Search

There is a lack of exoplanets with sizes similar to Neptune orbiting their host stars with periods $\lesssim 3$ days -- hence the name ``sub-Jovian/Neptune desert''. Recently, several exoplanets have been confirmed to reside in the desert transforming it into a ``savanna'' with several ``giraffe'' planets (such as LTT 9779 b and TOI-674 b). The most prominent scenarios put forward for the explanation of the formation of the desert are related to the stellar irradiation destroying the primary atmosphere of certain specific exoplanets. We aim to present three targets (LTT 9779 b, TOI-674 b and WASP-156 b) which, when observed at wide wavelength ranges in infrared (IR), could prove the presence of these processes, and therefore improve the theories of planetary formation/evolution. We simulate and analyse realistic light curves of the selected exoplanets with PLATO/NCAM and the three narrow-band filters of Ariel (VISPhot, FGS1 and FGS2) based on TESS observations of these targets. We improved the precision of the transit parameters of the three considered planets from the TESS data. We find that the combination of the three narrow-band filters of Ariel can yield inner precision of $\lesssim 1.1\%$ for the planetary radii. Data from the three telescopes together will span decades, allowing the monitoring of changes in the planetary atmosphere through radius measurements. The three selected ``giraffe'' planets can be golden targets for Ariel, whereby the loss of planetary mass due to stellar irradiation could be studied with high precision, multi-wavelength (spectro-)photometry., Comment: Accepted for publication in MNRAS; 16 pages, 17 figures

An exomoon on a non perfectly circular orbit experiences tidal heating that is capable to significantly contribute to the thermal brightness of the moon. Here we argue that the thermal heat is unevenly distributed on the moon's surface, the emission of the tidal heat is limited to a few hot spots on the surface. A well-known example is the tidally heated Io. Due to their significantly increased temperature, the hot spots enhance the energy emission in thermal wavelengths. We made simulations using Monte-Carlo method to examine this contribution, and to predict about the possible detectability of such a spotted exomoon. We found that in the case of large, Earth sized companions to jupiters around red dwarf stars exhibit a thermal flux that enables the direct detection of the moon, due to its photometric signal that can exceed $\approx$100 ppm in the most favourable configurations., Accepted by MNRAS, 16 pages

The K2 mission of the Kepler Space Telescope allowed the observations of light curves of small solar system bodies throughout the whole Solar system. In this paper we present the results of a collection of K2 transneptunian object observations, between Campaigns C03 (November 2014 -- February 2015) to C19 (August -- September, 2018), which includes 66 targets. Due to the faintness of our targets the detectability rate of a light curve period is $\sim$56%, notably lower than in the case of other small body populations, like Hildas or Jovian trojans. We managed to obtain light curve periods with an acceptable confidence for 37 targets; the majority of these cases are new identifications. We were able to give light curve amplitude upper limits for the other 29 targets. Several of the newly detected light curve periods are longer than $\sim$24 h, in many cases close to $\sim$80 h, i.e., these targets are slow rotators. This relative abundance of slowly rotating objects is similar to that observed among Hildas, Jovian trojans and Centaurs in the K2 mission, and also among main belt asteroids measured with the TESS Space Telescope. Transneptunian objects show notably higher light curve amplitudes at large (D $\gtrsim$ 300 km) sizes than that found among large main belt asteroids, in contrast to the general expectation that due to their lower compressive strength they reach hydrostatic equlibrium at smaller sizes than their inner solar system counterparts., Accepted for publication in ApJS

