bluuebunny/crossref_metadata_2025 huggingface dataset:
Hubungan Pengetahuan Dan Sikap Calon Pengantin Tentang HIV/AIDS Dengan Pelaksanan Tes HIV
Authors: Harahap Yanna Wari
Published: September 2022

Kasus penderita HIV/AIDS di Indonesia per September 2020 sebanyak 409.857 kasus. Sedangkan di Sumatera utara berjumlah 21.160 orang dan di Kota Padangsidimpuan terdapat 17 kasus HIV/AIDS. Adapun salah satu faktor penyebab tingginya kasus HIV/AIDS adalah disebabkan karena kurangnya pengetahuan masyarakat tentang penyakit HIV/AIDS dan masih tingginya pandangan atau sikap negatif masyarakat tentang HIV/AIDS. Tujuan Penelitian ini adalah untuk mengetahui Hubungan Pengetahuan dan Sikap Calon Pengantin Tentang HIV/AIDS dengan Pelaksanaan Tes HIV di Puskesmas Sadabuan Kota Padangsidimpuan. Jenis penelitian yaitu kuantitatif dengan desain Cross Sectional. Jumlah sampel menggunakan teknik total sampling dengan jumlah 67 responden. Uji statistik yang digunakan adalah Chi Square. Hasil penelitian diketahui ada hubungan Pengetahuan Calon Pengantin tentang HIV/AIDS dengan pelaksanaan tes HIV dengan nilai p (0,017) < α dan ada hubungan sikap calon pengantin tentang HIV/AIDS dengan pelaksanaan tes HIV dengan nilai p (0,021) < α. Diharapkan bagi responden yang memiliki pengetahuan kurang, dapat meningkatkan pengetahuan tentang HIV/AIDS dengan berbagai informasi kesehatan melalui media sosial maupun media cetak.
HUBUNGAN PENGETAHUAN DAN SIKAP WANITA USIA SUBUR TERHADAP MINAT MELAKUKAN IVA TEST DI WILAYAH KERJA PUSKESMAS WEK I KOTA PADANGSIDIMPUAN TAHUN 2020
Authors: Sari Helmy , Aswan Yulinda , Pohan Sakinah Yusro
Published: September 2022

Angka kematian akibat kanker serviks di Indonesia disebabkan karena 95% wanita usia subur (WUS) tidak menjalani pemeriksaan secara dini sehingga menyebabkan keterlambatan diagnosis dari kanker serviks dan menurunkan harapan hidup wanita. Tingginya kasus kanker serviks disebabkan oleh kurangnya pengetahuan dan juga kesadaran untuk melakukan deteksi dini seperti pemeriksaan IVA (Inspeksi Visual Asam Asetat) sehingga kanker serviks baru ditemukan pada stadium lanjut. Tujuan dari penelitian ini adalah untuk mengetahui hubungan pengetahuan dan sikap terhadap minat melakukan IVA test di Puskesmas Wek I Kota Padangsidimpuan Tahun 2020. Jenis Penelitian ini adalah penelitian kuantitatif dengan pendekatan cross sectional study. Populasi dalam penelitian ini adalah seluruh wanita usia subur (30 – 50) tahun yang tinggal di wilayah kerja Puskesmas Wek I yaitu sebanyak 4146 WUS. Teknik pengambilan sampel menggunakan teknik simple random sampling dengan jumlah sampel 97 WUS di wilayah kerja Puskesmas Wek I. Pengumpulan data dilakukan menggunakan kuesioner. Hasil penelitian menunjukkan bahwa terdapat 64 responden (95,5%) dengan pengetahuan kurang dan tidak melakukan IVA test (p value = 0,000), serta 62 responden (93,9%) dengan sikap negatif dan tidak melakukan IVA test, p value = 0,000 (p < 0,05). Kesimpulan diperoleh bahwa terdapat hubungan antara pengetahuan dan sikap wanita usia subur terhadap minat melakukan IVA test. Diharapkan penelitian ini dapat meningkatkan minat melakukan IVA pada WUS yang sebelumnya rendah menjadi tinggi, misalnya dengan memberikan sosialisasi tentang pentingnya pemeriksaan IVA.
Observing the very early stages of the formation of a circumbinary planetary system in SVS 13
Authors: Anglada Guillem , Diaz-Rodriguez Ana K. , Blázquez-Calero Guillermo , Osorio Mayra , Gómez José F. , Fuller Gary A. , Estalella Robert , Torrelles José M. , Cabrit Sylvie , Rodríguez Luis F. , Macías Enrique , Carrasco-González Carlos , Zapata Luis A. , de Gregorio-Monsalvo Itziar , Ho Paul T. P.
Published: September 2022

The early stages of the formation of binary stellar systems are still rather poorly understood observationally, which contrasts with some significant recent improvements in numerical simulations. We present a comprehensive study with the VLA and ALMA of the close (separation = 90 au) proto-binary system SVS 13. Our very high sensitivity and spatial resolution observations trace the dust as well as the ionized and molecular gas in this system, reaching scales as small as ~10 au. We infer the orbital motion and masses of the two protostars. We image two circumstellar disks and a still-forming circumbinary disk with prominent spiral arms extending ~500 au. We study the 3D kinematics of the system and measure the physical properties of the disks. We also find evidence for variation of chemical properties on scales of a few tens of au. Finally, we will discuss on how the properties of the SVS 13 system compare with those of a few other protobinary systems that have been observed with a similar degree of detail, and with the predictions of numerical simulations. This kind of information provides some clues on the final configuration of planetary systems in binary systems.

