Search results

We report the discovery and characterisation of a super-Earth and a sub-Neptune transiting the bright (K = 8:8), quiet, and nearby (37 pc) M3V dwarf TOI-1266. We validate the planetary nature of TOI-1266 b and c using four sectors of TESS photometry and data from the newly-commissioned 1-m SAINT-EX telescope located in San Pedro Mártir (México). We also include additional groundbased follow-up photometry as well as high-resolution spectroscopy and high-angular imaging observations. The inner, larger planet has a radius of R = 2:37+0:16 -0:12 R and an orbital period of 10.9 days. The outer, smaller planet has a radius of R = 1:56+0:15 -0:13 R on an 18.8-day orbit. The data are found to be consistent with circular, co-planar and stable orbits that are weakly influenced by the 2:1 mean motion resonance. Our TTV analysis of the combined dataset enables model-independent constraints on the masses and eccentricities of the planets. We find planetary masses of Mp = 13:5+11:0 -9:0 M (<36:8 M at 2- ) for TOI-1266 b and 2:2+2:0 -1:5 M (<5:7 M at 2- ) for TOI-1266 c. We find small but non-zero orbital eccentricities of 0:09+0:06 -0:05 (<0:21 at 2- ) for TOI-1266 b and 0:04 0:03 (<0:10 at 2- ) for TOI-1266 c. The equilibrium temperatures of both planets are of 413 20 and 344 16 K, respectively, assuming a null Bond albedo and uniform heat redistribution from the day-side to the night-side hemisphere. The host brightness and negligible activity combined with the planetary system architecture and favourable planet-to-star radii ratios makes TOI-1266 an exquisite system for a detailed characterisation. ; Embassy of Mexico in Bern ; Swiss National Science Foundation (SNSF) ; Programa de Apoyo a Proyectos de Investigacion e Innovacion Tecnologica (PAPIIT) Universidad Nacional Autonoma de Mexico IN-107518 ; DGAPA ; Australian Research Council ; Fonds de la Recherche Scientifique - FNRS FRFC 2.5.594.09 ; Swiss National Science Fundation (SNF) - University of Liege ; Spanish public funds for research ESP2017-87676-2-2 RYC-2012-09913 ; Spanish Government ; National Aeronautics & Space Administration (NASA) ; NASA High-End Computing (HEC) Program through the NASA ; Baja California, Mexico - Spanish State Research Agency (AEI) MDM-2017-0737 ; Unidad de Excelencia "Maria de Maeztu"- Centro de Astrobiologia (INTA-CSIC) ; Junta de Andalucía ; European Research Council (ERC) 336480 ; Alfred P. Sloan Foundation ; National Aeronautics & Space Administration (NASA) 80NSSC18K1585 80NSSC19K0379 ; National Science Foundation (NSF) AST-1717000 ; Antoine de Saint-Exupery Youth Foundation

Context.Teegarden's Star is the brightest and one of the nearest ultra-cool dwarfs in the solar neighbourhood. For its late spectral type (M7.0 V),the star shows relatively little activity and is a prime target for near-infrared radial velocity surveys such as CARMENES.Aims.As part of the CARMENES search for exoplanets around M dwarfs, we obtained more than 200 radial-velocity measurements of Teegarden'sStar and analysed them for planetary signals.Methods.We find periodic variability in the radial velocities of Teegarden's Star. We also studied photometric measurements to rule out stellarbrightness variations mimicking planetary signals.Results.We find evidence for two planet candidates, each with 1.1M⊕minimum mass, orbiting at periods of 4.91 and 11.4 d, respectively. Noevidence for planetary transits could be found in archival and follow-up photometry. Small photometric variability is suggestive of slow rotationand old age.Conclusions.The two planets are among the lowest-mass planets discovered so far, and they are the first Earth-mass planets around an ultra-cooldwarf for which the masses have been determined using radial velocities. ; We thank the referee Rodrigo Díaz for a careful review andhelpful comments. M.Z. acknowledges support from the Deutsche Forschungs-gemeinschaft under DFG RE 1664/12-1 and Research Unit FOR2544 "BluePlanets around Red Stars", project no. RE 1664/14-1. CARMENES isan instrument for the Centro Astronómico Hispano-Alemán de Calar Alto(CAHA, Almería, Spain). CARMENES is funded by the German Max-Planck-Gesellschaft (MPG), the Spanish Consejo Superior de InvestigacionesCientíficas (CSIC), the European Union through FEDER/ERF FICTS-2011-02 funds, and the members of the CARMENES Consortium (Max-Planck-Institut für Astronomie, Instituto de Astrofísica de Andalucía, LandessternwarteKönigstuhl, Institut de Ciències de l'Espai, Institut für Astrophysik Göttingen,Universidad Complutense de Madrid, Thüringer Landessternwarte Tautenburg,Instituto de Astrofísica de Canarias, Hamburger Sternwarte, Centro de Astro-biología and Centro Astronómico Hispano-Alemán), with additional contribu-tions by the Spanish Ministry of Economy, the German Science Foundationthrough the Major Research Instrumentation Programme and DFG ResearchUnit FOR2544 "Blue Planets around Red Stars", the Klaus Tschira Stiftung, thestates of Baden-Württemberg and Niedersachsen, and by the Junta de Andalucía.Based on data from the CARMENES data archive at CAB (INTA-CSIC). Thisarticle is based on observations made with the MuSCAT2 instrument, devel-oped by ABC, at Telescopio Carlos Sánchez operated on the island of Tener-ife by the IAC in the Spanish Observatorio del Teide. Data were partly col-lected with the 150-cm and 90-cm telescopes at the Sierra Nevada Observa-tory (SNO) operated by the Instituto de Astrofísica de Andalucía (IAA-CSIC).Data were partly obtained with the MONET/South telescope of the MOnitoringNEtwork of Telescopes, funded by the Alfried Krupp von Bohlen und HalbachFoundation, Essen, and operated by the Georg-August-Universität Göttingen,the McDonald Observatory of the University of Texas at Austin, and the SouthAfrican Astronomical Observatory. We acknowledge financial support from theSpanish Agencia Estatal de Investigación of the Ministerio de Ciencia, Inno-vación y Universidades and the European FEDER/ERF funds through projectsAYA2015-69350-C3-2-P, AYA2016-79425-C3-1/2/3-P, AYA2018-84089, BES-2017-080769, BES-2017-082610, ESP2015-65712-C5-5-R, ESP2016-80435-C2-1/2-R, ESP2017-87143-R, ESP2017-87676-2-2, ESP2017-87676-C5-1/2/5-R, FPU15/01476, RYC-2012-09913, the Centre of Excellence "Severo Ochoa"and "María de Maeztu" awards to the Instituto de Astrofísica de Canarias (SEV-2015-0548), Instituto de Astrofísica de Andalucía (SEV-2017-0709), and Cen-tro de Astrobiología (MDM-2017-0737), the Generalitat de Catalunya throughCERCA programme", the Deutsches Zentrum für Luft- und Raumfahrt throughgrants 50OW0204 and 50OO1501, the European Research Council through grant694513, the Italian Ministero dell'instruzione, dell'università de della ricerca andUniversità degli Studi di Roma Tor Vergata through FFABR 2017 and "Mis-sion: Sustainability 2016", the UK Science and Technology Facilities Council through grant ST/P000592/1, the Israel Science Foundation through grant848/16, the Chilean CONICYT-FONDECYT through grant 3180405, the Mexi-can CONACYT through grant CVU 448248, the JSPS KAKENHI through grantsJP18H01265 and 18H05439, and the JST PRESTO through grant JPMJPR1775.