Delrez, L., et al., Exoplanets transiting bright nearby stars are key objects for advancing our knowledge of planetary formation and evolution. The wealth of photons from the host star gives detailed access to the atmospheric, interior and orbital properties of the planetary companions. ν Lupi (HD 136352) is a naked-eye (V = 5.78) Sun-like star that was discovered to host three low-mass planets with orbital periods of 11.6, 27.6 and 107.6 d via radial-velocity monitoring. The two inner planets (b and c) were recently found to transit, prompting a photometric follow-up by the brand new Characterising Exoplanets Satellite (CHEOPS). Here, we report that the outer planet d is also transiting, and measure its radius and mass to be 2.56 ± 0.09 R and 8.82 ± 0.94 M, respectively. With its bright Sun-like star, long period and mild irradiation (~5.7 times the irradiation of Earth), ν Lupi d unlocks a completely new region in the parameter space of exoplanets amenable to detailed characterization. We refine the properties of all three planets: planet b probably has a rocky mostly dry composition, while planets c and d seem to have retained small hydrogen–helium envelopes and a possibly large water fraction. This diversity of planetary compositions makes the ν Lupi system an excellent laboratory for testing formation and evolution models of low-mass planets., The MOC activities have been supported by ESA contract 4000124370. S.C. acknowledges financial support by LabEx UnivEarthS (ANR-10-LABX-0023 and ANR-18-IDEX-0001). This work was supported by FCT (Fundação para a Ciência e a Tecnologia) through national funds and by FEDER (Fundo Europeu de Desenvolvimento Regional) through COMPETE2020—Programa Operacional Competitividade e Internacionalização with these grants: UID/FIS/04434/2019; UIDB/04434/2020; UIDP/04434/2020; PTDC/FIS-AST/32113/2017 and POCI-01-0145-FEDER-032113; PTDC/FIS-AST/28953/2017 and POCI-01-0145-FEDER-028953; PTDC/FIS-AST/28987/2017 and POCI-01-0145-FEDER-028987. S.C.C.B., S.G.S. and V.A. acknowledge support from FCT through contracts IF/01312/2014/CP1215/CT0004, CEECIND/00826/2018, POPH/FSE (EC) and IF/00650/2015/CP1273/CT0001. O.D.S.D. is supported in the form of a work contract (DL 57/2016/CP1364/CT0004) with national funds through FCT. M.J.H. acknowledges the support of the Swiss National Fund under grant 200020_172746. A.D. and D.E. acknowledge support from the European Research Council under the European Union’s Horizon 2020 research and innovation programme (project Four Aces; grant agreement 724427). S.H. acknowledges CNES funding through grant 837319. The Spanish scientific participation in CHEOPS has been supported by the Spanish Ministry of Science and Innovation and the European Regional Development Fund through grants ESP2016-80435-C2-1-R, ESP2016-80435-C2-2-R, ESP2017-87676-C5-1-R, PGC2018-098153-B-C31, PGC2018-098153-B-C33 and MDM-2017-0737 Unidad de Excelencia María de Maeztu–Centro de Astrobiología (INTA-CSIC), as well as by the Generalitat de Catalunya/CERCA programme. The Belgian participation in CHEOPS has been supported by the Belgian Federal Science Policy Office in the framework of the PRODEX Programme of the ESA under contract PEA 4000131343, and by the University of Liège through an ARC grant for Concerted Research Actions financed by the Wallonia–Brussels Federation. L.D. is an FRS-FNRS Postdoctoral Researcher. M. Gillon is an FRS–FNRS Senior Research Associate. V.V.G. is an FRS–FNRS Research Associate. M.L. acknowledges support from the Austrian Research Promotion Agency (FFG) under project 859724 ‘GRAPPA’. B.-O.D. acknowledges support from the Swiss National Science Foundation (PP00P2-190080). S. Salmon has received funding from the European Research Council under the European Union’s Horizon 2020 research and innovation programme (grant agreement 833925, project STAREX). G.M.S. acknowledges funding from the Hungarian National Research, Development and Innovation Office (NKFIH) grant GINOP-2.3.2-15-2016-00003 and K-119517. For Italy, CHEOPS activities have been supported by the Italian Space Agency, under the programmes ASI-INAF 2013-016-R.0 and ASI-INAF 2019-29-HH.0. L.B., G.P., I.P., G.S. and V.N. acknowledge funding support from the Italian Space Agency (ASI) regulated by ‘Accordo ASI-INAF 2013-016-R.0 del 9 luglio 2013 e integrazione del 9 luglio 2015’. A.C.C. and T.G.W. acknowledge support from STFC consolidated grant ST/M001296/1. D.G., X.B., S.C., M.F. and J.L. acknowledge their roles as ESA-appointed CHEOPS science team members. We thank S. R. Kane for sharing some RV data before their publication and L. D. Nielsen for helping to plan the CHEOPS observations on the basis of her analysis of the TESS data. We also thank M. Cretignier for his independent analysis of the HARPS RV data.

We present 17 transit light curves of seven known warm-Jupiters observed with the CHaracterising ExOPlanet Satellite (CHEOPS). The light curves have been collected as part of the CHEOPS Guaranteed Time Observation (GTO) program that searches for transit-timing variation (TTV) of warm-Jupiters induced by a possible external perturber to shed light on the evolution path of such planetary systems. We describe the CHEOPS observation process, from the planning to the data analysis. In this work, we focused on the timing performance of CHEOPS, the impact of the sampling of the transit phases, and the improvement we can obtain by combining multiple transits together. We reached the highest precision on the transit time of about 13-16 s for the brightest target (WASP-38, G = 9.2) in our sample. From the combined analysis of multiple transits of fainter targets with G ≥ 11, we obtained a timing precision of ∼2 min. Additional observations with CHEOPS, covering a longer temporal baseline, will further improve the precision on the transit times and will allow us to detect possible TTV signals induced by an external perturber., The early support for CHEOPS by Daniel Neuenschwander is gratefully acknowledged. GPi, VN, GSs, IPa, LBo, GLa, and RRa acknowledge the funding support from Italian Space Agency (ASI) regulated by ‘Accordo ASI-INAF n. 2013-016-R.0 del 9 luglio 2013 e integrazione del 9 luglio 2015 CHEOPS Fasi A/B/C’. GLa acknowledges support by CARIPARO Foundation, according to the agreement CARIPARO-Università degli Studi di Padova (Pratica n. 2018/0098), and scholarship support by the ‘Soroptimist International d’Italia’ association (Cortina d’Ampezzo Club). VVG is an FRS-FNRS Research Associate. VVG, LD, and MG thank the Belgian Federal Science Policy Office (BELSPO) for the provision of financial support in the framework of the PRODEX Programme of the European Space Agency (ESA) under contract number PEA 4000131343. DG, MF, SC, XB, and JL acknowledge their roles as ESA-appointed CHEOPS science team members. ZG was supported by the Hungarian NKFI grant No. K-119517 and the GINOP grant No. 2.3.2-15-2016-00003 of the Hungarian National Research Development and Innovation Office, by the City of Szombathely under agreement No. 67.177-21/2016, and by the VEGA grant of the Slovak Academy of Sciences No. 2/0031/18. This work was supported by FCT - Fundação para a Ciência e a Tecnologia through national funds and by FEDER through COMPETE2020 - Programa Operacional Competitividade e Internacionalização by these grants: UID/FIS/04434/2019; UIDB/04434/2020; UIDP/04434/2020; PTDC/FIS-AST/32113/2017 and POCI-01-0145-FEDER-032113; PTDC/FIS-AST/28953/2017 and POCI-01-0145-FEDER-028953; PTDC/FIS-AST/28987/2017 and POCI-01-0145-FEDER-028987. ACC and TGW acknowledge support from STFC consolidated grant No. ST/M001296/1. SH acknowledges CNES funding through the grant 837319. ODSD is supported in the form of work contract (DL 57/2016/CP1364/CT0004) funded by national funds through Fundação para a Ciência e Tecnologia (FCT). This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (project FOUR ACES; grant agreement No. 724427).