<img src="https://contentmanager.copernicus.org/fileStorageProxy.php?f=gnp.c8ee04a7c48268209682561/sdaolpUECMynit/2202CSPE&app=m&a=0&c=27e8eacc3cd75b4b612009405aa39837&ct=x&pn=gnp.elif&d=1" alt="" width="702" height="670">

ALMA observation of dust in the disks around SVS 13 (credit: A.K. Diaz-Rodriguez, G. Anglada 2022).

<img src="https://contentmanager.copernicus.org/fileStorageProxy.php?f=gnp.5b320fc7c48261709682561/sdaolpUECMynit/2202CSPE&app=m&a=0&c=a0388163eaebf96cf38bbbbd829d450d&ct=x&pn=gnp.elif&d=1" alt="" width="698" height="676">

 

Cartoon model of the system. The red-blue colours indicate the motion of the gas. Red – away from us, blue – towards us. The peculiar yin-yang shape results from the combination of infalling and rotation motions (credit: A. K. Diaz-Rodriguez et al. 2022).
Modification of icy planetesimal interiors by early thermal evolution and collisions
Authors: Golabek Gregor , Jutzi Martin
Published: September 2022

In the early solar system radiogenic heating by 26Al and collisions are the two prominent ways expected to modify the internal composition of icy planetesimals, building blocks of comets, by removing highly volatile compounds like CO, CO2 and NH3. However, observations indicate that
even large comets like Hale-Bopp (R ≈ 35 km) can be rich in these highly volatile compounds [1].
Here we constrain under which conditions icy planetesimals experiencing both internal heating and collisions can retain pristine interiors [2]. For this purpose, we employ both the state-of-theart finite difference marker-in-cell code I2ELVIS [3] to model the thermal evolution in 2D infinite
cylinder geometry and a 3D SPH code [4] to study the interior heating caused by collisions among icy planetesimals. For simplicity we assume circular porous icy planetesimals with a low density (≈ 470 kg/m3) based on measurements for comet 67P/Churyumov-Gerasimenko [5].
For the parameter study of the thermal history we vary (i) icy planetesimal radii, (ii) formation time and the (iii) the silicate/ice ratio. For the latter we keep the mean density fixed and change the porosity of the icy planetesimal. For the impact models we use porous, low-strength objects and
vary (i) target and (ii) projectile radii, (iii) impact velocity as well as (iv) impact angle. Potential losses of volatile compounds from their interiors are calculated based on their critical temperatures taken from literature [6]. Our combined results indicate that only small or late-formed icy planetesimals remain mostly pristine, while early formed objects can even reach temperatures high enough to melt the water ice. These results have strong implications for the formation time and initial size of comets, Kuiper belt objects and active asteroids.

REFERENCES
[1] Morbidelli & Nesvorný, In: The Trans-Neptunian Solar System. 25–59 (2019). [2] Golabek & Jutzi, Icarus 363, 114437 (2021). [3] Gerya & Yuen, Phys. Earth Planet. Int. 163, 83-105 (2007). [4] Jutzi, Planet. Space Sci. 107, 3–9 (2015). [5] Sierks et al., Science 347, 1044 (2015). [6] Davidsson et al., Astron. Astrophys. 592, A63 (2016).
Thermal-orbital evolution of a librating Enceladus
Authors: Beuthe Mikael , Rivoldini Attilio , Baland Rose-Marie , Van Hoolst Tim
Published: September 2022

Since being first visited by the spacecraft Cassini in 2005, the Saturnian moon Enceladus has attracted far more attention than could be guessed from its modest size and lack of atmosphere, compared to its giant neighbour Titan. The reason for this state of affairs is the surprising geophysical activity observed at Enceladus’s south pole: a large thermal anomaly crossed by parallel faults ejecting huge plumes of water vapour and icy particles. From the start, it has been suspected that this anomalous activity results from solid tides caused by the eccentricity of the orbit, although the localisation of the heat source remains a puzzle. The simplest explanation consists in dissipating energy either within the icy shell or in the subsurface ocean, but it fails by more than one order of magnitude to match the measured power or to account for the 20 km-thickness of the icy shell. Dissipation within the core could provide enough power if the core is very soft, but this assumption is hardly consistent with laboratory measurements of material properties.

Alternatively, power could be episodically released if the orbit undergoes periodic variations. Enceladus and the neighbouring moon Dione are currently in a 2:1 mean motion resonance. This mechanism protects their orbital eccentricities against damping due to dissipation within the satellites, while it does not forbid periodic variations of the eccentricity around a long-term equilibrium value. Coupling orbital evolution to dissipative eccentricity tides is however not sufficient to induce significant variations of the orbit and thermal output. Besides eccentricity tides, libration is another cause of viscoelastic deformations. Although libration now contributes little to Enceladus’s energy budget, its amplitude is enhanced by a free libration mode as the icy shell decreases in thickness, and could thus become the major contributor to dissipation if the shell is thin enough. We report here the results of a thermal-orbital evolution model including eccentricity tides and libration of a viscoelastic icy shell above a subsurface ocean.
Deriving mixing ratios of heavier neutral species in Saturn's ionosphere from light ion measurements
Authors: Dreyer Joshua , Vigren Erik
Published: September 2022

Helium ions, He+, react only slowly with molecular hydrogen. A consequence of this is that He+ ions produced by, for example, photoionization of He in H2-dominated ionospheres, such as those of Jupiter and Saturn, can have principal loss mechanisms other than through reactions with molecular hydrogen even if the other reactants prevail in rather small volume mixing ratios. The Ion and Neutral Mass Spectrometer (INMS) onboard the Cassini mission operated in open-source ion mode during a few of the passages through Saturn’s upper atmosphere throughout the proximal orbits in 2017. Due to the high spacecraft velocity, exceeding 30 km/s, the retrieval of ion number densities was limited to light ion species with masses (for singly charged species) of < 8 Da. The retrieval of number densities of volatiles like H2O, CH4, NH3, N2 and CO were in part complicated by adsorption effects.