Full list of authors: Demory, B. -O.; Pozuelos, F. J.; Gómez Maqueo Chew, Y.; Sabin, L.; Petrucci, R.; Schroffenegger, U.; Grimm, S. L.; Sestovic, M.; Gillon, M.; McCormac, J.; Barkaoui, K.; Benz, W.; Bieryla, A.; Bouchy, F.; Burdanov, A.; Collins, K. A.; de Wit, J.; Dressing, C. D.; Garcia, L. J.; Giacalone, S.; Guerra, P.; Haldemann, J.; Heng, K.; Jehin, E.; Jofré, E.; Kane, S. R.; Lillo-Box, J.; Maigné, V.; Mordasini, C.; Morris, B. M.; Niraula, P.; Queloz, D.; Rackham, B. V.; Savel, A. B.; Soubkiou, A.; Srdoc, G.; Stassun, K. G.; Triaud, A. H. M. J.; Zambelli, R.; Ricker, G.; Latham, D. W.; Seager, S.; Winn, J. N.; Jenkins, J. M.; Calvario-Velásquez, T.; Franco Herrera, J. A.; Colorado, E.; Cadena Zepeda, E. O.; Figueroa, L.; Watson, A. M.; Lugo-Ibarra, E. E.; Carigi, L.; Guisa, G.; Herrera, J.; Sierra Díaz, G.; Suárez, J. C.; Barrado, D.; Batalha, N. M.; Benkhaldoun, Z.; Chontos, A.; Dai, F.; Essack, Z.; Ghachoui, M.; Huang, C. X.; Huber, D.; Isaacson, H.; Lissauer, J. J.; Morales-Calderón, M.; Robertson, P.; Roy, A.; Twicken, J. D.; Vanderburg, A.; Weiss, L. M. ; We report the discovery and characterisation of a super-Earth and a sub-Neptune transiting the bright (K = 8.8), quiet, and nearby (37 pc) M3V dwarf TOI-1266. We validate the planetary nature of TOI-1266 b and c using four sectors of TESS photometry and data from the newly-commissioned 1-m SAINT-EX telescope located in San Pedro Mártir (México). We also include additional ground-based follow-up photometry as well as high-resolution spectroscopy and high-angular imaging observations. The inner, larger planet has a radius of R = 2.37-0.12+0.16 R and an orbital period of 10.9 days. The outer, smaller planet has a radius of R = 1.56-0.13+0.15 R on an 18.8-day orbit. The data are found to be consistent with circular, co-planar and stable orbits that are weakly influenced by the 2:1 mean motion resonance. Our TTV analysis of the combined dataset enables model-independent constraints on the masses and eccentricities of the planets. We find planetary masses of Mp = 13.5-9.0+11.0 M (<36.8 M at 2-σ) for TOI-1266 b and 2.2-1.5+2.0 M (<5.7 M at 2-σ) for TOI-1266 c. We find small but non-zero orbital eccentricities of 0.09-0.05+0.06 (<0.21 at 2-σ) for TOI-1266 b and 0.04 ± 0.03 (< 0.10 at 2-σ) for TOI-1266 c. The equilibrium temperatures of both planets are of 413 ± 20 and 344 ± 16 K, respectively, assuming a null Bond albedo and uniform heat redistribution from the day-side to the night-side hemisphere. The host brightness and negligible activity combined with the planetary system architecture and favourable planet-to-star radii ratios makes TOI-1266 an exquisite system for a detailed characterisation. © 2020 ESO. ; We warmly thank the entire technical staff of the Observatorio Astronomico Nacional at San Pedro Martir in Mexico for their unfailing support to SAINT-EX operations, namely: U. Cesena, A. Cordova, B. Garcia, C.A. Guerrero, F. Guillen, J.A. Hernandez, B. Hernandez, E. Lopez, B. Martinez, G. Melgoza, F. Montalvo, S. Monrroy,J.C. Narvaez, J.M. Nunez, J.L. Ochoa, I. Plauchu, F. Quiroz, H. Serrano, T. Verdugo. We gratefully acknowledgethe support from the Embassy of Mexico in Bern to the SAINT-EX project. We also thank the past members of the SAINT-EX team B. Courcol, E. Rose and K. Housen for their help in the course of the project. We are grateful to the anonymous referee for a thorough and helpful review of our paper. We thank Jonathan Irwin for his help on the TRES data analysis. B.-O.D. acknowledges support from the Swiss National Science Foundation (PP00P2-163967). This work has been carried out within the frame of the National Centre for Competence in Research PlanetS supported by the Swiss National Science Foundation. Y.G.M.C acknowledges support from UNAM-PAPIIT IN-107518. R.P. and E.J. acknowledge DGAPA for their postdoctoral fellowships. The research leading to these results has received funding from the ARC grant for Concerted Research Actions, financed by the Wallonia-Brussels Federation. TRAPPIST is funded by the Belgian Fund for Scientific Research (Fonds National de la Recherche Scientifique, FNRS) under the grant FRFC 2.5.594.09.F, with the participation of the Swiss National Science Fundation (SNF). TRAPPIST-North is a project funded by the University of Liege, and performed in collaboration with Cadi Ayyad University of Marrakesh. M.G. and E.J. are F.R.S.-FNRS Senior Research Associates. J.C.S. acknowledges funding support from Spanish public funds for research under projects ESP2017-87676-2-2 and RYC-2012-09913 (Ramon y Cajal programme) of the Spanish Ministry of Science and Education. This paper includes data collected by the TESS mission. We acknowledge the use of public TOI Release data from pipelines at the TESS Science Office and at the TESS Science Processing Operations Center. Funding for the TESS mission is provided by the NASA Explorer Program. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center for the production of the SPOC data products. This work is based upon observationscarried out at the Observatorio Astronomico Nacional on the Sierra de San Pedro Martir (OAN-SPM), Baja California, Mexico. This research has been partly funded by the Spanish State Research Agency (AEI) Projects No.ESP2017-87676-C5-1-R and No. MDM-2017-0737 Unidad de Excelencia "Maria de Maeztu"- Centro de Astrobiologia (INTA-CSIC). This paper is based on observations collected at Centro Astronomico Hispano en Andalucia (CAHA) at Calar Alto, operated jointly by Instituto de Astrofisica de Andalucia (CSIC) and Junta de Andalucia. The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Programme (FP/2007-2013) ERC Grant Agreement n o 336480 (SPECULOOS). D.H. acknowledges support from the Alfred P. Sloan Foundation, the National Aeronautics and Space Administration (80NSSC18K1585, 80NSSC19K0379), and the National Science Foundation (AST-1717000). We finally acknowledge support from the Antoine de Saint-Exupery Youth Foundation through their involvement in the educational programme of the SAINT-EX Observatory. With funding from the Spanish government through the "María de Maeztu Unit of Excellence" accreditation (MDM-2017-0737)