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited., In this paper we describe the photometry instruments of Ariel, consisting of the VISPhot, FGS1 and FGS2 photometers in the visual and mid-IR wavelength. These photometers have their own cadence, which can be independent from each other and the cadence of the spectral instruments. Ariel will be capable to do high cadence and high precision photometry in independent bands. There is also a possibility for synthetic Jsynth, Hsynth, and wide-band thermal infrared photometry from spectroscopic data. Although the cadence of the synthetic bands will be identical to that of the spectrographs, the precision of synthetic photometry in the suggested synthetic bands will be at least as precise as the optical data. We present the accuracy of these instruments. We also review selected fields of new science which will be opened up by the possibility of high cadence multiband space photometry, including stellar rotation, spin-orbit misalignment, orbital precession, planetary rotation and oblateness, tidal distortions, rings, and moons. © 2021, The Author(s)., This work has been supported by the Hungarian National Research, Development and Innovation Office (NKFI) grants K-119517, K-115709, and GINOP-2.3.2-15-2016-00003, the Lendület Program of the Hungarian Academy of Sciences, project No. LP2018-7/2020, and the City of Szombathely under agreement No. S-11-1027. L.V.M. and E.P. was supported by the ASI grant n. 2018.22.HH.O. ZG and TP acknowledge support from the VEGA grant of the Slovak Academy of Sciences No. 2/0031/18 and by the grant of the Slovak Research and Development Agency number APVV-15-0458. LBo acknowledges the funding support from Italian Space Agency (ASI) regulated by “Accordo ASI-INAF n. 2013-016-R.0 del 9 luglio 2013 e integrazione del 9 luglio 2015 CHEOPS Fasi A/B/C”., With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709.

In this paper, we analyze 10 globular clusters in order to measure their rotational properties by using high precision radial velocity data from the SDSS-IV APOGEE-2 survey. Out of the 10 clusters we were able to successfully measure the rotation speed and position angle of the rotation axis for 9 clusters (M2, M3, M5, M12, M13, M15, M53, M92, M107). The comparison between our results and previous ones shows a really good agreement within our uncertainties. For four of the globular clusters, M3, M13, M5 and M15, we separated the sample into two generation of stars using their [Al/Fe] abundances and examined the kinematic features of these generations separately from one another. In case of M3, we found significant difference between the rotational properties of first and second populations, confirming for the first time the predictions of several numerical simulations from the literature. The other three clusters (M5, M13, M15) also show smaller deviation between the two groups of stars, but those deviations are comparable to our errors., 9 pages, 3 figures, 4 tables. Accepted for publication in MNRAS

Extreme debris disks (EDDs) are rare systems with peculiarly large amounts of warm dust that may stem from recent giant impacts between planetary embryos during the final phases of terrestrial planet growth. Here we report on the identification and characterization of six new EDDs. These disks surround F5-G9 type main-sequence stars with ages >100 Myr, have dust temperatures higher than 300K and fractional luminosities between 0.01 and 0.07. Using time-domain photometric data at 3.4 and 4.6$��$m from the WISE all sky surveys, we conclude that four of these disks exhibited variable mid-infrared emission between 2010 and 2019. Analyzing the sample of all known EDDs, now expanded to 17 objects, we find that 14 of them showed changes at 3-5$��$m over the past decade suggesting that mid-infrared variability is an inherent characteristic of EDDs. We also report that wide-orbit pairs are significantly more common in EDD systems than in the normal stellar population. While current models of rocky planet formation predict that the majority of giant collisions occur in the first 100 Myr, we find that the sample of EDDs is dominated by systems older than this age. This raises the possibility that the era of giant impacts may be longer than we think, or that some other mechanism(s) can also produce EDDs. We examine a scenario where the observed warm dust stems from the disruption and/or collisions of comets delivered from an outer reservoir into the inner regions, and explore what role the wide companions could play in this process., 39 pages, 11 figures, accepted for publication in ApJ

