bluuebunny/crossref_metadata_2025 huggingface dataset:
Importance of citizen Czech Astronomical Society for variable star and exoplanet research
Authors: Honkova Katerina , Walter Filip
Published: October 2020

Variable Star and Exoplanet Section of Czech Astronomical Society (VSES CAS) is a citizen astronomy organization with almost century tradition in basic and advanced research on variable stars in Czech Republic. Members are formed both amateur and professional astronomers all age groups, including youths and students. VSES CAS is primary focus on observing variable stars and exoplanet, education and training of astronomers. The society annually organizes workshops, meetings or conferences for astronomers and many popularisation activities intended for general public. Many amateur astronomers also meaningfully contribute to professional astronomy with unquenchable enthusiasm, precise photometry reduction or acquiring photometric data with hardware similar to professional surveys. Some of the VSES projects have global impact. Database B.R.N.O. collects data of light curves of eclipsing binaries from observers. Since 2007, more then 19,000 minima timings from hundreds observers has saved to database. After revision, the contribution of times of minima are regularly published in Open European Journal of Variable Star. Project MEDUZA was focused on long-period variable stars. The database contains observations more then 1346 objects obtained both visual and CCD methods. The most important international project is Exoplanet Transit Database (ETD). The database administrators are periodically checking for new transits - both in literature and in on-line internet sources. The ETD also offers modern online fitting tool for publication of data of observers. Observers can plot their own observations in diagrams, finding out parameters HJDmid, depth, duration or global transit predictions. From 2008 to now, more then 8400 transits observed by observers from around the world are published in ETD. The members of VSES CAS operate and develop the observing remote-controlled setup of Newton 150/750 telescope and cooled CCD camera situated in Valasske Mezirici Observatory. The telescope is used mostly for observing campaigns, cooperation with profesional astronomers or student research projects. The results obtained using this telescope was also published in several international projects. Recently, the telescope is mostly used for follow-up observations of TESS exoplanet candidates. In VSES, we have now started developing a new generation of our web application. One of the goals is improved user experience and consolidation services, which were put together over a long time and using some now outdated technologies. New applications should reflect recent trends in modern astronomy and represent complete service for data processing, publishing observations, cloud storage, platform for campaigns and projects also social network between observers in around the world. New pro-am international cooperation on projects of variable stars and exoplanet, and important results of VSES members will be also presented.
Constraints on Io’s interior by combining small- and large-scale characteristics of the volcanic pattern
Authors: Steinke Teresa , van Sliedregt Duncan , Vilella Kenny , van der Wal Wouter , Vermeersen Bert
Published: October 2020

Intensive tidal heating makes the Galilean satellite Io to an outstanding example of a volcanically active world. Most of the heat generated in the interior is lost through a large number of active volcanoes. The distribution of Io's volcanoes on the surface could help us to constrain properties below Io’s crust, regulating the heat transport mechanism. For this study, we assume that (1) the presence of global volcanism is linked to the presence of melt in the upper mantle; that (2) the large-scale variation in volcanic density is inherited from non-uniform tidal heating and smoothed by vigorous convection; and that (3) the total number of hot-spots is controlled by the spatial frequency of thermal instabilities in the convecting layer. Three unknown parameters are explored: the fraction of convective heat transport compared to magmatic heat transport, the mantle viscosity, and the thickness of the heated layer. In order to evaluate which combinations of interior properties can explain Io's present volcanic distribution, we develop a model based on parameterised heat flow scalings to approximate different spatial characteristics of Io's interior convection pattern. Our model combines internal heating, and convective and magmatic heat flow. Parts of the parameter space that are not in agreement with the observation-derived conditions are ruled out.Our results show that the observed small- and large-scale characteristics of Io's volcanic pattern can be explained by sub-lithospheric anomalies caused by convection. Solutions that allow for active volcanism and Io's specific large-scale variations in volcanic activity range from a thick mantle of high viscosity (1017 Pa s) to a thin asthenosphere of low viscosity (1012 Pa s). If Io's volcanos are correlated to the spatial frequency of thermal instabilities, the range of Io's total volcanic features between 250 and 3030 can further constrain the parameter space. This favours a mantle with a low melt fraction, a low mantle viscosity, and a magmatic heat transport of >80%.
Laser Processing of Asteroid Simulants
Authors: Anthony Niklas , Granvik Mikael , Wanhainen Christina , Frostevarg Jan , Suhonen Heikki , Penttilä Antti
Published: October 2020