Fractal behaviour, i.e. scale invariance in spatio-temporal dynamics, has been found to describe and model many systems in nature, in particular fluid mechanics and geophysical related geometrical objects, like the convective boundary layer of cumulus cloud fields, topographic landscapes, solar granulation patterns, and observational astrophysical time series, like light curves of pulsating stars. The main interest in the study of fractal properties in such physical phenomena lies in the close relationships they have with chaotic and turbulent dynamic. In this work we introduce some statistical tools for fractal analysis of light curves: Rescaled Range Analysis (R/S), Multifractal Spectra Analysis, and Coarse Graining Spectral Analysis (CGSA), an FFT based algorithm, which can discriminate in a time series the stochastic fractal power spectra from the harmonic one. An interesting application of fractal analysis in asteroseismology concerns the joint use of all these tools in order to develop classification criteria and algorithms for ¿ Scuti pulsating stars. In fact from the fractal and multifractal fingerprints in the background noise of the light curves we could infer properties of different mechanisms of stellar dynamic, among them rotation, modes excitation and magnetic activity. © 2018 The Author(s). ; SdF, JPG and RG acknowledge funding support from Spanish public funds for research under projects ESP2015-65712-C5-3-R. JCS acknowledges funding support from Spanish public funds for research under projects ESP2017-87676-2-2 and ESP2015-65712-C5-5-R, and from project RYC-2012-09913 under the 'Ramon y Cajal' program of the Spanish MINECO. SdF, JPG and RG acknowledge support from the 'Junta de Andalucia' regional government under project 2012-P12-TIC-2469. ; Peer Reviewed

Reproduced with permission from Astronomy & Astrophysics, © ESO. ; We present a comprehensive asteroseismic study of the double-mode high-amplitude $\delta$ Scuti star HD 187642 ( RV Ari ). The modelling includes some of the most recent techniques: 1) effects of rotation on both equilibrium models and adiabatic oscillation spectrum, 2) non-adiabatic study of radial and non-radial modes, 3) relationship between the fundamental radial mode and the first overtone in the framework of Petersen diagrams. The analysis reveals that two of the observed frequencies are very probably identified as the fundamental and first overtone radial modes. Analysis of the colour index variations, together with theoretical non-adiabatic calculations, points to models in the range of [7065, 7245] K in effective temperature and of [1190, 1270] Myr in stellar age. These values were found to be compatible with those obtained using the three other asteroseismic techniques. ; This work was partially financed by the Spanish "Plan Nacional del Espacio'', under project ESP2004-03855-C03-01. J.C.S. acknowledges the financial support of the European Marie Curie action MERG-CT-2004-513610 and the Spanish "Consejería de Innovación, Ciencia y Empresa" from the "Junta de Andalucía" local government.