Various properties of Jovian trojan asteroids such as composition, rotation periods, and photometric amplitudes, or the rate of binarity in the population can provide information and constraints on the evolution of the group and of the Solar System itself. Here we present new photometric properties of 45 Jovian trojans from the K2 mission of the Kepler space telescope, and present phase-folded light curves for 44 targets, including (11351) Leucus, one of the targets of the Lucy mission. We extend our sample to 101 asteroids with previous K2 Trojan measurements, then compare their combined amplitude- and frequency distributions to other ground-based and space data. We show that there is a dichotomy in the periods of Trojans with a separation at $\sim 100$ hr. We find that 25% of the sample are slow rotators (P$\geq$30 hr), which excess can be attributed to binary objects. We also show that 32 systems can be classified as potential detached binary systems. Finally, we calculate density and rotation constraints for the asteroids. Both the spin barrier and fits to strengthless ellipsoid models indicate low densities and thus compositions similar to cometary and TNO populations throughout the sample. This supports the scenario of outer Solar System origin for Jovian trojans., Comment: 25 pages, 19 figures, accepted for publication in ApJS

The Transit Timing Variation (TTV) technique is a powerful dynamical tool to measure exoplanetary masses by analysing transit light curves. We assessed the transit timing performances of the Ariel Fine Guidance Sensors (FGS1/2) based on the simulated light curve of a bright, 55 Cnc, and faint, K2-24, planet-hosting star. We estimated through a Markov-Chain Monte-Carlo analysis the transit time uncertainty at the nominal cadence of 1 second and, as a comparison, at a 30 and 60-s cadence. We found that at the nominal cadence Ariel will be able to measure the transit time with a precision of about 12s and 34s, for a star as bright as 55 Cnc and K2-24, respectively. We then ran dynamical simulations, also including the Ariel timing errors, and we found an improvement on the measurement of planetary masses of about $20-30\%$ in a K2-24-like planetary system through TTVs. We also simulated the conditions that allow us to detect the TTV signal induced by an hypothetical external perturber within the mass range between Earth and Neptune using 10 transit light curves by Ariel., Comment: 15 pages, 8 figures, accepted for publication in Experimental Astronomy - Ariel Special Issue