Asteroid mining and redirection are two trends that both can utilize lasers, one to drill and cut, the other to ablate and move. Yet little is known about what happens when a laser is used to process the types of materials we typically expect to find on most asteroids. To shed light on laser processing of asteroid material, we used pulsed Nd:YAG lasers on samples of olivine, pyroxene, and serpentine, and studied the process with a high-speed camera and illumination laser at 10~000~frames~per~second. We also measure the sizes of the resulting holes using X-ray micro-tomography to find the pulse parameters which remove the largest amount of material using the least amount of energy. We find that at these power densities, all three minerals will melt and chaotically throw off spatter. Short, low-power pulses can efficiently produce thin, deep holes, and long, high-power pulses are more energy efficient at removing the most amount of material. We wil also present some preliminary results of the effects of spallation of these materials.
Monitoring of the temporal evolution of water vapor in the stratosphere of Jupiter with the Odin space telescope between 2002 and 2019
Authors: Benmahi Bilal , Cavalié Thibault , Dobrijevic Michel , Biver Nicolas , Bermudez Diaz Kenneth , Sandqvist Aage , Lellouch Emmanuel , Moreno Raphael , Fouchet Thierry , Hue Vincent , Hartogh Paul , Billebaud Francoise , Lecacheux Alain , Hjalmarson Ake , Frisk Urban , Olberg Michael
Published: October 2020

In July 1994, comet Shoemaker-Levy 9 collided with Jupiter. This has introduced new chemical species into Jupiter’s atmosphere, notably H2O. We observed the disk-averaged emission H2O in Jupiter’s stratosphere at 556.936 GHz between 2002 and 2019 with the Odin space telescope with the initial goal of better constraining vertical eddy mixing (Kzz) in the layers probed by our observations (0.2-5 mbar).
The Odin observations show a decrease of about 40% of the line emission from 2002 to 2019. We analyzed these observations by combining a 1D photochemical model with a radiative transfer model to constrain the vertical eddy diffusion Kzz in the stratosphere of Jupiter. We were able to reproduce this decrease by modifying a well-established Kzz profile, in the 0.2 mbar to 5 mbar pressure range. However, the Kzz obtained is incompatible with observations of the main hydrocarbons. We found that even if we increase locally the initial abundances of H2O and CO at impact, the photochemical conversion of H2O and CO to CO2 does not allow us to find the observed decrease of the H2O emission line over time, suggesting that there is another loss mechanism. We propose that auroral chemistry, not accounted for in our model, as a promising candidate to explain the loss of H2O seen by Odin. Modeling the temporal evolution of the chemical species deposited by comet SL9 in the atmosphere of Jupiter with a 2D photochemical model would be the next step in this study.
Earth's thermospheric evolution and implications for planetary habitability
Authors: Johnstone Colin
Published: October 2020

During the Archean eon from 3.8 to 2.5 billion years ago, the Earth's upper atmosphere and interactions with the magnetosphere and the solar wind were likely significantly different to how it is today due to major differences in the chemical composition of the atmosphere and the younger Sun being signifcantly more active. Understanding these factors is important for understanding the evolution of planetary atmospheres within our solar system and beyond. While the higher activity of the Sun would have caused additional heating and expansion of the atmosphere, geochemical measurements show that carbon dioxide was far more abundant during this time and this would have led to significantly thermospheric cooling which would have protected the atmosphere from losses to space. I will present a study of the effects of the carbon dioxide composition and the Sun's activity evolution on the thermosphere and ionosphere of the Archean Earth, studying for the first time the effects of different scenarios for the Sun's activity evolution. I will show the importance of these factors for the exosphere and escape processes of the Earth and terrestrial planets outside our solar system.
Assessing slope precision from numerical propagation of DEM (Digital Elevation Model) vertical errors
Authors: Millot Cédric , Quantin-Nataf Cathy , Leyrat Cédric
Published: October 2020

Digital Elevation Models (DEM) are widely used tools in planetary sciences. Geometric parameters such as pixel orientations and local slopes can be derived from these DEM. However, as any data, DEM have a limited precision (i.e. errors), which yields to the propagation of errors on geometric parameters. Assessing local slopes is necessary for many morphological studies: then, how do the DEM vertical errors propagate on the slope values? To answer to this question, we develop a simple and fast numerical method based on the addition of noise on synthetic DEM. We evaluate the different components of slope errors to define the relationship between input DEM noise and output slope errors. Results can be used as first order estimations to discuss slope maps precision.
A comparison analysis for the determination of stellar parameters of Ariel targets
Authors: Brucalassi Anna
Published: October 2020

   Ariel has been selected as the next ESA M4 science mission and it will observe the atmospheres of a large and diversified population of transiting exoplanets. Key factor for the achievement of the scientific goal of ARIEL is the selection strategy for the definition of the input target list. A meaningful choice of the targets requires an accurate knowledge of the planet hosting star properties and this is necessary to be obtained well before the launch.We present the results of a bench-marking analysis between three different spectroscopic techniques used to determine stellar parameters for a selected number of targets belonging to the Ariel reference sample.Our goal is to consolidate a method that will be used to homogeneously determine the stellar parameters of the complete Ariel reference sample.
Requirements and design of a dual, thermal ion-electron instrument for an outer heliosphere and interstellar mission
Authors: Lavraud Benoit , Fedorov Andrei , Blanc Michel , Wimmer-Schweingruber Robert , Zong Qiugang , McNutt Ralph , Brandt Pontus
Published: October 2020

