discovery of a sub-Jupiter mass planet orbiting beyond the snow line of an M-dwarf most likely in the Galactic disk as part of the joint Spitzer and ground-based monitoring of microlensing planetary anomalies toward the Galactic bulge. The ... More
Towards a theoretical determination of the geographical probability distribution of meteoroid impacts on EarthJan 17 2018Tunguska and Chelyabinsk impact events occurred inside a geographical area of only 3.4\% of the Earth's surface. Although two events hardly constitute a statistically demonstration of a geographical pattern of impacts, their spatial coincidence is at ... More
Forecasting the detectability of known radial velocity planets with the upcoming CHEOPS missionJan 17 2018The Characterizing Exoplanets Satellite (CHEOPS) mission is planned for launch next year with a major objective being to search for transits of known RV planets, particularly those orbiting bright stars. Since the radial velocity method is only sensitive ... More
The Delivery of Water During Terrestrial Planet FormationJan 16 2018The planetary building blocks that formed in the terrestrial planet region were likely very dry, yet water is comparatively abundant on Earth. We review the various mechanisms proposed for the origin of water on the terrestrial planets. Various in-situ ... More
Activity of (2060) Chiron possibly caused by impacts?Jan 16 2018The centaur 95P/(2060) Chiron is showing comet-like activity since its discovery, but the mass-loss mechanisms triggering its activity remained unexplained. Although the collision rates in the centaur region are expected to be very low, and impacts are ... More
HD 104860 and HD 192758: two debris disks newly imaged in scattered-light with HSTJan 16 2018We present the first scattered-light images of two debris disks around the F8 star HD 104860 and the F0V star HD 192758, respectively $\sim45$ and $\sim67$ pc away. We detected these systems in the F110W and F160W filters through our re-analysis of archival ... More
Life Beyond the Solar System: Space Weather and Its Impact on Habitable WorldsJan 16 2018The search of life in the Universe is a fundamental problem of astrobiology and a major priority for NASA. A key area of major progress since the NASA Astrobiology Strategy 2015 (NAS15) has been a shift from the exoplanet discovery phase to a phase of ... More
Origin of orbits of secondaries in the discovered trans-Neptunian binariesJan 16 2018The dependences of inclinations of orbits of secondaries in the discovered trans-Neptunian binaries on the distance between the primary and the secondary, on the eccentricity of orbits of the secondary around the primary, on the ratio of diameters of ... More
Formation of trans-Neptunian satellite systems at the stage of condensationsJan 16 2018The formation of trans-Neptunian satellite systems at the stage of rarefied preplanetesimals (i.e., condensations of dust and/or objects less than 1 m in diameter) is discussed. It is assumed that trans-Neptunian objects (including those with satellites) ... More
Production and fate of the G ring arc particles due to Aegaeon (Saturn LIII)Jan 15 2018The G ring arc hosts the smallest satellite of Saturn, Aegaeon, observed with a set of images sent by Cassini spacecraft. Along with Aegaeon, the arc particles are trapped in a 7:6 corotation eccentric resonance with the satellite Mimas. Due to this resonance, ... More
Tracking Advanced Planetary Systems (TAPAS) with HARPS-N. VI. HD 238914 and TYC 3318-01333-1 - two more Li-rich giants with planetsJan 13 2018Jan 16 2018We present the latest results of our search for planets with HARPS-N at the 3.6 m Telescopio Nazionale Galileo under the Tracking Advanced Planetary Systems project: an in-depth study of the 15 most Li abundant giants from the PennState - Toru\'n Planet ... More
Crater mound formation by wind erosion on MarsJan 12 2018Most of Mars' ancient sedimentary rocks by volume are in wind-eroded sedimentary mounds, but the connections between mound form and wind erosion are unclear. We perform mesoscale simulations of different crater and mound morphologies to understand the ... More
Space-based infrared interferometry to study exoplanetary atmospheresJan 12 2018The quest for other habitable worlds and the search for life among them are major goals of modern astronomy. One way to make progress towards these goals is to obtain high-quality spectra of a large number of exoplanets over a broad range of wavelengths. ... More
The path towards high-contrast imaging with the VLTI: the Hi-5 projectJan 12 2018The development of high-contrast capabilities has long been recognized as one of the top priorities for the VLTI. As of today, the VLTI routinely achieves contrasts of a few 10$^{-3}$ in the near-infrared with PIONIER (H band) and GRAVITY (K band). Nulling ... More