We thank the anonymous referee for comments that improved the manuscript. The authors thank the Belgian Federal Science Policy Office (BELSPO) for the provision of financial support in the framework of the PRODEX Programme of the European Space Agency (ESA) under contract number PEA 4000131343. This work has been supported by the University of Liege through an ARC grant for Concerted Research Actions financed by the Wallonia-Brussels Federation. The authors acknowledge support from the Swiss NCCR PlanetS and the Swiss National Science Foundation. V.V.G. is a F.R.S.-FNRS Research Associate. M.G. is an F.R.S.-FNRS Senior Research Associate. St.C. acknowledges financial support from the Centre National d'Etudes Spatiales (CNES, France) and from the Agence Nationale de la Recherche (ANR, France) under grant ANR-17-CE31-0018. K.G.I. is the ESA CHEOPS Project Scientist and is responsible for the ESA CHEOPS Guest Observers Programme. She does not participate in, or contribute to, the definition of the Guaranteed Time Programme of the CHEOPS mission through which observations described in this paper have been taken, nor to any aspect of target selection for the programme. D.E. has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (project FOUR ACES; grant agreement No 724427). This project has been carried out in the frame of the National Centre for Competence in Research PlanetS supported by the Swiss National Science Foundation (SNSF). G.B. acknowledges support from CHEOPS ASI-INAF agreement n. 2019-29-HH.0. A.J.M. acknowledges funding from the Swedish Research Council (starting grant 2017-04945) and the Swedish National Space Agency (career grant 120/19C). A.C.C. and T.G.W. acknowledge support from STFC consolidated grant number ST/M001296/1. A.B. was supported by the SNSA. M.F. gratefully acknowledge the support of the Swedish National Space Agency (DNR 65/19, 174/18). S.H. acknowledges CNES funding through the grant 837319. S.C.C.B. acknowledges support from FCT through FCT contracts nr. IF/01312/2014/CP1215/CT0004. S.G.S. acknowledge support from FCT through FCT contract nr. CEECIND/00826/2018 and POPH/FSE (EC). This work was supported by FCT -Fundacao para a Ciencia e a Tecnologia through national funds and by FEDER through COMPETE2020 -Programa Operacional Competitividade e Internacionalizacao by these grants: UID/FIS/04434/2019; UIDB/04434/2020; UIDP/04434/2020; PTDC/FIS-AST/32113/2017 & POCI-01-0145-FEDER032113; PTDC/FIS-AST/28953/2017 & POCI-01-0145-FEDER-028953; PTDC/FIS-AST/28987/2017 & POCI-01-0145-FEDER-028987. O.D.S.D. is supported in the form of work contract (DL 57/2016/CP1364/CT0004) funded by national funds through FCT. B.-O.D. acknowledges support from the Swiss National Science Foundation (PP00P2-190080). B.N.B. acknowledges funding through the TESS Guest Investigator Program Grant 80NSSC21K0364. We acknowledge support from the Spanish Ministry of Science and Innovation and the European Regional Development Fund through grants ESP2016-80435-C2-1-R, ESP2016-80435-C2-2-R, PGC2018-098153-B-C33, PGC2018-098153-B-C31, ESP2017-87676-C5-1-R, MDM-2017-0737 Unidad de Excelencia "Maria de Maeztu"-Centro de Astrobiologia (INTA-CSIC), as well as the support of the Generalitat de Catalunya/CERCA programme. The MOC activities have been supported by the ESA contract No. 4000124370. I.R. acknowledges support from the Spanish Ministry of Science and Innovation and the European Regional Development Fund through grant PGC2018-098153-BC33, as well as the support of the Generalitat de Catalunya/CERCA programme. X.B., Se.C., D.G., M.F. and J.L. acknowledge their role as ESA-appointed CHEOPS science team members. D.G. gratefully acknowledges financial support from the CRT foundation under Grant No. 2018.2323 "Gaseous or rocky? Unveiling the nature of small worlds". P.F.L.M. acknowledges support from STFC research grant number ST/M001040/1. This project has been supported by the Hungarian National Research, Development and Innovation Office (NKFIH) grants GINOP-2.3.2-15-2016-00003, K-119517, K-125015, and the City of Szombathely under Agreement No. 67.177-21/2016. This paper includes data collected by the TESS mission. Funding for the TESS mission is provided by the NASA Explorer Program. Funding for the TESS Asteroseismic Science Operations Centre is provided by the Danish National Research Foundation (Grant agreement no.: DNRF106), ESA PRODEX (PEA 4000119301) and Stellar Astrophysics Centre (SAC) at Aarhus University. We thank the TESS team and staff and TASC/TASOC for their support of the present work. This work has made use of data from the ESA mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium).Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement., Context. Hot subdwarfs experienced strong mass loss on the red giant branch (RGB) and are now hot and small He-burning objects. These stars constitute excellent opportunities for addressing the question of the evolution of exoplanetary systems directly after the RGB phase of evolution. Aims. In this project we aim to perform a transit survey in all available light curves of hot subdwarfs from space-based telescopes (Kepler, K2, TESS, and CHEOPS) with our custom-made pipeline SHERLOCK in order to determine the occurrence rate of planets around these stars as a function of orbital period and planetary radius. We also aim to determine whether planets that were previously engulfed in the envelope of their red giant host star can survive, even partially, as a planetary remnant. Methods. For this first paper, we performed injection-and-recovery tests of synthetic transits for a selection of representative Kepler, K2, and TESS light curves to determine which transiting bodies in terms of object radius and orbital period we will be able to detect with our tools. We also provide estimates for CHEOPS data, which we analyzed with the pycheops package. Results. Transiting objects with a radius less than or similar to 1.0 R-circle times can be detected in most of the Kepler, K2, and CHEOPS targets for the shortest orbital periods (1 d and shorter), reaching values as low as similar to 0.3 R-circle times in the best cases. Sub-Earth-sized bodies are only reached for the brightest TESS targets and for those that were observed in a significant number of sectors. We also give a series of representative results for larger planets at greater distances, which strongly depend on the target magnitude and on the length and quality of the data. Conclusions. The TESS sample will provide the most important statistics for the global aim of measuring the planet occurrence rate around hot subdwarfs. The Kepler, K2, and CHEOPS data will allow us to search for planetary remnants, that is, very close and small (possibly disintegrating) objects., European Space Agency European Commission PEA 4000131343, University of Liege through an ARC grant for Concerted Research Actions - Wallonia-Brussels Federation, Swiss NCCR PlanetS, Swiss National Science Foundation (SNSF) European Commission, Centre National D'etudes Spatiales, French National Research Agency (ANR) ANR-17-CE31-0018, European Research Council (ERC) 724427, Swiss National Science Foundation (SNSF), CHEOPS ASI-INAF 2019-29-HH.0, Swedish Research Council European Commission 2017-04945, Swedish National Space Agency 120/19C - DNR 65/19 - 174/18, UK Research & Innovation (UKRI) Science & Technology Facilities Council (STFC) ST/M001296/1- ST/M001040/1, SNSA, Centre National D'etudes Spatiales 837319, European Commission European Commission Joint Research Centre European Social Fund (ESF), Portuguese Foundation for Science and Technology DL 57/2016/CP1364/CT0004 - IF/01312/2014/CP1215/CT0004 - CEECIND/00826/2018, European Commission UID/FIS/04434/2019 - UIDB/04434/2020 - UIDP/04434/2020 - PTDC/FIS-AST/32113/2017 - POCI-01-0145-FEDER032113 - PTDC/FIS-AST/28953/2017 - POCI-01-0145-FEDER-028953 - PTDC/FIS-AST/28987/2017 - POCI-01-0145-FEDER-028987, Swiss National Science Foundation (SNSF) European Commission PP00P2-190080, TESS Guest Investigator Program Grant 80NSSC21K0364, Spanish Government, European Commission ESP2016-80435-C2-1-R - ESP2016-80435-C2-2-R - PGC2018-098153-B-C33 - PGC2018-098153-B-C31 - ESP2017-87676-C5-1-R - MDM-2017-0737 - PGC2018-098153-BC33, Generalitat de Catalunya/CERCA programme, European Space Agency 4000124370, CRT foundation 2018.2323, National Research, Development & Innovation Office (NRDIO) - Hungary GINOP-2.3.2-15-2016-00003 - K-119517 - K-125015, City of Szombathely 67.177-21/2016, National Aeronautics & Space Administration (NASA), Danmarks Grundforskningsfond DNRF106, European Space Agency PEA 4000119301, Stellar Astrophysics Centre (SAC) at Aarhus University, TASC/TASOC, Gaia Multilateral Agreement, DPAC