We present the scientific rationale, and ensuing requirements, for the measurement of thermal ions and electrons in the solar wind (including pick-up ions), the inner and outer heliosphere, and the interstellar medium. We place these in the context of the interstellar missions being currently designed in the US and China. From these requirements, we propose an instrument concept that permits to measure both thermal ions (without composition) and electrons, alternatively, with low resources and high signal-to-noise ratio in accordance with the limited resources and large range of count rates, as expected over the course of such a mission.
Dust tail observation and modeling of the interstellar comet 2I/Borisov
Authors: Cremonese Gabriele , Fulle Marco , Cambianica Pamela , Munaretto Giovanni , Capria Maria Teresa , La Forgia Fiorangela , Lazzarin Monica , Migliorini Alessandra , Boschin Walter
Published: October 2020

On 30 August 2019 the amateur Borisov discovered a new comet; after few days it was clear from the characteristics of its orbit (eccentricity > 3 and high hyperbolic excess velocity) that the second interstellar object had been detected and the object received the name of 2I/Borisov. It appears to be very different from 1I/’Oumuamua and can be considered as the first interstellar comet.According to the first observations the comet had a nucleus with a radius of few km and a dust coma and tail due to the activity started in June 2019 (Jewitt et al., 2019).At the beginning of October we submitted the Discretionary Director Time (DDT) proposal to the TNG in order to monitor the comet. Some images have been acquired, in November and December 2019, with the DOLORES instrument in the R filter.We have applied the dust model described in Fulle et al. (2010), that has been tested on the comet 67P/Churyumov-Gerasimenko and validated with the Rosetta measurements.According to the results of our dust model and the activity model (Fulle et al., 2020) we derived a water flux from the nucleus of 8x10-6 kg m-2 s-1 and a dust loss rate of 35 and 30 kg s-1 in November and December 2019 respectively (Cremonese et al., 2020). This slight decrease has been observed around the perihelion on 8 December, few months later the comet fragmented.In this work we will describe the dust tail observations and the dust model results, even comparing them with the Jupiter family comet 67P.References:G.Cremonese, et al., 2020, ApJL, 893, L12M.Fulle et al., 2010, A&A, 522, A63.M.Fulle et al., 2020, MNRAS, 493, 4039.Jewitt et al., 2019, ApJ, 886, L29.
Morphology and time evolution of observed mid-latitude clouds on Titan as tracers of storm types, waves and instabilities.
Authors: Arias-Young Tersi , Mitchell Jonathan
Published: October 2020

ABSTRACTExamining the morphologies of Titan’s clouds can provide a general physical interpretation of observed storms and their relation to atmospheric dynamics of the moon. Through a combined analysis of observations of images collected by Cassini ISS during Titan flybys, we search for cloud phenomena to identify various types of storms. Several of the observed cloud features also give us both spatial and temporal information that reveals how the clouds evolve in time. We employ the cloud activity of the observed clouds to describe their characteristics and search for time evolution patterns to try to identify the dynamics behind them, for instance Rossby and gravity waves.Observations of a predominant example of a mid-latitude cloud system was captured by Cassini ISS cameras over a period of about 24 hours from Dec. 13 to 14, 2009, after the onset of a new season of the Saturn system. The images show methane clouds in the troposphere concentrated in a band between 45o and 63o south latitude, a streak-shaped mid-latitude cloud system extending across half the globe, traveling several hundred kilometers during the observation period. The sequence of images obtained throughout this flyby allowed us to create maps (see image below) that were made into movies of clouds moving across the moon's surface background.We present the analysis of these  “streamer clouds”, as we have dubbed them, and a handful of other mid-latitude cloud system events based on observations of the movies produced from their ISS-mapped images. The results of the analysis and the implications for Titan's atmospheric instabilities will be discussed.
Quasi-thermal noise, plasma wave, and radio measurements for an Interstellar Probe Mission
Authors: Bale Stuart , Kurth William
Published: October 2020

A well-designed radio and plasma wave instrument on Interstellar Probe will measure a variety of key phenomena in the outer heliosphere and interstellar medium, namely few-kHz radio emissions from beyond the heliopause, quasi-thermal noise emissions - hence plasma density and temperature, plasma waves associated local kinetics and beams, and potentially dust impacts on the spacecraft.  Radio emission signatures have been observed as solar transients interact with the local interstellar medium and can give remote measurements of the interaction between the heliosphere and local interstellar medium.  The quasi-thermal noise spectrum is a highly accurate way to measure total density, electron pressure, and potentially bulk flow speed in the interstellar medium.  Nonthermal plasma waves are indication of electron beams and kinetic plasma distributions and can give key diagnostics of shocks, current sheets, and other discontinuities.  And of course, plasma wave measurements have proved to be a simple, robust measure of dust statistics with a relatively large count rate.  All of these science goals can be met with a simple radio and plasma wave instrument, provided that proper consideration is given to sensor design and geometry and spacecraft integration is considered a priori.  We describe the science and instrument trades and resource estimates associated with such an instrument.  
Observe the Sky and draw your emotions
Authors: Giacomini Livia , Cutispoto Giuseppe , Gargano Mauro , Wolter Anna
Published: October 2020

