Description
Made available in DSpace on 2021-06-25T11:08:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-12-01
Context. Trans-Neptunian objects (TNOs) and Centaurs are remnants of our planetary system formation, and their physical properties have invaluable information for evolutionary theories. Stellar occultation is a ground-based method for studying these distant small bodies and has presented exciting results. These observations can provide precise profiles of the involved body, allowing an accurate determination of its size and shape. Aims. The goal is to show that even single-chord detections of TNOs allow us to measure their milliarcsecond astrometric positions in the reference frame of the Gaia second data release (DR2). Accurate ephemerides can then be generated, allowing predictions of stellar occultations with much higher reliability. Methods. We analyzed data from various stellar occultation detections to obtain astrometric positions of the involved bodies. The events published before the Gaia era were updated so that the Gaia DR2 stellar catalog is the reference, thus providing accurate positions. Events with detection from one or two different sites (single or double chord) were analyzed to determine the event duration. Previously determined sizes were used to calculate the position of the object center and its corresponding error with respectto the detected chord and the International Celestial Reference System propagated Gaia DR2 star position. Results. We derive 37 precise astrometric positions for 19 TNOs and four Centaurs. Twenty-one of these events are presented here for the first time. Although about 68% of our results are based on single-chord detection, most have intrinsic precision at the submilliarcsecond level. Lower limits on the diameter of bodies such as Sedna, 2002 KX14, and Echeclus, and also shape constraints on 2002 VE95, 2003 FF128, and 2005 TV189 are presented as valuable byproducts. Conclusions. Using the Gaia DR2 catalog, we show that even a single detection of a stellar occultation allows improving the object ephemeris significantly, which in turn enables predicting a future stellar occultation with high accuracy. Observational campaigns can be efficiently organized with this help, and may provide a full physical characterization of the involved object, or even the study of topographic features such as satellites or rings.
Observatório Nacional/MCTIC Bairro Imperial de São Cristóvão, R. General José Cristino 77
Federal University of Technology-Paraná (UTFPR/DAFIS), Rua Sete de Setembro
Laboratório Interinstitucional de E-Astronomia-LIneA and Inct Do E-Universo Bairro Imperial de São Cristóvão, Rua Gal. José Cristino 77
Institut Polytechnique des Sciences Avancées Ipsa, 63 boulevard de Brandebourg
Institut de Mécanique Céleste et de Calcul des Éphémérides Imcce Observatoire de Paris Psl Research University Cnrs Sorbonne Universités Upmc Univ Paris 06 Univ. Lille, 77, Av. Denfert-Rochereau
Instituto de Astrofísica de Andalucía IAA-CSIC, Glorieta de la Astronomía s/n
Lesia Observatoire de Paris Université Psl Cnrs Sorbonne Université Univ. Paris Diderot Sorbonne Paris Cité, 5 place Jules Janssen
Observatório Do Valongo/UFRJ, Ladeira Pedro Antônio 43
Florida Space Institute University of Central Florida, 12354 Research Parkway
UNESP-São Paulo State University Grupo de Dinâmica Orbital e Planetologia
International Occultation Timing Association (IOTA), P.O. Box 423
Trans-Tasman Occultation Alliance (TTOA), PO Box 3181
Canberra Astronomical Society
Samford Valley Observatory (Q79)
Coral Towers Observatory
Centre of Studies and Activities for Space (CISAS) 'G. Colombo' University of Padova, Via Venezia 15
INAF-Astronomical Observatory of Padova, Vicolo dell'Osservatorio 5
Jewel Box Observatory, 69 Falcon St
Sonear Observatory
Department of Physics and Astronomy 'G. Galilei' University of Padova, Via F. Marzolo 8
Mount John University Observatory University of Canterbury, PO Box 56
Astronomical Institute Academy of Sciences of the Czech Republic, Fričova 298
Astronomical Association of Queensland, 5 Curtis Street
Aix Marseille Univ Cnrs Cnes Lam
SOTAS-Stellar Occultation Timing Association Switzerland Swiss Astronomical Society
Konkoly Observatory Research Centre for Astronomy and Earth Sciences, Konkoly-Thege Miklós út 15-17
Eötvös Loránd University Department of Astronomy, Pázmány Péter sétány 1/A
Elte Eötvös Loránd University Institute of Physics, Pázmány Péter sétány 1/A
Centro de Amigos de la Astronomia Reconquista-CAAR
Japan Occultation Information Network (JOIN)
Reedy Creek Observatory
Star Institute Université de Liège, Allée du 6 août, 19C
Astronomical Institute Slovak Academy of Sciences
Astronomical Observatory Institute Faculty of Physics Adam Mickiewicz University
San Pedro de Atacama Celestial Explorations-SPACE
University of Ljubljana Faculty of Mathematics and Physics, Jadranska 19
Panamanian Observatory in San Pedro de Atacama-OPSPA
Department of Physics Sharif University of Technology, PO Box 11155-9161
Institute for Astronomy University of Edinburgh Royal Observatory
Club d'Astronomie Luberon Sud Astro
Centro de Astronomía (CITEVA) Universidad de Antofagasta, Avenida U. de Antofagasta
UNESP-São Paulo State University Grupo de Dinâmica Orbital e Planetologia