We present the first results from the Transiting Exoplanet Survey Satellite (TESS) on the rotational and pulsational variability of magnetic chemically peculiar A-type stars. We analyse TESS 2-min cadence data from sectors 1 and 2 on a sample of 83 stars. Five new rapidly oscillating Ap (roAp) stars are announced. One of these pulsates with periods around 4.7 min, making it the shortest period roAp star known to date. Four out of the five new roAp stars are multiperiodic. Three of these, and the singly-periodic one show the presence of rotational mode splitting. Individual frequencies are provided in all cases. In addition, seven previously known roAp stars are analysed. Additional modes of oscillation are found in some stars, while in others we are able to distinguish the true pulsations from possible aliases present in the ground-based data. We find that the pulsation amplitude in the TESS filter is typically a factor 6 smaller than that in the B filter which is usually used for ground-based observations. For four roAp stars we set constraints on the inclination angle and magnetic obliquity, through the application of the oblique pulsator model. We also confirm the absence of roAp-type pulsations down to amplitude limits of 6 and 13 micromag, respectively, in two of the best characterised non-oscillating Ap (noAp) stars. We announce 27 new rotational variables along with their rotation periods, and provide different rotation periods for seven other stars. Finally, we discuss how these results challenge state-of-the-art pulsation models for roAp stars. ; We thank the referee for very detailed and useful comments to the original manuscript. 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, PTDC/FIS-AST/30389/2017 & POCI-01- 0145-FEDER-030389. MC is supported in the form of work contract funded by national funds through FCT. Funding for the Stellar Astrophysics Centre is provided by The Danish National Research Foundation (Grant agreement no.: DNRF106). DLH and DWK acknowledge financial support from the Science and Technology Facilities Council (STFC) via grant ST/M000877/1. This work has made use of data from the European Space Agency (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. LFM acknowledges support from the UNAM by the way of DGAPA project PAPIIT IN100918. The research leading to these results has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement N 670519: MAMSIE) and from the Fonds Wetenschappelijk Onderzoek - Vlaanderen (FWO) under the grant agreement G0H5416N (ERC Opvangproject). MS acknowledges the financial support of Postdoc@MUNI project CZ.02.2.69/0.0/0.0/16 027/0008360. EN acknowledges the Polish National Science Center grants no.2014/13/B/ST9/00902. JCS acknowledges funding support from Spanish public funds for research under projects ESP2017-87676-2-2 and ESP2015- 65712-C5-5-R, and from project RYC-2012-09913 under the 'Ramón y Cajal' program of the Spanish Ministry of Science and Education. AGH acknowledges funding support from Spanish public funds for research under projects ESP2017-87676-2-2 and ESP2015-65712-C5-5-R of the Spanish Ministry of Science and Education. A´ S, ZsB, and RSz acknowledge the financial support of the GINOP-2.3.2-15-2016- 00003, K-115709, K-113117, K-119517 and PD-123910 grants of the Hungarian National Research, Development and Innovation Office (NKFIH), and the Lendület Program of the Hungarian Academy of Sciences, project No. LP2018-7/2018. GH has been supported by the Polish NCN grant 2015/18/A/ST9/00578. MLM acknowledges funding support from Spanish public funds for research under project ESP2015- 65712-C5-3-R. JPG acknowledges funding support from Spanish public funds for research under project ESP2017-87676-C5-5-R. MLM and JPG also acknowledges funding support from the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award for the Instituto de Astrofísica de Andalucía (SEV-2017-0709). IS acknowledges funding support of NSF under projects DN 08-1/2016 and DN 18/13-12.12.2017. P. Kołaczek-Szymański acknowledges support from the NCN grant no. 2016/21/B/ST9/01126. This paper includes data collected by the TESS mission. Funding for the TESS mission is provided by the NASA Explorer Program.

Thanks to high-precision photometric data legacy from space telescopes like CoRoT andKepler, the scientific community could detect and characterize the power spectra of hundreds of thousands of stars. Using the scaling relations, it is possible to estimate masses and radii for solar-type pulsators. However, these stars are not the only kind of stellar objects that follow these rules:delta Scuti stars seem to be characterized with seismic indexes such as the large separation (Delta nu). Thanks to long-duration high-cadence TESS light curves, we analysed more than two thousand of this kind of classical pulsators. In that way, we propose the frequency at maximum power (nu(max)) as a proper seismic index since it is directly related with the intrinsic temperature, mass and radius of the star. This parameter seems not to be affected by rotation, inclination, extinction or resonances, with the exception of the evolution of the stellar parameters. Furthermore, we can constrain rotation and inclination using the departure of temperature produced by the gravity-darkening effect. This is especially feasible for fast rotators as most of delta Scuti stars seem to be. © ESO 2020. ; We also thank the CoRoT, Kepler, and TESS teams whose efforts made these results possible. The CoRoT space mission was developed and operated by CNES, with contributions from Austria, Belgium, Brazil, ESA (RSSD and Science Program), Germany and Spain. Funding for Kepler's Discovery mission is provided by NASA's Science Mission Directorate. Funding for the TESS mission is provided by the NASA Explorer Program. The authors acknowledge the effort made by TASOC WG4 that helped us in our target selection. This publication makes use of VOSA, developed under the Spanish Virtual Observatory project supported by the Spanish MICIU through Grant AyA2017-84089. VOSA has been partially updated by using funding from the European Union's Horizon 2020 Research and Innovation Programme, under Grant Agreement No. 776403 (EXOPLANETS-A). SBF and DB received financial support from the Spanish State Research Agency (AEI) Projects No. ESP2017-87676-C5-1-R and No. MDM-2017-0737 Unidad de Excelencia "Maria de Maeztu"- Centro de Astrobiologia (INTA-CSIC). AM acknowledges funding from the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Grant agreement No. 749962 (project THOT). SMR acknowledges financial support from the State Agency for Research of the Spanish MICIU through the "Center of Excellence Severo Ochoa" award to the Instituto de Astrofisica de Andalucia (SEV-2017-0709). JCS and AGH acknowledge funding support from Spanish public funds (including FEDER fonds) for research under project ESP2017-87676-C5-2-R and ESP2017-87676-C5-5-R. JCS also acknowledges support from project RYC-2012-09913 under the "Ramon y Cajal" program of the Spanish Ministry of Science and Education. AGH acknowledges support from "Universidad de Granada" under project E-FQM-041-UGR18 from "Programa Operativo FEDER 2014-2020" programme by "Junta de Andalucia" regional Government. ; Peer reviewed