We seek to make an independent estimate of the mixing ratios of volatiles other than H2 and He by making use of a simple model focusing on the production and loss balance of helium ions. We first consider two models to estimate the local production rate of He+ from the measured density profiles of He and H2 and show that these give estimates in reasonable agreement with each other. Then we show that the calculated concentration of He+ exceeds the observed values by up to two orders of magnitude if we only account for the loss of He+ ions through reactions with molecular hydrogen. We take this as a strong indicator that the principal loss mechanism of He+ in Saturn’s ionosphere is through reactions with other species than H2. We proceed with a brief survey of chemical reaction databases highlighting that it seems reasonable to consider an effective rate constant of k1 ≈ (1.0 ± 0.5)*10-9 cm3 s-1 for reactions involving the neutralization of He+ in reactions with H2O, CH4, NH3, N2 and CO. This allows us to estimate the mixing ratio of these molecules across an altitude profile. Our results are compatible with the average values reported by Miller et al. (2020) and show indications of enhanced mixing ratios towards lower altitudes and/or near equatorial latitudes.
A photometric study of the Enormous Cloud Cover seen in theVenus' night-side disk
Authors: Satoh Takehiko , Sato Takao , Horinouchi Takeshi , Imamura Takeshi , Hashimoto George
Published: September 2022

The 2-µm infrared camera (IR2) onboard Akatsuki observed a remarkable cloud feature in the Venus' night-side disk, a sharp discontinuity of cloud opacity which subtends latitudinally to some thousands of km (Peralta et al., 2020).  Though obvious and seemingly common in the Venus' atmosphere as similar features can be identified in imagery since the beginning of the night-side observations (Allen and Crawford, 1984), the mechanism of this emormous cloud cover (ECC) has not yet been explained.

To characterize this ECC (aerosol size parameters and column numbers), we have analyzed the Akatsuki/IR2 data, as well as the Venus Express/VIRTIS-M data. Six sets of the Akatsuki/IR2 data (MM-DD = 03-27, 07-22, 08-09, 08-18, 08-27, and 09-06) are measurable with varying photometric uncertainties, due to contaminations from the intense day crescent. Seven VEx/VIRTIS data, as tabulated in Peralta et al. (2020), are also measured by the consistent method with that for IR2 data.
A reference region, which is just west of the discontinuity and is seemingly not affected by the ECC, is defined as the background cloud (BC) region. Radiances at the BC and the ECC regions are measured for two IR2 filter passbands (1.735 and 2.26 µm). They are plotted in the correlation plot (radiance at 2.26 µm in horizontal axis and radiance at 1.735 µm in vertical axis). The BC-to-ECC slope can be used to infer the aerosol size and abundance that changes the BC region to the ECC region.

Comparison of obtained characteristics of the ECC for different observing times will be presented and implication to the possible mechanism of this large-scale phenomenon will be discussed.
Examples for planet-to-star interactions
Authors: Szabó Gyula
Published: September 2022

Planet-star interactions are considered to have a Janus-faced character. Most of the known forms belong to star-to-planet interactions, for which well-known examples are the stellar irradiation, rotation and stellar activity affecting the planet. We can only rarely see planet-to-star scenarios, mostly because of the smaller planets can less affect the stellar physics. In this talk, we review three examples for such scenarios, including commensurabilities between the stellar spin and the planetary orbit, excitation of stellar activity, and stellar oscillations suffering planetary perturbations. The observational basis of our examples, Kepler-13A, AU Mic and WASP-33 also cover the three major exoplanet missions: Kepler, CHEOPS and TESS, nicely showing how the space-based exoplanet photometry started revealing the (almost) hidden face of Janus.
Heat transfer in the ocean of Enceladus: connecting unconsolidated core and surface ice shell 
Authors: Bouffard Mathieu , Choblet Gaël , Tobie Gabriel , Amit Hagay , Čadek Ondřej , Terra-Nova Filipe
Published: September 2022

Observations from the Cassini spacecraft imply the presence of a global salty ocean underneath Enceladus’ ice shell, with ongoing hydrothermal activity at its seafloor. Previous numerical simulations showed that convection in Enceladus’ unconsolidated core generates enough dissipation to sustain the ocean and produces a strongly heterogeneous heat flow pattern at the seafloor that looks promising for explaining the surface ice topography. Yet, how the ocean in-between connects the deeper core to the surface ice shell is unknown. The dynamics of the ocean is thus the missing piece of the Enceladus puzzle towards a fully self-consistent model of the heat transfer in this moon. We fill this gap by performing 3D numerical simulations of the buried ocean of Enceladus. We show that, for the strongly heterogeneous heat flow pattern expected at the seafloor from the unconsolidated core model, azimuthal deflection of strongly localised plumes by the Coriolis force inhibits the heat transfer at low latitudes. The resulting heat flow pattern at the ocean/ice interface is qualitatively consistent with the surface ice topography and in decent quantitative agreement with an ice shell model derived from observations. Using passively advected tracers particles, we predict rising times for hydrothermal products of the order of 1-2 months, in line with previous observations-based predictions. We are thus now able to draw a complete self-consistent model of the heat transfer in Enceladus, explaining the global characteristics of this moon: global ocean, strong dissipation, reduced ice-shell thickness at the south pole and seafloor activity.
Scientific performances evaluation of the Raman Laser (RLS) FM-instrument for Exomars mission to Mars
Authors: Rull Fernando , Moral Andoni , Lopez-Reyes Guillermo , Perez Carlos , Seoane Laura , Zafra Jesus , Veneranda Marco , Manrique Jose Antonio , Rodriguez Eduardo , Rodriguez Pablo , Belenguer Tomás , Prieto Olga
Published: September 2022

The Raman Laser Spectrometer (RLS) is part of the analytical payload located inside Rosalind Franklin rover for the Exomars Mission to Mars.

The RLS instrument consists of three main units: 1) the optical head that focus the laser excitation on the sample and collect the scattered light from the same area (with a 50 microns spot); 2) the spectrometer analyzing the Raman signal in the spectral range 150-3800 cm-1 with an average spectral resolution of 8 cm-1 and 3) an electronic control unit in which the laser is included.  These units are connected by optical fibers and electrical hardness. The instrument will investigate powdered samples collected by the rover at the surface and subsurface of Mars at the mineral grain scale. (1)

The RLS development stages comprised the development, verification, test and evaluation of the scientific performances of two main models: Engineering Qualification Model (EQM) and Flight Model (FM). 

Because the consecutive delays in Exomars launch to Mars an important aspect related with this situation is the evaluation of the scientific performances with time of these models comparing the results obtained at the pre-delivery stage with those obtained at the rover analytical laboratory drawer (ALD) and rover integrated stages.

Additionally it is also of great interest evaluate the scientific results obtained in the framework of dedicated science activities currently ongoing at the ALD and rover levels  in which the evaluation of the combined science potential among the three instruments inside Rosalind Franklin rover (MicrOmega, RLS and MOMA) is outstanding.

In the present work interest is devoted to the scientific performances evaluation of the RLS-FM at the different levels: pre-delivery, rover analytical drawer (ALD) and finally integrated on the Rosalind Franklin rover.

For that, observation of the data obtained on the calibration target (CT) is mainly used although data obtained on standard and natural samples at the pre-delivery stage are also presented and discussed.

Instrument response as function of temperature, atmospheric pressure conditions and changes on the main acquisition parameters was evaluated. Estimation of the different band parameters observed (band position, intensity, bandwidth and SNR) allowed performances comparison along the different phases of the process and comparison with the established scientific requirements.

References:

Rull, S. Maurice, I. Hutchinson, A. Moral et al., Astrobiology, 2017, 17, 627-654.
Photometry and model of near-Earth asteroid 2022 AB from one apparition
Authors: Kwiatkowski Tomasz , Koleńczuk Paweł , Mykhailova Sofiia , Kamińska Monika , Kamiński Krzysztof , Troianskyi Volodymyr , Kryszczyńska Agnieszka , Oszkiewicz Dagmara , Wilawer Emil
Published: September 2022

This presentation will show results of the observing campaign for the very small, super-fast rotating NEA, 2022 AB. It is a follow-up of our previous work on another similar object, 2021 DW1 (Kwiatkowski et al. 2021). The main objective of this project is to use lightcurves observed during one apparition along the long arc in the sky to derive NEA spin axes. They are then used to compute object obliquities to test the end states of the YORP evolution, which according to some theories should be close to 0 or 180 deg.

After the discovery of 2022 AB on 2 January 2022 it became known that it would be observable from many different viewing/illumination geometries while maintaining a decent magnitude V<19 mag. The absolute magnitude of 2022 AB, H=23.6 (reported by the MPC) suggested that it could be a super-fast rotating asteroid (rotation period P<2.1 hours), with a diameter D<150~m. The small size of this object means that its rotation can be strongly influenced by YORP.

We observed 2022 AB photometrically from 4 Jan to 26 Jan, from 27 locations around the world, from Australia, through South Korea, Europe, the United States, to Hawaii. The telescope sizes ranged from 0.28-m to 10.0-m. During that time we collected 89 lightcurves exposed through different filters. The analysis of such rich data sets is time consuming and, until now, we only have some partial results. The object has a synodical period of rotation of 182 seconds, and most likely belongs to the Cb taxonomic class (see a poster by Koleńczuk et al. at this conference for details).

At the conference, we will present full physical characterisation of 2022 AB, including its spin axis, shape, mag-phase curve, taxonomy, and size. We will discuss the obliquity of its rotation axis in the context of YORP evolution.

Acknowledgements

PK acknowledges support from the National Science Centre, Poland, Grant No. 2021/41/N/ST9/04259.

References

T. Kwiatkowski, P. Koleńczuk, A. Kryszczyńska, D. Oszkiewicz, K. Kamiński, M. K. Kamińska, V. Troianskyi, B. Skiff, N. Moskowitz, V. Kashuba, M.-J. Kim, T. Kim, S. Mottola, T. Santana-Ros, T. Kluwak, L. Buzzi, P. Bacci, P. Birtwhistle, R. Miles, and J. Chatelain (2021), Photometry and model of near-Earth asteroid 2021 DW1 from one apparition, A&A 656, A126

 
Modelling the interplay between protoplanetary disks, planets and X-ray photoevaporative winds: Observational diagnostics
Authors: Weber Michael , Ercolano Barbara , Picogna Giovanni
Published: September 2022

Disk winds and planet-disk interactions are considered to be two of the most important mechanisms that drive the evolution and dispersal of protoplanetary disks and in turn define the environment in which planets form and evolve. While both have been studied extensively in the past, we combine them into one model by performing three-dimensional radiation-hydrodynamic simulations of planet-hosting disks that are undergoing X-ray photoevaporation, with the goal to analyse the interactions between both mechanisms and to produce synthetic observations of common disk and wind diagnostics that could serve as observational tools for testing the interactions between the planet, the disk and the wind in our models.