"Observe the Sky and draw your emotions" is an art competition for students organized in Italy by the National Institute for Astrophysics (INAF). Students of primary and secondary schools are invited to participate submitting their original drawings, paintings or 3Dmodels inspired by an astronomical object, by space exploration or just by observing the sky.The competition was started in 2007 by the Catania Astrophysical Observatory and in the following years it grew in participation, going from local to a national level. In 2020 it was transformed in a digital initiative, thanks to the collaboration of the Capodimonte Astronomical Observatory of Naples and of EduINAF, INAF's new Online Magazine dedicated to Public Engagment. For the first time, the competition was organized and hosted by an online portal and opened for participants across the all country, reaching over 330 drawings, paintings and 3D models submitted.In this video presentation we will highlight the 12 winners of the last edition and a selection of the most beautiful and original entries of the 2020 and previous editions, showing how the sky can inspire the youngest and give birth to a form of artistic expression.
Planets in a Room: an educational tool for Europlanet
Authors: Giacomini Livia , Aloisi Francesco , De Angelis Ilaria , Capretti Stefano
Published: October 2020

Planets in a room (PIAR) is a DIY kit to build a small, lowcost spherical planet simulator and planetarium projector. Teachers, science communicators that run a small museum or planetarium, planetary scientists, amateur astronomers and other individuals can easily build it and use it on their own, to show and teach the Earth and other planets and to develop and share material with a growing online community. Having started in 2017 with a first version made using 3d-printed technology, PIAR has lately gone green, with a new wooden, plastic-free version of the kit. (http://www.planetsinaroom.net/)The project has been developed by the italian non-profit association Speak Science, with the collaboration of the Italian National Institute for Astrophysics (INAF) and the Roma Tre University, Dipartimento di Matematica e Fisica.It was funded by the Europlanet Outreach Funding Scheme in 2017 and was presented to the scientific community at EPSC and other scientific Congresses in the following years. Today, it is being distributed to an increasing number of schools, science museum and research institutions. PIAR is also one of the projects selected by the Europlanet Society for education and public outreach of planetary science: in 2020, it is being distributed to the 12 Europlanet Regional Hubs all around Europe, to be used in a number of educational projects.In this talk we will review the state of the art of the project presenting a selection of educational material and projects that have been developed for PIAR by scientists, teachers and communicators and that are focused on planetary science and on planetary habitability. AcknowledgementsWe acknowledge for this project the vast community of amateur and professionals that is actively working on innovative educational systems for astronomy such as planetarium and virtual reality projects (both hardware and software). Planets in a room is based on the work of this vast community of people and their experiences and results. We also acknowledge Europlanet for funding this work: the project Europlanet 2024 RI has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 871149.” ReferencesGiacomini L., Aloisi F., De Angelis I., “Planets in a room”, EPSC Abstracts Vol. 11, EPSC2017-280, 2017Giacomini L., Aloisi F., De Angelis I., Capretti S., “Planets in a Room: a DIY, low-cost educational kit”, EPSC Abstracts Vol. 12, EPSC2018-254, 2018Giacomini L., Aloisi F., De Angelis I., Capretti S., “Planets on (low-cost) balloons”, EPSC AbstractsVol. 13, EPSC-DPS2019-1243-1, 2019Giacomini L., Aloisi F., De Angelis I., Capretti S, “(Green) Planets in a Room”, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-22153, https://doi.org/10.5194/egusphere-egu2020-22153, 202
The Astromaterials Data System: Advancing Access to Past, Present, and Future Lab Analytical Data of NASA's Astromaterials Collections
Authors: Lehnert Kerstin , Ji Peng , Mays Jennifer , Figueroa Juan David , Johansson Annika , Profeta Lucia , Song Lulin , Morrison Shaunna
Published: October 2020

The Astromaterials Data System (AstroMat) is a comprehensive data system for laboratory analytical data generated on astromaterials. The system will host all data generated on samples from the Astromaterials Collections curated at NASA's Johnson Space Center. AstroMat has been under development since late 2018 with funding from NASA and has been releasing versions of system components that can be used for searching content in AstroMat and for publishing astromaterials data. We will provide an update on the status of the AstroMat software ecosystems and its data content in this presentation.
AstroMat is designed as an ecosystem of interconnected web applications that provide human- and machine-readable interfaces to the data gathered and managed in the AstroMat data store. is a synthesis of all past, present, and future laboratory analytical data for the Lunar, Antarctic Meteorite, Cosmic Dust, Genesis, Hayabusa, Stardust, and Microparticle Impact collections that is being compiled from the literature and other data sources together with a wide range of information pertaining to the provenance of the analytical measurements (e.g., analytical instrumentation, laboratory, sample preparation procedures, instrument calibration, data reduction) and to the quality of the data. AstroDB includes all lab analytical data for Apollo samples that had previously been compiled in the MoonDB synthesis. Data from more than 800 references pertaining to samples from the Apollo Missions and lunar meteorites were already compiled as part of the MoonDB project and have been migrated to the new AstroDB.The serves as a trusted repository, where researchers can publish and archive lab analytical data for any astromaterials, not only those for NASA collections.
AstroMat features graphical interfaces for users to search, access, explore, visualize, analyze, and contribute data (AstroSearch, AstroRef, AstroPlot, AstroDesk, AstroRepo) and machine-actionable interfaces that connect the databases to internal and external software tools (AstroAPIs, RepoAPIs). We encourage the community to advise and inform us on the usability and functionality of the interfaces in order for AstroMat to meet its goals of furthering planetary science research.
Determining the mass of RV exoplanet candidates using Gaia
Authors: Kiefer Flavien , Hébrard Guillaume , Lecavelier Alain , Martoli Eder , Dalal Shweta , Vidal-Madjar Alfred
Published: October 2020