ARB, JPG, and RG acknowledge funding support from Spanish public funds for research from project ESP2017-87676-C5-5-R from the `Plan Estatal de Investigacion Cientifica y Tecnica y de Innovacion', from project PID2019-107061GB-C63 from the `Programas Estatales de Generacion de Conocimiento y Fortalecimiento Cientifico y Tecnologico del Sistema de I+D+i y de I+D + i Orientada a los Retos de la Sociedad', and from the State Agency for Research through the `Center of Excellence Severo Ochoa' award to the Instituto de Astrofisica de Andalucia (SEV-2017-0709), all from the Spanish Ministry of Science, Innovation and Universities. ARB also acknowledges funding support from project PRE2018084322 from the `Programa Estatal de Promocion del Talento y su Empleabilidad del Plan Estatal de Investigacion Cientifica y Tecnica y de Innovacion 2013-2016' of the Spanish Ministry of Science, Innovation and Universities. AGHacknowledges funding support from Spanish public funds for research under projects ESP2017-87676-2-2 the SpanishMinistry of Science and Education, and from `European Regional Development Fund/Junta de Andalucia-Consejeria de Economia y Conocimiento' under project E-FQM-041-UGR18 by Universidad de Granada. JCS acknowledges funding support from Spanish public funds for research under projects PID2019-107061GB-C63 and ESP201787676-2-2, and from project RYC-2012-09913 under the `Ramon y Cajal' program of the Spanish Ministry of Science and Education. ; Detecting and understanding rotation in stellar interiors is nowadays one of the unsolved problems in stellar physics. Asteroseismology has been able to provide insights on rotation for the Sun, solar-like stars, and compact objects like white dwarfs. However, this is still very difficult for intermediate-mass stars. These stars are moderate-to-rapid rotators. Rotation splits and shifts the oscillation modes, which makes the oscillation spectrum more complex and harder to interpret. Here we study the oscillation patterns of a sample of benchmark delta Sct stars belonging to eclipsing binary systems with the objective of finding the frequency spacing related to the rotational splitting (delta r). For this task, we combine three techniques: the Fourier transform, the autocorrelation function, and the histogram of frequency differences. The last two showed a similar behaviour. For most of the stars, it was necessary to determine the large separation (Delta nu) prior to spot delta r. This is the first time we may clearly state that one of the periodicities present in the p modes oscillation spectra of delta Sct stars corresponds to the rotational splitting. This is true independent of the stellar rotation rate. These promising results pave the way to finding a robust methodology to determine rotational splittings from the oscillation spectra of delta Sct stars and, thus, understanding the rotational profile of intermediate-mass pulsating stars. ; Plan Estatal de Investigacion Cientifica y Tecnica y de Innovacion ESP2017-87676-C5-5-R ; Programas Estatales de Generacion de Conocimiento y Fortalecimiento Cientifico y Tecnologico del Sistema de I+D+i y de I+D + i Orientada a los Retos de la Sociedad PID2019-107061GB-C63 ; State Agency for Research through the `Center of Excellence Severo Ochoa' SEV-2017-0709 ; Spanish Ministry of Science, Innovation and Universities ; Programa Estatal de Promocion del Talento y su Empleabilidad del Plan Estatal de Investigacion Cientifica y Tecnica y de Innovacion 2013-2016' of the Spanish Ministry of Science, Innovation and Universities PRE2018084322 ; Spanish Government ESP2017-87676-2-2 ; European Regional Development Fund/Junta de Andalucia-Consejeria de Economia y Conocimientoby Universidad de Granada E-FQM-041-UGR18 ; Spanish public funds for research PID2019-107061GB-C63 ESP201787676-2-2 ; Spanish Government RYC-2012-09913

Fractal fingerprints have been found recently in the light curves of several 5 Scuti stars observed by Convection Rotation and planetary Transits (CoRoT) satellite. This sole fact might pose a problem for the detection of pulsation frequencies using classical pre-whitening techniques, but it is also a potentially rich source for information about physical mechanisms associated with stellar variability. Assuming that a light curve is composed of a superposition of oscillation modes with a fractal background noise, in this work we applied the Coarse Graining Spectral Analysis (CGSA), a fast Fourier transform (FFT)-based algorithm, which can discriminate in a time series the stochastic fractal power spectra from the harmonic one. We have found that the fractal background component is determining the frequency content extracted using classical pre-whitening techniques in the light curves of 5 Scuti stars. This might be crucial to understand the amount of frequencies excited in these kinds of pulsating stars. Additionally, CGSA resulted to be relevant in order to extract the oscillation modes, this points to a new criterion to stop the pre-whitening cascade based on the percentage of fractal component in the residuals.© 2019 The Author(s). ; SdF, JP-G, JRR, ML-M, and RG acknowledge financial support from the State Agency for Research of the Spanish MCIU through the 'Center of Excellence Severn Ochoa' award for the Institute de Astrofisica de Andalucia (SEV-2017-0709). SdE, JP-G, JRR, ML-M, and RG acknowledge funding support from Spanish public funds for research under projects ESP2015-65712-C5-3-R. JCS and AGH acknowledge funding support from Spanish public funds for research under projects ESP2017-87676-2-2 and ESP2015-65712-C5-5-R. SdF, JP-G, and RG acknowledges support from the 'Junta de Andalucia' regional government under project 2012-P12-TIC-2469. JCS also acknowledges funding support from project RYC-2012-09913 under the 'Ramon y Cajal' program of the Spanish MINECO. ; Peer Reviewed

Open Access. Attribution 4.0 International (CC BY 4.0) ; This paper aims at being a provocative guide to the future of asteroseismology from the perspective of the analysis of time series, where the fundamentals of harmonic analysis are subjected to stress tests. In this context, we give an annotated summary of our research over the last decades on harmonic analysis of A-F stars. We discuss and explore the consequences of our findings, which may extend to any kind of pulsators. As well, we analyse the impact of this reconsideration on future asteroseismic studies, which would entail a paradigm shift. This includes a discussion on the presence of fractal behavior in delta Sct stars, and how this can be used to develop a stopping criterion of the pre-whitening process, as an alternative to SNR (or significance) criterion. Drilling a scientific paradigm has its natural resilience, hence the path described here is being arduous, although fruitful at the same time. ; SF, JP-G, JR, ML-M, and RG acknowledges financial support from the State Agency for Research of the Spanish MCIU through the Center of Excellence Severo Ochoa award for the Instituto de Astrofisica de Andalucia (SEV-2017-0709) and Spanish public funds for research under projects ESP2015-65712C5-5-R. JS and AG acknowledge funding support from Spanish public funds for research under projects ESP2017-87676-C5-2R. JS also acknowledges funding support from project RYC2012-09913 under the Ramon y Cajal program of the Spanish MINECO. AG acknowledges support from Universidad de Granada under project E-FQM-041-UGR18 from the Programa Operativo FEDER 2014-2020 programme by Junta de Andalucia regional Government. ; Peer reviewed