Due to their faintness light curves of transneptunian objects (TNOs) in most cases are difficult to obtain, and therefore the number of TNOs with known rotational properties (at least rotation period) are rather limited. As it was shown for other small body populations, long-term, 1-3-month monitoring of small bodies revealed many targets with long rotation periods. These measurements significantly increased the number of slow rotators (P > 24h) for Jovian Trojans (Szabó et al., 2017), Hildas (Szabó et al., 2020) and Centaurs (Marton et al., 2020) using Kepler/K2 measurements, and also for main belt asteroids (Pál et al., 2020) using the TESS space telescope. Here we report on Kepler/K2 measurements of 70 TNOs, collected over the whole length of the K2 mission, in Campaigns 3-19. Our data notably increases the number of TNOs with known rotational properties. We compare these characteristics with those of other small body populations in the Solar system. Figure 1: Light curve of (50000) Quaoar obtained from the K2 measurements, folded with the canonical P = 8.84 h period (Ortiz et al., 2003, left), and with the newly determined P = 8.88h rotation period (right). References: - Marton, G., et al., 2020, Icarus, 345, 113721 - Ortiz, J.L., et al., 2003, A&A, 409, L13- Pál, A., et al., 2020, ApJS, 247, 26 - Szabó, Gy. et al., 2017, A&A, 599, A44 - Szabó, Gy. et al., 2020, ApJS, 247, 34

Only a few exoplanets are known to orbit around fast rotating stars. One of them is XO-6b, which orbits an F5V-type star. Shortly after the discovery, we started multicolor photometric and radial-velocity follow-up observations of XO-6b, using the telescopes of Astronomical Institute of the Slovak Academy of Sciences. Our main scientific goals were to better characterize the planetary system and to search for transit timing variations. We refined several planetary and orbital parameters. Based on our measurements, the planet XO-6b seems to be about 10% larger, which is, however, only about $2\sigma$ difference, but its orbit inclination angle, with respect to the plane of the sky, seems to be significantly smaller, than it was determined originally by the discoverers. In this case we found about $9.5\sigma$ difference. Moreover, we observed periodic transit timing variations of XO-6b with a semi-amplitude of about 14 min and with a period of about 450 days. There are two plausible explanations of such transit timing variations: (1) a third object in the system XO-6 causing light-time effect, or (2) resonant perturbations between the transiting planet XO-6b and another unknown low-mass planet in this system. From the O-C diagram we derived that the assumed third object in the system should have a stellar mass, therefore significant variations are expected in the radial-velocity measurements of XO-6. Since this is not the case, and since all attempts to fit radial velocities and O-C data simultaneously failed to provide a consistent solution, more realistic is the second explanation., Comment: Accepted for publication in MNRAS

Hilda asteroids orbit at the outer edge, or just outside of the Main Belt, occupying the 2:3 mean motion resonance with Jupiter. It is known that the group shows a mixed taxonomy that suggests the mixed origin of Hilda members, having migrated to the current orbit both from the outer Main Belt and from the Trojans swarms. But there are still few observations for comparative studies that help in understanding the Hilda group in deeper details. We identified 125 individual light curves of Hilda asteroids observed by the K2 mission. We found that despite of the mixed taxonomies, the Hilda group highly resembles to the Trojans in the distribution of rotation periods and amplitudes, and even the LR group (mostly C and X-type) Hildas follow this rule. Contrary to the Main Belt, Hilda group lacks the very fast rotators. The ratio of extremely slow rotators (P>100 h) is a surprising 18%, which is unique in the Solar System. The occurrence rate of asteroids with multiple periods (4%) and asteroids with three maxima in the light curves (5%) can be signs of high rate of binarity, which we can estimate as 25% within the Hilda group., ApJS, in press, 28 pages