Mass is one of the most important parameters for determining the true nature of an astronomical object. Yet, many published exoplanets in on-line database, such as exoplanet.eu or the NASA exoplanet archive, still lacks a measurement of their true mass, in particular those detected thanks to radial velocity (RV) variations of their host star. For those, only the minimum mass, or m sin(i), is known, owing to the insensitivity of RVs to the inclination of the detected orbit compared to the plane-of-the-sky. The mass that is given in database is generally that of an assumed edge-on system (90 degrees), but many other inclinations are likely, even extreme values closer to 0 degree (face-on configuration). In such case, the mass of the published object could be strongly underestimated, even by 1 or 2 orders of magnitude. We used a recently developed tool, called GASTON (Kiefer et al. 2019b & 2019c), to take advantage of the voluminous Gaia astrometric database, in order to constrain the inclination and true mass of several hundreds of published exoplanet candidates (Kiefer et al. 2020, submitted). In this presentation, we will present the method and report on several exoplanet candidates reclassified in the stellar domain, among which unknown brown/M-dwarf. We also confirm the planetary nature of a few tens of candidates.
Characteristics of an hybrid atmosphere with disk-captured and degassing contributions over a rocky planet’s magma ocean. A modeling approach.
Authors: Nikolaou Athanasia , Mugnai Lorenzo , Herbort Oliver , Pascale Enzo , Woitke Peter
Published: October 2020

Motivation:   Early during their formation the planets capture an amount of atmosphere from the protoplanetary disk (Ikoma et al. 2018, Odert et al. 2018, Lammer et al. 2020, Kimura and Ikoma 2020). An additional proportion of their atmosphere is provided during the magma ocean stage by interior degassing. The latter mechanism is assumed to be the main provider of the final atmospheric mass. Its composition is compromised by the source silicate mineral and its chemical characterization (Gaillard and Scaillet 2014, Herbort et al. 2020).   Numerous studies support the degassing of the oxidized gas species H2O and CO2 as main contributions from the magma ocean phase (Abe and Matsui 1988, Abe 1993, Elkins-Tanton 2008, Schaefer et al. 2012, Lebrun et al. 2013, Lupu et al. 2014, Gaillard and Scaillet 2014, Salvador et al. 2017, Nikolaou et al. 2019). Previous work has also shown that H2O, in particular, plays a crucial role (Hamano et al. 2013, Katyal et al. 2019, Turbet et al. 2019) in thermal blanketing. H2O possibly leads to “long-term” (Hamano et al 2013) or “conditionally continuous” (Nikolaou et al. 2019) magma oceans that effectively cease to cool. Water also ties directly to the availability of hydrogen that drives hydrodynamic escape (Airapetian et al. 2017, Lammer et al. 2018). CO2 factors into both above processes, as well (Wordsworth and Pierrehumbert 2013, Odert et al. 2018). Constraining the H2O and CO2 abundances early after formation is indispensible to the planet’s thermal evolution and extensive modeling effort has been devoted to it. Their constraint would in particular help revisit which magma ocean types among transient-conditionally continuous-permanent (Nikolaou et al. 2019) are detectable in future exoplanetary missions (ARIEL, Tinetti et al. 2018; PLATO, Rauer et al. 2014). Method:   In this work we focus on the combination of degassed and disk-captured atmosphere under the assumption of chemical equilibrium. Using simulations from the 1D Convective Ocean of Magma Radiative Atmosphere and Degassing model (Nikolaou et al. 2019) we obtain the thermal evolution and degassing tracks of a rocky planet. In order to evaluate the chemical abundances under equilibrium conditions we employ the thermodynamical model GGchem (Woitke et al. 2018).   We explore the atmospheric conditions during the lifetime of a magma ocean under varying mineral compositions and protoplanetary disk contributions. We discuss the results in the context of the likely magma ocean types. A.N. and P.W. wish to thank the Erwin Schrödinger International Institute for Mathematics and Physics (ESI) of the University of Vienna, Thematic Programme on “Astrophysical Origins: Pathways from Star Formation to Habitable Planets” 2019, which enabled this collaboration.
Detecting the Yarkovsky effect using the GAIA DR2 catalogue
Authors: Dziadura Karolina , Oszkiewicz Dagmara , Bartczak Przemysław
Published: October 2020