Context. It is known that the observed distribution of frequencies in CoRoT and Kepler δ Scuti stars has no parallelism with any theoretical model. Pre-whitening is a widespread technique in the analysis of time series with gaps from pulsating stars located in the classical instability strip, such as δ Scuti stars. However, some studies have pointed out that this technique might introduce biases in the results of the frequency analysis. Aims. This work aims at studying the biases that can result from pre-whitening in asteroseismology. The results will depend on the intrinsic range and distribution of frequencies of the stars. The periodic nature of the gaps in CoRoT observations, only in the range of the pulsational frequency content of the δ Scuti stars, is shown to be crucial to determining their oscillation frequencies, the first step in performing asteroseismology of these objects. Hence, here we focus on the impact of pre-whitening on the asteroseismic characterization of δ Scuti stars. Methods. We select a sample of 15 δ Scuti stars observed by the CoRoT satellite, for which ultra-high-quality photometric data have been obtained by its seismic channel. In order to study the impact on the asteroseismic characterization of δ Scuti stars we perform the pre-whitening procedure on three datasets: gapped data, linearly interpolated data, and data with gaps interpolated using Autoregressive and Moving Average models (ARMA). Results. The different results obtained show that at least in some cases pre-whitening is not an efficient procedure for the deconvolution of the spectral window. Therefore, in order to reduce the effect of the spectral window to a minimum, in addition to performing a pre-whitening of the data, it is necessary to interpolate with an algorithm that is aimed to preserve the original frequency content.© ESO 2018. ; JPG acknowledge support from the "Junta de Andalucía" local government under project 2012-P12-TIC-2469. JCS and AGH acknowledge funding support from Spanish public funds for research under project ESP2015-65712-C5-5-R (MINECO/FEDER), and from project RYC-2012-09913 under the "Ramón y Cajal" programme of the Spanish MINECO. JCS also acknowledge support by the European FP7 project "SPACEINN" (FP7-SPACE-2011-1). AM acknowledges support by the Spanish MINECO National Space Program through project ESP2015-65712-C5-1-R and "Ramon y Cajal" program RYC-2012-09913. This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 749962. ; Peer Reviewed

Detailed understanding of stellar physics is essential towards a robust determination of stellar properties (e.g. radius, mass, and age). Among the vital input physics used in the modelling of solar-type stars which remain poorly constrained, is the initial helium abundance. To this end, when constructing stellar model grids, the initial helium abundance is estimated either (i) by using the semi-empirical helium-to-heavy element enrichment ratio, (ΔY/ΔZ), anchored to the standard big bang nucleosynthesis value, or (ii) by setting the initial helium abundance as a free variable. Adopting 35 low-mass, solar-type stars with multiyear Kepler photometry from the asteroseismic 'LEGACY' sample, we explore the systematic uncertainties on the inferred stellar parameters (i.e. radius, mass, and age) arising from the treatment of the initial helium abundance in stellar model grids. The stellar masses and radii derived from grids with free initial helium abundance are lower compared to those from grids based on a fixed ΔY/ΔZ ratio. We find the systematic uncertainties on mean density, radius, mass, and age arising from grids which employ a fixed value of ΔY/ΔZ and those with free initial helium abundance to be ∼ 0.9 per cent, ∼ 2 per cent, ∼ 5 per cent, and ∼ 29 per cent, respectively. We report that the systematic uncertainties on the inferred masses and radii arising from the treatment of initial helium abundance in stellar grids lie within the expected accuracy limits of ESA's PLATO, although this is not the case for the age. © 2020 The Author(s). ; The authors acknowledge the dedicated team behind the NASA'S Kepler missions. BN thanks Verma Kuldeep, Achim Weiss, and the Stellar Evolution research group at Max-Planck-Institut fur Astrophysik (MPA) for the useful comments on this article. BN also acknowledges postdoctoral funding from the Alexander von Humboldt Foundation. AGH, JCS, and BN acknowledge funding support from Spanish public funds (including FEDER funds) for research under projects ESP2017-87676-C5-2-R and ESP2017-87676-C5-5-R. TLC acknowledges support from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 792848 (PULSATION). JF wishes to honor the memory of Johannes Andersen, recently passed way. JF acknowledges funding from POCH and Portuguese FCT grant SFRH/BSAB/143060/2018. CITEUC is funded by National Funds through FCT - Foundation for Science and Technology (projects UID-PB/00611/2020). MSC is supported by national funds through Fundacao para a Ciencia e a Tecnologia (FCT, Portugal) - in the form of a work contract and through the research grants UIDB/04434/2020, UIDP/04434/2020, and PTDC/FIS-AST/30389/2017, and by FEDER -Fundo Europeu de Desenvolvimento Regional through COMPETE2020 Programa Operacional Competitividade e Internacionalizacao (grant: POCI-01-0145-FEDER-030389). AGH also acknowledges support from 'FEDER/Junta de Andalucia-Consejeria de Economia y Conocimiento' under project E-FQM-041-UGR18 by Universidad de Granada. JCS also acknowledges support from project RYC-2012-09913 under the 'Ramon y Cajal' program of the Spanish Ministry of Science and Education. JC is funded by the Fundamental Research Funds for the Central Universities (grant: 19lgpy278). BA acknowledges support from the FCT PhD programme PD/BD/135226/2017. We thank the reviewer for the constructive remarks.