Compared with previous space-borne surveys, the Transiting Exoplanet Survey Satellite (TESS) provides a unique and new approach to observe Solar System objects. While its primary mission avoids the vicinity of the ecliptic plane by approximately six degrees, the scale height of the Solar System debris disk is large enough to place various small body populations in the field-of-view. In this paper we present the first data release of photometric analysis of TESS observations of small Solar System Bodies, focusing on the bright end of the observed main-belt asteroid and Jovian Trojan populations. This data release, named TSSYS-DR1, contains 9912 light curves obtained and extracted in a homogeneous manner, and triples the number of bodies with unambiguous fundamental rotation characteristics, namely where accurate periods and amplitudes are both reported. Our catalogue clearly shows that the number of bodies with long rotation periods are definitely underestimated by all previous ground-based surveys, by at least an order of magnitude., ApJS, in press. Data are available from https://archive.konkoly.hu/pub/tssys/dr1/ (6.36G, in total)

We present a photometric detection of the first brightness dips of the unique variable star KIC 8462852 since the end of the Kepler space mission in 2013 May. Our regular photometric surveillance started in October 2015, and a sequence of dipping began in 2017 May continuing on through the end of 2017, when the star was no longer visible from Earth. We distinguish four main 1-2.5% dips, named "Elsie," "Celeste," "Skara Brae," and "Angkor", which persist on timescales from several days to weeks. Our main results so far are: (i) there are no apparent changes of the stellar spectrum or polarization during the dips; (ii) the multiband photometry of the dips shows differential reddening favoring non-grey extinction. Therefore, our data are inconsistent with dip models that invoke optically thick material, but rather they are in-line with predictions for an occulter consisting primarily of ordinary dust, where much of the material must be optically thin with a size scale <, 19 pages, 8 figures, accepted for publication in ApJL

The photometry of the minor body with extrasolar origin (1I/2017 U1) 'Oumuamua revealed an unprecedented shape: Meech et al. (2017) reported a shape elongation b/a close to 1/10, which calls for theoretical explanation. Here we show that the abrasion of a primordial asteroid by a huge number of tiny particles ultimately leads to such elongated shape. The model (called the Eikonal equation) predicting this outcome was already suggested in Domokos et al. (2009) to play an important role in the evolution of asteroid shapes., Comment: Accepted by the Research Notes of the AAS

The Characterizing ExOPlanet Satellite (CHEOPS) mission was selected in October 2012 by ESA as the first small mission. It will be a ultra-high precision photometer dedicated to the observation of transits of known exoplanets on bright stars, for which the mass has already been measured via ground-based spectroscopic surveys. Its precision will allow the accurate determination of the planetary radii and, by consequence, the planetary bulk density. CHEOPS will also unveil transiting exoplanets of interest for in-depth characterization, a legacy for future instruments suited to the spectroscopic characterization of exoplanetary atmospheres.

Globular clusters have proven to be essential to our understanding of many important astrophysical phenomena. Here we analyse spectroscopic observations of ten Halo globular clusters to determine their dark matter content, their tidal heating by the Galactic disc and halo, describe their metallicities and the likelihood that Newtonian dynamics explain their kinematics. We analyse a large number of members in all clusters, allowing us to address all these issues together, and we have included NGC 288 and M30 to overlap with previous studies. We find that any flattening of the velocity dispersion profiles in the outer regions of our clusters can be explained by tidal heating. We also find that all our GCs have M/L_V < 5, therefore, we infer the observed dynamics do not require dark matter, or a modification of gravity. We suggest that the lack of tidal heating signatures in distant clusters indicates the Halo is not triaxial. The isothermal rotations of each cluster are measured, with M4 and NGC 288 exhibiting rotation at a level of 0.9 +/- 0.1 km/s and 0.25 +/- 0.15 km/s, respectively. We also indirectly measure the tidal radius of NGC 6752, determining a more realistic figure for this cluster than current literature values. Lastly, an unresolved and intriguing puzzle is uncovered with regard to the cooling of the outer regions of all ten clusters.

Kepler-13Ab (= KOI-13.01) is a unique transiting hot Jupiter. It is one of very few known short-period planets orbiting a hot A-type star, making it one of the hottest planets currently known. The availability of Kepler data allows us to measure the planet's occultation (secondary eclipse) and phase curve in the optical, which we combine with occultations observed by warm Spitzer at 4.5 mic and 3.6 mic and a ground-based occultation observation in the Ks band (2.1 mic). We derive a day-side hemisphere temperature of 2,750 +- 160 K as the effective temperature of a black body showing the same occultation depths. Comparing the occultation depths with one-dimensional planetary atmosphere models suggests the presence of an atmospheric temperature inversion. Our analysis shows evidence for a relatively high geometric albedo, Ag= 0.33 +0.04 -0.06. While measured with a simplistic method, a high Ag is supported also by the fact that the one-dimensional atmosphere models underestimate the occultation depth in the optical. We use stellar spectra to determine the dilution, in the four wide bands where occultation was measured, due to the visual stellar binary companion 1.15 +- 0.05" away. The revised stellar parameters measured using these spectra are combined with other measurements leading to revised planetary mass and radius estimates of Mp = 4.94 - 8.09 Mjup and Rp = 1.406 +- 0.038 Rjup. Finally, we measure a Kepler mid-occultation time that is 34.0 +- 6.9 s earlier than expected based on the mid-transit time and the delay due to light travel time, and discuss possible scenarios., V2: Accepted to ApJ on 2014 April 11. Spitzer photometry and model fitting Matlab pipeline code is publicly available at: http://gps.caltech.edu/~shporer/spitzerphot/