The models show that a cavity in the gas disk that is carved by a sufficiently massive planet can significantly affect the structure and kinematics of a photoevaporative wind. This effect can be strong enough to be observable in commonly observed wind diagnostic lines, such as the [OI] 6300 Å or [SII] 6730 Å line, which we model with detailed photoionization calculations. When the disk is observed at inclinations around 40° and higher, the synthetic spectral line profiles may exhibit a peak in the redshifted part of the spectrum, which cannot easily be explained by simple wind models alone. Moreover, massive planets can induce asymmetric substructures within the disk and the photoevaporative wind, giving rise to temporal variations of the line profiles that can be strong enough to be observable on timescales of less than a quarter of the planet's orbital period.

 
Machine learning methods applied to meteor detection filtering
Authors: Anghel Simon , Nedelcu Dan-Alin , Birlan Mirel , Boaca Ioana
Published: September 2022

Introduction: Recent expansions in fireball networks has lead to an increase in the number of events recorded each night. Due to the mechanism at the source of the detection procedure (i.e. tracking sources of light), the majority of the events is comprised of false meteors. These make their way in trajectory computations, and lead to erroneous orbits [e.g. 1].

Aims: For this study we explore several machine learning (ML) models for their ability to filter the false detections.

Methods: First, a supervised validation was employed on the meteor detections obtained by stations within the Meteorites Orbits Reconstruction by Optical Imaging (MOROI) network [1, 2], between 2017-2020.  Next, a set of ML models suited for classification were applied to a selection of features computed from the data. Finally, each model was tuned to their optimal hyper-parameter value, to obtain the highest score.

Results: The Neural networks method was found to best filter out the false meteors, with a recall score of 96%, followed by 95% for Gradient Boost and Random Forest algorithms. The score is expected to increase when employing a spatio-temporal filter and pixel brightness information. The results entail follow-up studies on the currently expanding FRIPON network [4].

References: [1] Gural et al. (2020) Planetary and Space Science 182, 104847. [2] Nedelcu D. A. et al. (2018) Romanian Astronomical Journal 28, 1, 3-11. [3] Anghel S. et al. (2021) in LPI Contributions 84, Abstract #6027. [3] Colas F. et al. (2020) Astronomy & Astrophysics 644:A53.
Unusual polarimetric properties for interstellar comet 2I/Borisov
Authors: Bagnulo Stefano , Cellino Alberto , Kolokolova Ludmilla , Nežič Rok , Santana-Ros Toni , Borisov Galin , Christou Apostolos , Bendjoya Philippe , Devogèle Maxime
Published: September 2022

Introduction

Only two interstellar objects have been observed passing through our Solar System to date. The first one, 1I/‘Oumuamua, discovered in 2017 in its post-perihelion phase, showed mostly asteroidal characteristics with some potential evidence of comet-like behaviour, but 2I/Borisov has showed clear evidence of comet activity since its discovery in 2019, prior to its perihelion passage in December of that year. This made it the first confirmed interstellar comet, so naturally many different observations were conducted by astronomers around the world to learn more about the peculiar object.

Methodology

In this work we present the analysis of polarimetric observations of the interstellar comet 2I/Borisov conducted with the FORS2 instrument located on the European Southern Observatory's Very Large Telescope Unit 1 (Antu). A series of polarimetric observations was performed between December 2019 and March 2020 using three different broadband filters in the visible regime in order to ascertain the physical characteristics of the coma dust particles.

Results & Conclusions

We find that polarisation of 2I/Borisov is higher than is usually measured for Solar System comets. This distinguishes the interstellar comet from all dynamically evolved comets in our Solar System. This evidence of 2I/Borisov being more pristine than the observed Solar System comets is corroborated by the fact that the comet with the closest polarimetric properties is C/1995 O1 (Hale–Bopp), which is believed to have approached the Sun only once before its apparition in 1997. Furthermore, and unlike both Hale–Bopp and many other comets, interstellar comet 2I/Borisov shows a polarimetrically homogeneous coma, unchanging with cometocentric distance, again suggesting it is even more pristine than the observed comets from our own Solar System. It is thus likely that it has never passed very close to its native star.
Protoplanetary disk mass loss near O- and B-type stars: an empirical view
Authors: van Terwisga Sierk , Hacar Alvaro
Published: September 2022

The ability of protoplanetary disks to form planets depends on the evolution of their bulk (dust) mass reservoir. Surveys of nearby star-forming regions have revealed that there is a time dependence on the disk dust mass. In different regions in the Orion molecular clouds, meanwhile, the photoevaporation of disk material by nearby young O-type stars is clearly visible. However, the evolution of disk masses as a function of the FUV radiation field is not usually studied empirically, and its influence around fainter, but more common, B-type stars is not well constrained by observations.

In this contribution we take an empirical view of the impact of external FUV fields on the evolution of protoplanetary disks in Orion, by using existing surveys in the Trapezium and NGC 2024 clusters, and the new N = 873 Survey of Orion Disks with ALMA in L1641 and L1647. Together, these observations allow us to confront model predictions, and provide a constraint on how commonly external photoevaporation determines the evolution of planet-forming material in the first megayears.
Condensation path of the protolunar disk and the Earth's first atmosphere
Authors: Caracas Razvan
Published: September 2022

Catastrophic events dominated the history of the early; the last Giant Impact was energetic enough to transform the proto-Earth and the impactor Theia into a protolonar disk or synestia. The Earth – Moon couple condensed upon cooling from this object. The first stage of the Earth condensation was into fully molten Magma Ocean.

Here we consider a six-component silicate melt whose composition reproduces dry pyrolite [1], the chemical and mineralogical model for the bulk silicate Earth (BSE). We explore the melts at the atomic scale, using ab initio molecular dynamics simulations. We monitor the behavior of a series of volatiles, like H2O, CO, and CO2, in the temperature and density ranges characteristic to the magma ocean.

We find that carbon is massively released in the first outgassing stage, mostly as CO2. The gas, with a strong greenhouse effect, contributed to maintaining a hot dense atmosphere through a long geological time. As such, water degassed only at a later stage, when the pressure and the temperature dropped significantly. The relative proportion of released CO2 increased with increasing oxidation state, decreasing density, and decreasing temperature [2].

The carbon fraction that remained in the melt formed oxo-carbon species in the upper parts of the magma ocean. In the deeper parts, carbon formed complex polymerized species, involving both Fe and Si [3].

Thus, our simulations offer a remarkable atomistic view in the mechanisms of magma outgassing and reactions with atmospheric gases. Our results can have extensive implications not only in understanding the chemistry of the atmosphere from the early Earth, but also in understanding volcano degassing and eruptions today.

 

This work was supported by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement number 681818 IMPACT), by the Extreme Physics and Chemistry Directorate of the Deep Carbon Observatory, by the Research Council of Norway project HIDDEN, and through its Centres of Excellence funding scheme, project number 223272.

 

[1] McDonough & Sun (1995) Chemical Geology 120, 223-253.

[3] Solomatova & R. Caracas (2021) Science Advances 7, eabj0406.

[2] Solomatova & R. Caracas (2019) Nature Communications 10, 1-7.

 

 
Observational Facilities and Stellar Characterization Capabilities at Tartu Observatory
Authors: Ramler Heleri , Kama Mihkel , Folsom Colin , Aret Anna , Eenmäe Tõnis
Published: September 2022

Tartu Observatory telescopes offer unique guaranteed access to objects in the Northern hemisphere. The observational facilities include a 1.5- m and 0.6-m classic Cassegrain reflectors, and 0.31-m remotely controllable telescope .

 The 1.5 m telescope is currently equipped with a long-slit Cassegrain spectrograph used for stellar characterisation. Historically, the objects of interest have been massive stars but we are now developing new research direction and expanding the list of targets to exoplanet- and disk-hosting stars.

We have started evaluating our capabilities to characterise host stars spectroscopically to determine their parameters and composition. In 2020, we carried out a pilot study of a TESS candidate planet host, which we found to have a rare, strong chemical peculiarity [1]. This also allowed us to prepare our tools, workflow, and end-to-end analysis. We are also contributing to the European Space Agency Ariel space mission by offering stellar activity monitoring.

The 0.6-m and 0.31-m telescopes are utilised for photometric measurements and the 0.31-m one in particular has been a workhorse for exoplanet transit monitoring. Since 2020, we have made significant preparations to develop and prove our transit observation capabilities: we have observed more than 70 transit light curves. About  half of them have been submitted to ExoClock to contribute to Ariel mission planning.

Concerning future upgrades, Tartu Observatory will have new instruments by the middle of 2023. The upgrades include procuring a medium resolution echelle spectrograph (projected bandwidth 390 nm to  750 nm, R= 25 000) and new photometer (Johnson-Cousins BVRI and SDSS filters) for the 1.5-m telescope, which will not only enhance our capabilities in both spectroscopic and photometric data retrieval of host stars. In addition, a new remote control system of the telescope will be installed and improvements on instrumentation for the 0.6-m and 0.31-m photometric telescopes will be made. 

This presentation will give an overview of our facilities, and of current and future spectroscopic and photometric capabilities.

 

References:

“A rare phosphorus-rich star in an eclipsing binary from TESS”, Colin P. et al., A&A 658 A105 (2022), DOI: 10.1051/0004-6361/202142124
Looking for biosignatures in a pristine Mars analogue environment on Earth
Authors: Palma Vera , Jiménez-Morillo Nicasio T. , Sauro Francesco , Massironi Matteo , De la Rosa José M. , González-Pérez José A. , Onac Bodgan P. , Tiago Igor , Caldeira Ana Teresa , Miller Ana Z.
Published: September 2022

The Selvagens Islands (Madeira, Portugal), located in the North Atlantic, are a small archipelago of volcanic origin formed by two main islands, which emerged in the Oligocene (25-29 Ma). These oceanic islands, designated Nature Reserve in 1971, are recognized as a unique example of extremely valuable marine and terrestrial biodiversity, characterized by many endemic species. Still unblemished by civilization, this isolated and undisturbed ecosystem makes the volcanic caves from Selvagens a promising model system for investigating biosignatures preserved in the rock record that could be valuable for astrobiology. Understanding these never explored subterranean environments may not only provide insights into the early life on Earth, but also into microbially-mediated mechanisms with profound implications for geomicrobiology.

During the scientific expedition to the Selvagens Islands held in the framework of the MICROCENO research project, geological and speleological surveys were conducted for the first time on the Selvagem Grande Island to understand cave genesis and for a detailed comparison between terrestrial caves and similar features observed on the Moon and Mars.

The Inferno Cave, one of the three main terrestrial caves of the Selvagens, with 135 m in length, has unique secondary mineral deposits, noticeable by the copious amounts of a fine white powder or snow-like crusts scattered throughout the cave (on floor and walls). In this study, we have conducted a multidisciplinary characterization of the gypsum deposits based on samples collected in the Inferno Cave, with the aim to recognize biosignatures and reconstruct paleoenvironmental changes preserved in the gypsum sequence of the pristine Selvagens Islands.

From the mineralogical point of view, the whitish powdery deposits found on the cave walls and floor are mainly composed of gypsum and minor amounts of clay minerals.

Thermal analyses (TG/DTG-DsC) revealed the presence of labile and stable (decomposed between 200 and 400 ºC and 400 and 650 ºC, respectively) organic matter (OM), with contrasting relative abundances among the gypsum samples.

The stable isotope composition of carbon was determined by elemental analysis coupled to isotope ratio mass spectrometry (EA/IRMS) to decipher the origin of the organic fraction preserved in the gypsum deposits. Two well-differentiated organic matter pools were distinguished: one comprising
ExoAtmospheres: a community database for exoplanet atmospheres research
Authors: Palle Enric
Published: September 2022

The stud of exoplanet atmospheres is an exciting and vibrant field of research, where new discoveries and publications occur at a very fast pace and it is easy to miss many interesting results. The main purpose of the Exoplanet Atmospheres Database is to become a quick and useful repository of all available exoplanet atmospheres publications, and also to help in the gathering of useful references for a given planet or plane types.
TOI-270 as a unique testbed for exoplanet formation & evolution
Authors: Günther Maximilian N.
Published: September 2022

The nearby TOI-270 system provides an unparalleled opportunity to observationally probe hypotheses for exoplanet formation and evolution. The system hosts one super-Earth and two sub-Neptunes near mean-motion resonances and transiting a bright (K-mag 8.25) M3V dwarf. Strangely, M-dwarf systems harbouring only super-Earths or only sub-Neptunes are ubiquitous. However, for still unknown reasons, systems with multiple planets spanning the radius valley are rare - and we know merely a handful of systems bright enough for precise mass measurements and atmospheric studies. To this end, TOI-270's planets are exceptionally favourable for detailed transit timing variation (TTV) and transmission spectroscopy observations. First, with the planets orbiting near low-order resonances (5:3 and 2:1), our extensive observing campaign with eight different observatories since 2018 yields clear TTV signals for planets c and d, with amplitudes of around 10 min and a super-period of circa 3 yr. Using dynamical models, we can thus significantly constrain their radii, mass ratios, and eccentricities. This adds to complementary radial velocity (RV) mass measurements from HARPS and ESPRESSO. Second, via HST and JWST transmission spectroscopy we can characterise and compare the atmospheres of two sub-Neptunes formed from the same protoplanetary nebula and test hypotheses like photoevaporation, core-powered mass-loss, and gas-poor formation. As one of the best-constrained small planet systems, TOI-270 can thus serve as a unique observational testbed for formation and evolution theories. 
Venturing into Space Science, a case of Zambia
Authors: Simpemba Prospery C. , Ng'andu Alvert , Sibanda Patrick , Banda Faustin , Nambala Fred Joe
Published: September 2022

The peaceful uses of outer space has, since many years back, provided a powerful tool for furthering the well-being of humanity and the earth’s environment.  Modern space applications are fundamental tools for achieving the United Nations Global Sustainable Development Goals. It is therefore justifiable that a land-linked country Zambia should, as a matter of principle, begin to put resources together to develop her capabilities in space science and technology, build capacity and apply the technology for social and economic development of her people. In this paper we discuss the steps taken by the Zambian Government to roll out a space programme. On parallel sides, public universities, namely the University of Zambia, the Copperbelt University, Kwame Nkrumah University and Mulungushi University have started developing study programmes that will produce the required human resource for this robust programme.
Juno magnetometer observations constrain Jupiter’s dynamo, interior state, deep zonal flow, and planetary rotation rate. 
Authors: Connerney Jack , Timmins Sidey , Jorgensen John , Kotsiaros Stavros , Jorgensen Peter , Merayo Jose , Herceg Matija , Bloxham Jeremy , Moore Kimberly , Bolton Scott , Levin Steven
Published: September 2022

The Juno spacecraft, in orbit about Jupiter since 2016, continues to map Jupiter’s magnetic field with ever increasing resolution in space and time. The “JRM33” spherical harmonic model of the field, based on the first 32 orbits of the Prime Mission, is well fit by a Lowes' spectrum with a dynamo core radius of 0.807 +/- 0.006 Rj, identified with the outer radius of the convective metallic hydrogen region that exists beneath a layer stably stratified by the precipitation of “helium rain”. Observations near the equatorial magnetic anomaly known as the Great Blue Spot (GBS) are consistent with the (few cm/s) eastward drift of the GBS and provide evidence of advection of the magnetic field by deep (few 1000 km) zonal winds. Magnetic field observations during Juno’s 6 years in orbit, as well as those acquired in past decades by Voyager and Ulysses spacecrafts, evidence a secular westward drift of the main dipole in longitude (of 0.11 degrees/yr from Juno observations, 0.09 degrees/year estimated from earlier flybys) suggesting a more accurate rotation period for the deep interior
Discovering the Surface Composition of TNOs (DiSCo-TNOs) with the James Webb Space Telescope
Authors: De Pra Mario , Pinilla-Alonso Noemi , Souza Feliciano Ana Carolina , Schambeau Charles , Harvison Brittany , Emery Josh , Cruikshank Dale , Pendleton Yvonne , Holler Bryan , Stansberry John , Lorenzi Vania , Muller Thomas , Guilbert-Lepoutre Aurélie , Peixinho Nuno , Bannister Michele , Brunetto Rosario
Published: September 2022

The discovery of trans-Neptunian objects (TNOs) marked an important milestone in the understanding of the outer Solar System. Due to their environmental conditions, these objects could preserve the most pristine materials that were present on the protoplanetary disk. Studies focused on understanding TNOs physical and dynamical properties can be used to probe planetary formation processes and the subsequent solar system dynamical evolution that followed the formation era.

Nowadays, above 3,000 TNOs have been detected, including four large ones that receive the official designation of dwarf-planets. Analysis of TNOs revealed a compositionally and dynamically diverse population. However, despite all the progress in the last decades, much is still unknown about the composition of the TNOs.

The recently launched James Webb Space Telescope (launched on December 25, 2021) will provide a powerful tool to investigate the TNOs surface composition, where all prior instrumentation has fallen short. The NIRSpec instrument onboard JWST will provide high-quality data that will surpass the quality of the data available by orders of magnitude. DiSCo-TNOs, lead by the Florida Space Institute, is the only large program approved by JWST for the study of the Solar System. With it, we aim to assess the relative ratio of water ice, complex organics, silicates, and volatiles on the surface of a large sample of TNOs. This information is vital to improving models of the formation of our Solar System and other planetary systems. In this talk we present the scope of the DiSCo program, and the tools that are being developed to extract the maximal information from the data. We pay special attention to the compositional modeling technique that uses an implementation of a nested sampling algorithm for Bayesian inference of the abundances and grain sizes distribution of the materials present on TNOs surfaces.

 

 
A molecular toolkit to hunt and resolve Fungal Dark Matter (FDM) in extreme planetary environments
Authors: Nawaz Ali , Wurzbacher Christian
Published: September 2022

Fungi are amazing but largely enigmatic creatures with huge diversity and biological potentials in any conceivable ecosystem known so far. This holds for our planet but now this also seems to be true for outer space and other planetary bodies. However, we do not know what kind of extremophile fungi are or had been growing on other planets. To have a clue we need to explore the extreme analogue sites on our planet. The traditional methods used in the field of microbial ecology are definitely not sufficient to study those enigmatic group of fungi. Therefore, the filed extreme analogue sites need to be studied by using novel but advance molecular methods. In this regard, we collected and study samples from samples from various habitats of Matis - Iceland using a unique combination of Laser-microdissection of single cells and long-read sequencing to fully resolve the Fungal Dark Matter (FDM) of Mars-analogue extreme sites of Iceland. The findings of the project will help the wider scientific community dealing in AstroMycology in specific and Astrobiology in general to rightly speculate the capabilities and limitations of fungal life in extreme environments and correlate it with the conditions of other planets.
Nonlinear tidal interactions in the convective envelopes of low-mass stars and giant gaseous planets
Authors: Astoul Aurélie , Barker Adrian
Published: September 2022

In close exoplanetary systems, tidal interactions are known to shape the orbital architecture of the system, modify star and planet spins, and have an impact on the internal structure of the bodies through tidal heating. Most stars around which planets have been discovered are low-mass stars and thus feature a magnetised convective envelope, as is also expected in giant gaseous planets like Hot-Jupiter. Tidal flows, and more specifically inertial waves (restored by the Coriolis acceleration, and recently discovered in the Sun) tidally-excited, are the main direct manifestation of tidal interactions in the convective envelopes of these bodies. Furthermore, inertial waves are small-scale waves that are sensitive to nonlinearities, especially in close Hot-Jupiter systems with strong tidal forcing. The nonlinear self-interaction of inertial waves is known to trigger differential rotation in convective shells, as shown in numerical and experimental hydrodynamical studies. Since inertial waves are a key contribution to the tidal dissipation in close star-planet systems, it is essential to have the finest understanding of tidal inertial wave propagation and dissipation in such a complex nonlinear, magnetised, and differentially rotating environment.
In this context, we investigate how nonlinearities affect the tidal flow properties, thanks to new 3D hydrodynamic and magneto-hydrodynamic nonlinear simulations of tides, in an adiabatic and incompressible convective shell. First, we show to what extent the emergence of differential rotation is modifying the tidal dissipation rates, prior to linear predictions. In this newly generated zonal flows, nonlinear self-interactions of tidal inertial waves can also trigger different kind of instabilities and resonances between the waves and the background sheared flow, when the tidal forcing is strong enough or the viscosity low enough. These different processes disrupt the energetic exchanges between tidal waves and the background flow, and also further modifies the tidal dissipation rates. Secondly, we present the first non-linear numerical analysis of tidal flows in a magnetised convective shell. One main effect of the magnetic field in our model is to mitigate zonal flows triggered by the nonlinear interaction of inertial waves. The consequences for tidal flows are important, since the installation of zonal flows in nonlinear hydrodynamical simulations is the main cause of significant changes in tidal dissipation and angular momentum exchanges, compared to linear predictions for a uniformly rotating body. 