Detailed understanding of stellar physics is essential towards a robust determination of stellar properties (e.g. radius, mass, and age). Among the vital input physics used in the modelling of solar-type stars which remain poorly constrained, is the initial helium abundance. To this end, when constructing stellar model grids, the initial helium abundance is estimated either (i) by using the semi-empirical helium-to-heavy element enrichment ratio, (ΔY/ΔZ), anchored to the standard big bang nucleosynthesis value, or (ii) by setting the initial helium abundance as a free variable. Adopting 35 low-mass, solar-type stars with multiyear Kepler photometry from the asteroseismic 'LEGACY' sample, we explore the systematic uncertainties on the inferred stellar parameters (i.e. radius, mass, and age) arising from the treatment of the initial helium abundance in stellar model grids. The stellar masses and radii derived from grids with free initial helium abundance are lower compared to those from grids based on a fixed ΔY/ΔZ ratio. We find the systematic uncertainties on mean density, radius, mass, and age arising from grids which employ a fixed value of ΔY/ΔZ and those with free initial helium abundance to be ∼ 0.9 per cent, ∼ 2 per cent, ∼ 5 per cent, and ∼ 29 per cent, respectively. We report that the systematic uncertainties on the inferred masses and radii arising from the treatment of initial helium abundance in stellar grids lie within the expected accuracy limits of ESA's PLATO, although this is not the case for the age. © 2020 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society ; The authors acknowledge the dedicated team behind the NASA'S Kepler missions. BN thanks Verma Kuldeep, Achim Weiss, and the Stellar Evolution research group at Max-Planck-Institut fur Astrophysik (MPA) for the useful comments on this article. BN also acknowledges postdoctoral funding from the Alexander von Humboldt Foundation. AGH, JCS, and BN acknowledge funding support from Spanish public funds (including FEDER funds) for research under projects ESP2017-87676-C5-2-R and ESP2017-87676-C5-5-R. TLC acknowledges support from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 792848 (PULSATION). JF wishes to honor the memory of Johannes Andersen, recently passed way. JF acknowledges funding from POCH and Portuguese FCT grant SFRH/BSAB/143060/2018. CITEUC is funded by National Funds through FCT - Foundation for Science and Technology (projects UID-PB/00611/2020). MSC is supported by national funds through Fundacao para a Ciencia e a Tecnologia (FCT, Portugal) - in the form of a work contract and through the research grants UIDB/04434/2020, UIDP/04434/2020, and PTDC/FIS-AST/30389/2017, and by FEDER -Fundo Europeu de Desenvolvimento Regional through COMPETE2020 Programa Operacional Competitividade e Internacionalizacao (grant: POCI-01-0145-FEDER-030389). AGH also acknowledges support from 'FEDER/Junta de Andalucia-Consejeria de Economia y Conocimiento' under project E-FQM-041-UGR18 by Universidad de Granada. JCS also acknowledges support from project RYC-2012-09913 under the 'Ramon y Cajal' program of the Spanish Ministry of Science and Education. JC is funded by the Fundamental Research Funds for the Central Universities (grant: 19lgpy278). BA acknowledges support from the FCT PhD programme PD/BD/135226/2017. We thank the reviewer for the constructive remarks. ; With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709. ; Peer reviewed

We present the first results from the Transiting Exoplanet Survey Satellite (TESS) on the rotational and pulsational variability of magnetic chemically peculiar A-type stars. We analyse TESS 2-min cadence data from sectors 1 and 2 on a sample of 83 stars. Five new rapidly oscillating Ap (roAp) stars are announced. One of these pulsates with periods around 4.7 min, making it the shortest period roAp star known to date. Four out of the five new roAp stars are multiperiodic. Three of these and the singly periodic one show the presence of rotational mode splitting. Individual frequencies are provided in all cases. In addition, seven previously known roAp stars are analysed. Additional modes of oscillation are found in some stars, while in others we are able to distinguish the true pulsations from possible aliases present in the ground-based data. We find that the pulsation amplitude in the TESS filter is typically a factor of 6 smaller than that in the B filter, which is usually used for ground-based observations. For four roAp stars we set constraints on the inclination angle and magnetic obliquity, through the application of the oblique pulsator model. We also confirm the absence of roAp-type pulsations down to amplitude limits of 6 and 13 \mumag, respectively, in two of the best characterized non-oscillating Ap (noAp) stars. We announce 27 new rotational variables along with their rotation periods, and provide different rotation periods for seven other stars. Finally, we discuss how these results challenge state-of-the-art pulsation models for roAp stars.© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. ; This work was supported by FCT - Fundacao para a Ciencia e a Tecnologia through national funds and by FEDER through COMPETE02020 - Programa Operacional Competitividade e Internacionalizacao by these grants: UID/FIS/04434/2019, PTDC/FIS-AST/30389/2017 & POCI-01-0145-FEDER-030389. MC is supported in the form of work contract funded by national funds through FCT. Funding for the Stellar Astrophysics Centre is provided by The Danish National Research Foundation (Grant agreement no.: DNRF106). DLH and DWK acknowledge financial support from the Science and Technology Facilities Council (STFC) via grant ST/M000877/1. This work has made use of data from the European Space Agency (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. LFM acknowledges support from the UNAM by the way of DGAPA project PAPIIT IN100918. The research leading to these results has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No670519: MAMSIE) and from the Fonds Wetenschappelijk Onderzoek -Vlaanderen (FWO) under the grant agreement G0H5416N (ERC Opvangproject). MS acknowledges the financial support of Postdoc@MUNI project CZ.02.2.69/0.0/0.0/16 027/0008360. EN acknowledges the Polish National Science Center grants no. 2014/13/B/ST9/00902. JCS acknowledges funding support from Spanish public funds for research under projects ESP2017-87676-2-2 and ESP2015-65712-C5-5-R, and from project RYC-2012-09913 under the 'Ramon y Cajal' program of the Spanish Ministry of Science and Education. AGH acknowledges funding support from Spanish public funds for research under projects ESP2017-87676-2-2 and ESP2015-65712-C5-5-R of the Spanish Ministry of Science and Education. AS, ZsB, and RSz acknowledge the financial support of the GINOP-2.3.2-15-2016-00003, K-115709, K-113117, K-119517, and PD-123910 grants of the Hungarian National Research, Development and Innovation Office (NKFIH), and the Lendulet Program of the Hungarian Academy of Sciences, project No. LP2018-7/2018. GH has been supported by the Polish NCN grant 2015/18/A/ST9/00578. MLM acknowledges funding support from Spanish public funds for research under project ESP2015-65712-C5-3-R. JPG acknowledges funding support from Spanish public funds for research under project ESP2017-87676-C5-5-R. MLM and JPG also acknowledges funding support from the State Agency for Research of the Spanish MCIU through the 'Center of Excellence Severo Ochoa' award for the Institute de Astrofisica de Andalucia (SEV-2017-0709). IS acknowledges funding support of NSF under projects DN 08-1/2016 and DN 18/13-12.12.2017. P. Kolaczek-Szymanski acknowledges support from the NCN grant no. 2016/21/B/ST9/01126. This paper includes data collected by the TESS mission. Funding for the TESS mission is provided by the NASA Explorer Program. ; Peer Reviewed