We present the analysis of photometric and spectroscopic data of two classical Cepheids, FN Aquilae and V1344 Aquilae. Based on the joint treatment of the new and earlier radial velocity data, both Galactic Cepheids have been found to be a member in a spectroscopic binary system. To match the phases of the earlier radial velocity data correctly with the new ones, we also determined the temporal behaviour of the pulsation period of these Cepheids based on all available photometric data. The O-C graph covering about half century shows slight changes in the pulsation period due to stellar evolution for both Cepheids., 7 pages, 6 figures, 7 tables, accepted for publishing in the MNRAS

The globular cluster 47 Tucanae is well studied but it has many characteristics that are unexplained, including a significant rise in the velocity dispersion profile at large radii, indicating the exciting possibility of two distinct kinematic populations. In this Letter we employ a Bayesian approach to the analysis of the largest available spectral dataset of 47 Tucanae to determine whether this apparently two-component population is real. Assuming the two models were equally likely before taking the data into account, we find that the evidence favours the two-component population model by a factor of ~3x10^7. Several possible explanations for this result are explored, namely the evaporation of low-mass stars, a hierarchical merger, extant remnants of two initially segregated populations, and multiple star formation epochs. We find the most compelling explanation for the two-component velocity distribution is that 47 Tuc formed as two separate populations arising from the same proto-cluster cloud which merged, 14 pages, 2 figures, 1 table. Accepted for publication in ApJ Letters

A statistical analysis of brightness variability of asteroids reveals how their shapes evolve from elongated to rough spheroidal forms, presumably driven by impact-related phenomena. Based on the Sloan Digital Sky Survey Moving Object Catalog, we determined the shape distribution of 11,735 asteroids, with special emphasis on eight prominent asteroid families. In young families, asteroids have a wide range of shape elongations, implying fragmentation-formation. In older families we see an increasing number of rough spheroids, in agreement with the predictions of an impact-driven evolution. Old families also contain a group of moderately elongated members, which we suggest correspond to higher-density, more impact-resistant cores of former fragmented asteroids that have undergone slow shape erosion. A few percent of asteroids have very elongated shapes, and can either be young fragments or tidally reshaped bodies. Our results confirm that the majority of asteroids are gravitationally bound ``rubble piles''., Comment: Accepted by Icarus. 22 pages, 1 table, 6 figures, 31 figure panels

A class of generalized Randall-Sundrum type II (RS) brane-world models with Weyl fluid are confronted with the Gold supernovae data set and BBN constraints. We consider three models with different evolutionary history of the Weyl fluid, characterized by the parameter $\alpha$. For $\alpha=0$ the Weyl curvature of the bulk appears as dark radiation on the brane, while for $\alpha =2$ and 3 the brane radiates, leaving a Weyl fluid on the brane with energy density decreasing slower than that of (dark) matter. In each case the contribution $\Omega_d$ of the Weyl fluid represents but a few percent of the energy content of the Universe. All models fit reasonably well the Gold2006 data. The best fit model for $\alpha =0$ is for $\Omega_d=0.04$. In order to obey BBN constraints in this model however, the brane had to radiate at earlier times., Comment: 4 pages, 3 figures, to appear in the PASCOS-07 (13th International Symposium on Particles, Strings and Cosmology) Proceedings volume

Stardust grains that originated in ancient stars and supernovae are recovered from meteorites and carry the detailed composition of their astronomical sites of origin. We present evidence that the majority of large ($\mu$m-sized) meteoritic silicon carbide (SiC) grains formed in C-rich asymptotic giant branch (AGB) stars that were more metal-rich than the Sun. In the framework of the slow neutron-captures (the s process) that occurs in AGB stars the lower-than-solar 88Sr/86Sr isotopic ratios measured in the large SiC grains can only be accompanied by Ce/Y elemental ratios that are also lower than solar, and predominately observed in metal-rich barium stars - the binary companions of AGB stars. Such an origin suggests that these large grains represent the material from high-metallicity AGB stars needed to explain the s-process nucleosynthesis variations observed in bulk meteorites (Ek et al. 2020). In the outflows of metal-rich, C-rich AGB stars SiC grains are predicted to be small ($\simeq$ 0.2 $\mu$m-sized); large ($\simeq$ $\mu$m-sized) SiC grains can grow if the number of dust seeds is two to three orders of magnitude lower than the standard value of $10^{-13}$ times the number of H atoms. We therefore predict that with increasing metallicity the number of dust seeds might decrease, resulting in the production of larger SiC grains., Comment: accepted for publication in The Astrophysical Journal