The orbital motion of small bodies is affected by the Yarkovsky effect. First-time the effect was proposed by Yarkovsky in 1901 and then popularized by Öpik in 1950s. However, the first direct detection was only made in 2003 using radar observations. Nowadays there are hundreds of detections for NEAs and only a few for Main-Belt objects. In this work, I attempt to detect the Yarkovsky effect among multiple Main-Belt objects and other asteroids. I will show preliminary results for five asteroids using the OrbFit software.  OrbFit is a Fortran program for orbit propagation, ephemerides computation, orbit determination, close approach analysis, and impact monitoring. Orbits were calculated using FitObs with and without the Yarkovsky effect. Next, the ephemeris were computed for the times of GAIA observations and compared with the GAIA DR2 data.
Asynchronous and chaotic rotation for compact planetary systems
Authors: Correia Alexandre C. M. , Delisle Jean-Baptiste
Published: October 2020

We study the spin evolution of close-in planets in compact multi-planetary systems. The rotation period of these planets is often assumed to be synchronous with the orbital period due to tidal dissipation. Here we show that planet-planet perturbations can drive the spin of these planets into non-synchronous or even chaotic states. These asynchronous configurations are possible even for nearly circular orbits and will impact the habitability of these planets. We also present a very simple method to probe the spin dynamics from the orbital perturbations.
Rarity of Boulders on Mercury: Possible Causes
Authors: Kreslavsky Mikhail A. , Zharkova Anastasia , Gritsevich Maria
Published: October 2020

 IntroductionBoulders, meters-size blocks of rock, are seen in great numbers in high-resolution images of the Moon, Mars, and small bodies. Boulders and their geological associations provide information about surface processes on these bodies. Here we report on rarity of boulders on Mercury, and discuss possible implications of this. Rarity of boulders on MercuryWe studied boulders on Mercury with high-resolution images acquired by MDIS NAC camera onboard MESSENGER. We screened all ~3000 images of the highest resolution (
Volatile release from intrusive magma bodies of terrestrial planets
Authors: Vulpius Sara , Noack Lena , Sohl Frank , Ortenzi Gianluigi , Hoffmann Elis Jörg
Published: October 2020

Besides the accretion from the solar nebular and the degassing from magma oceans, the main source of the atmospheres of terrestrial planets is magmatic volatile release from the interior. The atmosphere on early Earth is crucial for the emergence and evolution of life. It´s build-up and composition is largely influenced by magmatic outgassing. This outgassing process includes the well-studied extrusive as well as the often neglected intrusive volatile release. However, it is assumed that the intrusive magma production rates - at least on Earth - are significantly higher compared to extrusive rates, which makes the investigation and quantification of possible volatile exsolution processes even more important.We simulate the crystallization of an intrusive magma body emplaced at different depths within the lithosphere. As the solubility of volatiles like H2O and CO2 increases with pressure, they usually do not exsolve from the melt. However, through the precipitation of nominally dry minerals, the remaining melt is enriched in incompatible elements and volatiles. They accumulate until a saturation level is reached and the volatiles exsolve. The composition of the resulting volatile phase depends on the solubility of the volatile species, the pressure and temperature, the initial composition of the melt, the partition coefficient and the oxygen fugacity. We consider these parameters in our model and benchmark our results with literature values. Additionally, we investigate the likelihood of reactions with the surrounding mantle, to form water-bearing minerals, during the ascent of volatiles. Finally, we quantify the impact of intrusive degassing on the build-up and composition of the atmosphere.
38175 (2000 EE104) and the Source of Interplanetary Field Enhancements
Authors: Jewitt David
Published: October 2020

We present the first optical observations taken to characterize the near-Earth object 138175 (2000 EE104).  This body is associated with Interplanetary Field Enhancements (IFEs), thought to be caused by interactions between the solar wind magnetic field and solid material trailing in the orbit of the parent body.  Based on optical photometry, the radius (in meters) and mass (in kilograms) of an equal-area sphere are found to be  250(0.1/p)^{1/2} and  1e11(0.1/p)^{3/2}, respectively, where p is the red geometric albedo and density 1500 kg/m3 is assumed.  The measured colors are intermediate between those of C-type (primitive) and S-type (metamorphosed) asteroids but, with correction for the likely effects of phase-reddening, are more consistent with a C-type classification than with S-type. No evidence for co-moving companions larger than 40(0.1/p) meter in radius is found, and no dust particle trail is detected, setting a limit to the trail optical depth < 2e-9.  Consideration of the size distribution  produced by impact pulverization  makes it difficult to generate the  mass of nanodust (minimum 1e5 kg to 1e6 kg) required to account for IFEs, unless the size distribution is unusually steep.  While the new optical data do not definitively refute the hypothesis that boulder pulverization is the source of IFEs, neither do they provide any support for it.Journal: Planetary Science Journal, submitted
Statistics of Saturn Ring Occultations
Authors: Esposito Larry W. , Sremcevic Miodrag , Colwell Joshua E , Eckert Stephanie
Published: October 2020

We calculate the excess variance, excess skewness and excess kurtosis including the effects of cylindrical shadows, along with gaps, ghosts and clumps (all calculated for the granola bar model for rectangular clumps and gaps). The widths and separation of the clumps play an analogous role to the relative size of the particle shadows, δ. Wherever the rings have significant gaps or clumps, those will dominate the statistics over the individual ring particles shadow contribution. In the first model considered, our calculations are based on the moments of the transparency T in that part of the ring sampled by the occultation, thus extending the work of  Showalter and Nicholson (1990) to larger τ and δ, and to higher central moments, without their simplifying assumptions. We also calculate these statistics using an approach based on the autocovariance, autocoskewness and autocokurtosis. This  may be more intuitive, and can be extended to other transparency distributions, e.g., those provided by gaps, ghosts, clumps and granola bars. In a third method, we have refined an overlap correction for multiple shadows, which is important for larger optical depth. This correction is calculated by summing a geometric series, and is similar to the empirical formula, eq. (22) in Colwell et al (2018). These 3 new approaches compare well to the formula for excess variance from Showalter and Nicholson in the region where all are accurate, that is δτ≪1. Skewness for small τ has a different sign for transparent and opaque structures, and can distinguish gaps from clumps. The higher order central moments are more sensitive to the extremes of the size distribution and opacity.As a check, we can explain the upward curvature of the dependence of normalized excess variance for Saturn’s background C ring by the observation of Jerousek etal (2018) that the increased optical depth is directly correlated with effective particle size. For a linear dependence Reff = 12 * (τ – 0.08) + 1.8m from Jerousek’s results, we match both the curvature of normalized excess variance and the skewness in the region between 78,000 and 84,600km from Saturn. This explanation has no free parameters and requires no gaps or ghosts (Baillie etal 2013) in this region of Saturn’s C ring.
The spherical-wavelet techniques for RT simulation and analysis
Authors: Xu Guanglang , Muinonen Karri
Published: October 2020

The spherical wavelet based on the lifting scheme is introduced for adaptive discrete-ordinate sampling of the radiation fields, particularly,  in the radiative transfer computation using iterative schemes. The lifting scheme for wavelet transform is described from an implementation point of view, including the construction of hierarchical geodesic grids on the sphere and wavelet constructions. In addition, we compare the method with the conventional spherical harmonics, numerically investigating the transformation error and efficiency. The transformation matrices are built in the least-squares sense. The results demonstrate the feasibility of using spherical wavelets as an adaptive discrete-ordinate sampling method at the cost of O(N), where N is the number of significant coefficients. 
The fine structure of the subsolar MPB current layer from MAVEN observations: Implications for the Lorentz force
Authors: Boscoboinik Gabriela , Bertucci Cesar , Gomez Daniel , Morales Laura , Mazelle Christian , Regoli Leonardo , Halekas Jasper , Gruesbeck Jacob , Mitchell David , Jakosky Bruce
Published: October 2020

We report on the local structure of the Martian subsolar Magnetic Pileup Boundary (MPB) from minimum variance analysis of the magnetic field measured by the MAVEN spacecraft for six orbits. In particular, we detect a well defined current layer within the MPB’s fine structure andprovide a local estimate of its current density and compare these results with the current density obtained by multi-fluid simulations.This current is of the order of hundreds of nAm-2 which results in a sunward Lorentz force of the order of 10-14 Nm-3. We compare these results with multifluid numerical simulations.This force is associated with the gradient of the magnetic pressure, it accounts for the deflection of the solar wind ions near the MPB and for the acceleration of solar wind electrons which carry the interplanetary magnetic field through the MPB into the MPR. We also find that thethickness of the MPB current layer is of the order of both the upstream (magnetosheath) solar wind proton inertial length and convective gyroradius. The former is consistent with the demagnetization of the ions due to the Hall electric field, an effect observed recently at the Earth magnetopause, while the latter would imply kinetic processes are important at the MPB.This study supports recent results that report the presence of a steady current system around Mars in a similar way to the Earth.
Activities and origins of interstellar comet 2I/Borisov
Authors: Xing Ze-Xi , Bodewits Dennis , Noonan John W. , Feldman Paul D. , Bannister Michele T. , Farnocchia Davide , Harris Walt M. , Li Jian-Yang , Mandt Kathleen E. , Parker Joel Wm.
Published: October 2020

We will present the results of coordinated observations of 2I/Borisov with the Neil Gehrels-Swift observatory (Swift) and Hubble Space Telescope (HST), which allowed us to provide the first glimpse into the ice content and chemical composition of the protoplanetary disk of another star. Comets are condensed samples of the gas, ice and dust that were in a star’s protoplanetary disk during the formation of its planets, and inform our understanding on how chemical compositions and abundances vary with distance from the central star. Their orbital migration distributes volatiles [1], organic material and prebiotic chemicals around their host system [2]. In our Solar System, hundreds of comets have been observed remotely, and a few have been studied up close by space missions [3].  Similarly, interstellar comets offer a glimpse into the building blocks, formation, and evolution of other planetary systems.  However, knowledge of extrasolar comets has been limited to what could be gleaned from distant, unresolved observations of cometary regions around other stars. 2I/Borisov, discovered in Aug. 2019, is the first notably active interstellar comet discovered in our Solar System [4].We used the UltraViolet Optical Telescope (UVOT) of Swift to determine 2I/Borisov’s water production rates and dust content surrounding the nucleus at six epochs spaced before and after perihelion on Dec. 8.55, 2019 UTC (-2.56AU to 2.54AU) [5]. Water production rates increased steadily before perihelion at a rate of increase quicker than that of most dynamically new comets but slower than most Jupiter-family comets. After perihelion, the water production rate decreased much more rapidly than that of all previously observed comets. We used a sublimation model to constrain the active area and minimum radius of the nucleus, and found that a significant fraction of the surface of Borisov is active. We also used Cosmic Origins Spectrograph (COS) on the HST during four epochs around the perihelion and clearly detected the emissions of several bands of the CO Fourth Positive system, which we used to derive CO production rates [6]. Comparing these with the water production rates determined by Swift, we found that after perihelion, the coma of 2I/Borisov contains substantially more CO than H2O gas. Our abundances were more than three times higher than previously measured for any comet in the inner (
Statistical analysis of asteroid taxonomic signatures from magnitude phase function
Authors: Lin Zhong-Yi , Cheng Chung-Chien , Chang Chan-Kao , Tseng Wei-Ling , Ip Wing-Huen
Published: October 2020

According the H-G magnitude system ,this work using the known spectral-type asteroids (about three hundreds asteroids including MBAs and NEAs) found from literature, we derived the new G-value of two main taxonomic groups in both g and r filters (In g filter, C-type is 0.095±0.112, and S-type is 0.257±0.165. In r filter, C-type is 0.091±0.134, and S-type is 0.280±0.158). We then used these values to identify the unknown taxonomic near-Earth asteroids(NEAs) obtained by (ZTF) from June 2018 to May 2020. In total, more than one hundred NEAs had been classified into C- and S-complex. In addition, the investigation of size distribution in NEAs found that the C-complex asteroids are relatively larger than S-complex asteroids, probably due to observational bias (albedo).
A tactile sensor based on magneto-sensitive elastomer to determine the position of an indentation
Authors: Gast Simon , Zimmermann Klaus
Published: October 2020

Abstract. In this paper, we investigate the capabilities of a tactile sensor based on magneto-sensitive elastomers (MSEs). The main feature of the sensor is the determination of the position of indentation. The principle is based on inductance measurements of multiple planar coils and a soft magneto-sensitive layer. The proposed prototype consists of a linear array of hexagonal coils with overlapping sections. First, the results of the experiments are presented, which include a sampling of a sensor region with indentations of constant depth. Subsequently, we introduce a mathematical model based on the bell-shaped flux density distribution of a planar coil. This model consists of ellipse equations with three parameters and a polynomial fit for each parameter. Finally, solving the system of equations results in the determination of the x coordinate of the indentation.
Structural Changes to Maintain a Strong Development Path in Indonesia
Authors: Lewis Christine
Published: October 2020

For many years, Indonesia’s economic growth has been remarkably steady, raising average income by around 4% per year. However, achieving such rates in the medium-to-longer term will likely be more challenging. Using a growth accounting framework and shift-share analysis, this article reviews sources of past growth to highlight opportunities to raise future income growth. The main driver of GDP per capita over the past five decades has been greater use of labor and capital. Structural change in sectoral employment has been a key driver of labor productivity growth. There is scope for productivity growth through further structural change as well as catch-up growth. The role of key policy areas in facilitating this change is considered in light of the middle-income trap literature and policy gaps are assessed in these domains. Policies related to openness, education, rule of law, financial development, and aspects of entrepreneurship all represent opportunities to set Indonesia on a higher growth path.
Protocolo de cirurgia segura: análise da produção e execução em dois hospitais terciários
Authors: Silva Alex Mariano Rosa da , Silva Ivan Tramujas da Costa e , Rocha Gisele dos Santos , Teixeira Elizabeth
Published: October 2020

Objetivo: Analisar o processo de produção e execução do protocolo de cirurgia segura em dois hospitais terciários do município de Manaus.Método: Pesquisa guiada pelo design thinking, com ênfase na técnica do duplo diamante, realizada em dois hospitais públicos no município de Manaus, de julho de 2018 a março de 2019. Foi feita nas etapas: investigativa (observação e questionário) e interventiva (síntese, ideação e entrega). Resultados: Na primeira etapa, com 120 horas de observação, constatou-se que as três fases do protocolo não foram cumpridas; analisando-se as repostas a 63 questionários, reforçou-se a não adesão ao checklist. Com base nesses achados, na etapa de síntese, elegeu-se como foco a aplicação do checklist do protocolo; na etapa de ideação, realizou-se a proposição de solução e a testagem-piloto; a etapa de entrega da solução aos hospitais encerrou o ciclo. Conclusão: A análise do processo de execução do protocolo indicou seu descumprimento, o que sugere o comprometimento da segurança do paciente. A solução testada poderá,após entrega e implementação, contribuir para a execução efetiva do protocolo.