We present the first asteroseismic results for δ Scuti and γ Doradus stars observed in Sectors 1 and 2 of the TESS mission. We utilize the 2-min cadence TESS data for a sample of 117 stars to classify their behaviour regarding variability and place them in the Hertzsprung-Russell diagram using Gaia DR2 data. Included within our sample are the eponymous members of two pulsator classes, γ Doradus and SX Phoenicis. Our sample of pulsating intermediate-mass stars observed by TESS also allows us to confront theoretical models of pulsation driving in the classical instability strip for the first time and show that mixing processes in the outer envelope play an important role. We derive an empirical estimate of 74 per cent for the relative amplitude suppression factor as a result of the redder TESS passband compared to the Kepler mission using a pulsating eclipsing binary system. Furthermore, our sample contains many high-frequency pulsators, allowing us to probe the frequency variability of hot young δ Scuti stars, which were lacking in the Kepler mission data set, and identify promising targets for future asteroseismic modelling. The TESS data also allow us to refine the stellar parameters of SX Phoenicis, which is believed to be a blue straggler. © 2019 The Author(s) ; We thank the referee for useful comments and discussions. 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 Re-search Foundation (Grant agreement no.: DNRF106), ESA PRODEX (PEA 4000119301), and Stellar Astrophysics Centre (SAC) at Aarhus University. We thank the TESS and TASC/TASOC teams for their support of this work. This research has made use of the SIMBAD data base, operated at CDS, Strasbourg, France. Some of the data presented in this paper were obtained from the Mikulski Archive for Space Telescopes (MAST). STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-2655. Funding for the Stellar Astrophysics Centre is provided by The Danish National Research Foundation (Grant agreement no.: DNRF106). MC 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, PTDC/FIS-AST/30389/2017, and POCI-01-0145-FEDER-030389. MC is supported in the form of work contract funded by national funds through FCT (CEECIND/02619/2017). JDD acknowledges support from the Polish National Science Center (NCN), grant no. 2018/29/B/ST9/02803. AGH acknowledges funding support from Spanish public funds for research under projects ESP201787676-2-2 and ESP2015-65712-C5-5-R of the Spanish Ministry of Science and Education. FKA gratefully acknowledges funding through grant 2015/18/A/ST9/00578 of the Polish National Science Centre (NCN). JPe acknowledges funding support from the NSF REU program under grant number PHY-1359195. APi and KK acknowledge support provided by the Polish National Science Center (NCN) grant No. 2016/21/B/ST9/01126. This project has been supported by the Lendulet Program of the Hungarian Academy of Sciences, project No. LP2018-7/2018, and by the support provided from the National Research, Development and Innovation Fund of Hungary, financed under the K16 funding scheme, project No. 115709. JCS acknowledges funding support from Spanish public funds for research under projects ESP2017-87676-2-2 and ESP2015-65712-C5-5-R, and from project RYC2012-09913 under the 'Ramon y Cajal' program of the Spanish Ministry of Science and Education. The research leading to these results has (partially) received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement N.670519: MAMSIE), from the KULeuven Research Council (grant C16/18/005: PARADISE), from the Research Foundation Flanders (FWO) under grant agreement G0H5416N (ERC Runner Up Project), as well as from the BELgian federal Science Policy Office (BELSPO) through PRODEX grant PLATO. SBF acknowledges support by the Spanish State Research Agency (AEI) through project No. 'ESP2017-87676-C5-1-R' and No MDM-2017-0737 Unidad de Excelencia `Maria de Maeztu'-Centro de Astrobiolog ' ia (CSICINTA). ZsB acknowledges the support provided from the National Research, Development and Innovation Fund of Hungary, financed under the PD1717 funding scheme, project no. PD-123910. DLB acknowledges support from the Whitaker Foundation. SC gratefully acknowledges funding through grant 2015/18/A/ST9/00578 of the Polish National Science Centre (NCN). CCL gratefully acknowledges support from the Natural Sciences and Engineering Research Council of Canada. GMM acknowledges funding by the STFC consolidated grant ST/R000603/1. RMO, SC, and DR were supported in this work by the 'Programme National de Physique Stellaire' (PNPS) of CNRS/INSU co-funded by CEA and CNES. IS acknowledges the partial support of projects DN 08-1/2016 and DN 18/13-12.12.2017. PS acknowledges financial support by the Polish NCN grant 2015/18/A/ST9/00578. MS acknowledges the Postdoc@MUNI project CZ.02.2.69/0.0/0.0/16-027/0008360. JPG, JRR, and MLM acknowledge funding support from Spanish public funds for research under project ESP2017-87676-C5-5-R and from the State Agency for Research of the Spanish MCIU through the 'Center of Excellence Severo Ochoa' award for the Instituto de Astrofisica de Andalucia (SEV-2017-0709). JAE acknowledges STFC for funding support (reference ST/N504348/1). LFM acknowledges the financial support from the DGAPA-UNAM under grant PAPIIT IN100918. DMk acknowledges his work as part of the research activity of the National Astronomical Research Institute of Thailand (NARIT), which is supported by the Ministry of Science and Technology of Thailand. MR acknowledges the support of the French Agence Nationale de la Recherche (ANR), under grant ESRR (ANR-16-CE31-0007-01). We acknowledge the International Space Science Institute (ISSI) for supporting the SoFAR international team http://www.issi.unibe.ch/teams/sofar/.TW acknowledges the NSFC of China (Grant Nos. 11873084 and 11521303) and YunnanApplied Basic Research Projects (GrantNo. 2017B008). IS acknowledges for a partial support of DN 08-1/2016 funded by the Bulgarian NSF. This work hasmade use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, ht tps://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. The research leading to these results has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No. 670519: MAMSIE) and from the Fonds Wetenschappelijk Onderzoek - Vlaanderen (FWO) under the grant agreement G0H5416N (ERC Opvangproject). This research has made use of the VizieR catalogue access tool, CDS, Strasbourg, France (DOI:10.26093/cds/vizier). The original description of the VizieR service was published in A&AS 143, 23. This publication makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation.