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Full list of authors: Santos-Sanz, P.; Ortiz, J. L.; Sicardy, B.; Popescu, M.; Benedetti-Rossi, G.; Morales, N.; Vara-Lubiano, M.; Camargo, J. I. B.; Pereira, C. L.; Rommel, F. L.; Assafin, M.; Desmars, J.; Braga-Ribas, F.; Duffard, R.; Marques Oliveira, J.; Vieira-Martins, R.; Fernández-Valenzuela, E.; Morgado, B. E.; Acar, M.; Anghel, S.; Atalay, E.; Ateş, A.; Bakiş, H.; Bakis, V.; Eker, Z.; Erece, O.; Kaspi, S.; Kayhan, C.; Kilic, S. E.; Kilic, Y.; Manulis, I.; Nedelcu, D. A.; Niaei, M. S.; Nir, G.; Ofek, E.; Ozisik, T.; Petrescu, E.; Satir, O.; Solmaz, A.; Sonka, A.; Tekes, M.; Unsalan, O.; Yesilyaprak, C.; Anghel, R.; Berteşteanu, D.; Curelaru, L.; Danescu, C.; Dumitrescu, V.; Gherase, R.; Hudin, L.; Stoian, A. -M.; Tercu, J. O.; Truta, R.; Turcu, V.; Vantdevara, C.; Belskaya, I.; Dementiev, T. O.; Gazeas, K.; Karampotsiou, S.; Kashuba, V.; Kiss, Cs.; Koshkin, N.; Kozhukhov, O. M.; Krugly, Y.; Lecacheux, J.; Pal, A.; Püsküllü, Ç.; Szakats, R.; Zhukov, V.; Bamberger, D.; Mondon, B.; Perelló, C.; Pratt, A.; Schnabel, C.; Selva, A.; Teng, J. P.; Tigani, K.; Tsamis, V.; Weber, C.; Wells, G.; Kalkan, S.; Kudak, V.; Marciniak, A.; Ogloza, W.; Özdemir, T.; Pakštiene, E.; Perig, V.; Żejmo, M.--This is an Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited., Context. As part of our international program aimed at obtaining accurate physical properties of trans-Neptunian objects (TNOs), we predicted a stellar occultation by the TNO (38628) Huya of the star Gaia DR2 4352760586390566400 (mG = 11.5 mag) on March 18, 2019. After an extensive observational campaign geared at obtaining the astrometric data, we updated the prediction and found it favorable to central Europe. Therefore, we mobilized half a hundred of professional and amateur astronomers in this region and the occultation was finally detected by 21 telescopes located at 18 sites in Europe and Asia. This places the Huya event among the best ever observed stellar occultation by a TNO in terms of the number of chords. Aims. The aim of our work is to determine an accurate size, shape, and geometric albedo for the TNO (38628) Huya by using the observations obtained from a multi-chord stellar occultation. We also aim to provide constraints on the density and other internal properties of this TNO. Methods. The 21 positive detections of the occultation by Huya allowed us to obtain well-separated chords which permitted us to fit an ellipse for the limb of the body at the moment of the occultation (i.e., the instantaneous limb) with kilometric accuracy. Results. The projected semi-major and minor axes of the best ellipse fit obtained using the occultation data are (a′, b′) = (217.6 ± 3.5 km, 194.1 ± 6.1 km) with a position angle for the minor axis of P′ = 55.2° ± 9.1. From this fit, the projected area-equivalent diameter is 411.0 ± 7.3 km. This diameter is compatible with the equivalent diameter for Huya obtained from radiometric techniques (D = 406 ± 16 km). From this instantaneous limb, we obtained the geometric albedo for Huya (pV = 0.079 ± 0.004) and we explored possible three-dimensional shapes and constraints to the mass density for this TNO. We did not detect the satellite of Huya through this occultation, but the presence of rings or debris around Huya was constrained using the occultation data. We also derived an upper limit for a putative Pluto-like global atmosphere of about psurf = 10 nbar. © P. Santos-Sanz et al. 2022., P.S-S. acknowledges financial support by the Spanish grant AYA-RTI2018-098657-J-I00 “LEO-SBNAF” (MCIU/AEI/FEDER, UE). P.S-S., J.L.O., N.M., M.V-L. and R.D. acknowledge financial 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), they also acknowledge the financial support by the Spanish grants AYA-2017-84637-R and PID2020-112789GB-I00, and the Proyectos de Excelencia de la Junta de Andalucía 2012-FQM1776 and PY20-01309. The research leading to these results has received funding from the European Union’s Horizon 2020 Research and Innovation Programme, under Grant Agreement no. 687378, as part of the project “Small Bodies Near and Far” (SBNAF). Part of the research leading to these results has received funding from the European Research Council under the European Community’s H2020 (2014-2020/ERC Grant Agreement no. 669416 “LUCKY STAR”). Part of the work of M.P. was financed by a grant of the Romanian National Authority for Scientific Research and Innovation, CNCS – UEFISCDI PN-III-P1-1.1-TE-2019-1504. This study was financed in part by the Coordenaçâo de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001 and the National Institute of Science and Technology of the e-Universe project (INCT do e-Universo, CNPq grant 465376/2014-2). The following authors acknowledge the respective CNPq grants: F.B-R 309578/2017-5; R.V.-M. 304544/2017-5, 401903/2016-8; J.I.B.C. 308150/2016-3 and 305917/2019-6; M.A 427700/2018-3, 310683/2017-3 and 473002/2013-2; B.E.M. 150612/2020-6. G.B.R. thanks the support of CAPES and FAPERJ/PAPDRJ (E26/203.173/2016) grant. J.M.O. acknowledges financial support from the Portuguese Foundation for Science and Technology (FCT) and the European Social Fund (ESF) through the PhD grant SFRH/BD/131700/2017. E.F-V. acknowledges funding through the Preeminant Postdoctoral Program of the University of Central Florida. C.K., A.P. and R.S. have been supported by the grants K-125015 and K-138962 of the National Research, Development and Innovation Office (NKFIH, Hungary). E.P. acknowledges the Europlanet 2024 RI project funded by the European Union’s Horizon 2020 Research and Innovation Programme (Grant agreement No. 871149). We are grateful to the CAHA and OSN staffs. This research is partially based on observations collected at the Centro Astronómico Hispano Alemán (CAHA) at Calar Alto, operated jointly by Junta de Andalucía and Consejo Superior de Investigaciones Científicas (IAA-CSIC). This research was also partially based on observation carried out at the Observatorio de Sierra Nevada (OSN) operated by Instituto de Astrofísica de Andalucía (CSIC). This article is also based on observations made in the Observatorios de Canarias del IAC with the Liverpool Telescope operated on the island of La Palma by the Instituto de Astrofísica de Canarias in the Observatorio del Roque de los Muchachos. Part of the results were based on observations taken at Pico dos Dias Observatory of the National Laboratory of Astrophysics (LNA/Brazil). Part of the data were collected during the photometric monitoring observations with the robotic and remotely controlled observatory at the University of Athens Observatory – UOAO (Gazeas 2016). We thank the Adiyaman University Astrophysics Application and Research Center for their support in the acquisition of data with the ADYU60 telescope. 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.

This article is dedicated to the memory of H.-J. Bode, J. G. Greenhill and O. Faragó for their long-standing support and participation to occultation campaigns. The work leading to these results has received funding from the European Research Council under the European Community’s H2020 2014-2020 ERC Grant Agreement n° 669416 “Lucky Star”. E.M. thanks support from Concytec-Fondecyt-PE and GA, FC-UNI for providing support during the 2012 July 18 occultation. B.S. thanks S. Para for partly supporting this research though a donation, J. P. Beaulieu for helping us accessing to the Hobart Observatory facilities and B. Warner, B. L. Gary, C. Erickson, H. Reitsema, L. Albert, P. J. Merritt, T. Hall, W. J. Romanishin, Y. J. Choi for providing data during the 2007 March 18 occultation. M.A. thanks CNPq (Grants 427700/2018-3, 310683/2017-3 and 473002/2013-2) and FAPERJ (Grant E-26/111.488/2013). J.L.O. thanks support from grant AYA2017-89637-R. P.S.S. acknowledges financial support from the European Union’s Horizon 2020 Research and Innovation Programme, under Grant Agreement no 687378, as part of the project “Small Bodies Near and Far” (SBNAF). J.L.O., R.D., P.S.S. and N.M. acknowledge financial 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). F.B.R. acknowledges CNPq support process 309578/2017-5. G.B.R. thanks support from the grant CAPES-FAPERJ/PAPDRJ (E26/203.173/2016). J.I.B.C. acknowledges CNPq grant 308150/2016-3. R.V.M. thanks the grants: CNPq-304544/2017-5, 401903/2016-8, and Faperj: PAPDRJ-45/2013 and E-26/203.026/2015. B.M. thanks the CAPES/Cofecub-394/2016-05 grant and CAPES/Brazil – Finance Code 001. B.M. and A.R.G.J. were financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) – Finance Code 001. TRAPPIST-North is a project funded by the University of Liège, in collaboration with Cadi Ayyad University of Marrakech (Morocco). TRAPPIST-South is a project funded by the Belgian Fonds (National) de la Recherche Scientifique (F.R.S.-FNRS) under grant FRFC 2.5.594.09.F, with the participation of the Swiss National Science Foundation (FNS/SNSF). VSD, SPL, TRM and ULTRACAM are all supported by the STFC. K.G. acknowledges help from the team of Archenhold-Observatory, Berlin, and A.R. thanks G. Román (Granada) for help during the observation of the 2016 July 19 occultation. A.J.C.T. acknowledges support from the Spanish Ministry Project AYA2015-71718-R (including EU funds). We thank Caisey Harlingten for the repeated use of his 50 cm telescopes in San Pedro de Atacama, Chile. We thank the Italian Telescopio Nazionale Galileo (TNG), operated on the island of La Palma by the Fundación Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias. L.M. acknowledges support from the Italian Minister of Instruction, University and Research (MIUR) through FFABR 2017 fund and support from the University of Rome Tor Vergata through “Mission: Sustainability 2016” fund. The Astronomical Observatory of the Autonomous Region of the Aosta Valley (OAVdA) is managed by the Fondazione Clément Fillietroz-ONLUS, which is supported by the Regional Governmentof the Aosta Valley, the Town Municipality of Nus and the “Unité des Communes valdôtaines Mont-Émilius”. The research was partially funded by a 2016 “Research and Education”s grant from Fondazione CRT. We thank D.P. Hinson for his constructive and detailed comments that helped to improve this article., Context. The tenuous nitrogen (N2) atmosphere on Pluto undergoes strong seasonal effects due to high obliquity and orbital eccentricity, and has recently (July 2015) been observed by the New Horizons spacecraft. Aims. The main goals of this study are (i) to construct a well calibrated record of the seasonal evolution of surface pressure on Pluto and (ii) to constrain the structure of the lower atmosphere using a central flash observed in 2015. Methods. Eleven stellar occultations by Pluto observed between 2002 and 2016 are used to retrieve atmospheric profiles (density, pressure, temperature) between altitude levels of ~5 and ~380 km (i.e. pressures from ~ 10 μbar to 10 nbar). Results. (i) Pressure has suffered a monotonic increase from 1988 to 2016, that is compared to a seasonal volatile transport model, from which tight constraints on a combination of albedo and emissivity of N2 ice are derived. (ii) A central flash observed on 2015 June 29 is consistent with New Horizons REX profiles, provided that (a) large diurnal temperature variations (not expected by current models) occur over Sputnik Planitia; and/or (b) hazes with tangential optical depth of ~0.3 are present at 4–7 km altitude levels; and/or (c) the nominal REX density values are overestimated by an implausibly large factor of ~20%; and/or (d) higher terrains block part of the flash in the Charon facing hemisphere., European Research Council under the European Community’s H2020 2014-2020 ERC Grant Agreement n° 669416 “Lucky Star”, Grants 427700/2018-3, 310683/2017-3 and 473002/2013-2) and FAPERJ (Grant E-26/111.488/2013), Grant AYA2017-89637-R. P.S.S. acknowledges financial support from the European Union’s Horizon 2020 Research and Innovation Programme, under Grant Agreement no 687378, as part of the project “Small Bodies Near and Far” (SBNAF), Financial 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), Support process 309578/2017-5. G.B.R. thanks support from the grant CAPES-FAPERJ/PAPDRJ (E26/203.173/2016). J.I.B.C. acknowledges CNPq grant 308150/2016-3. R.V.M. thanks the grants: CNPq-304544/2017-5, 401903/2016-8, and Faperj: PAPDRJ-45/2013 and E-26/203.026/2015. B.M. thanks the CAPES/Cofecub-394/2016-05 grant and CAPES/Brazil – Finance Code 001., Grant FRFC 2.5.594.09.F, with the participation of the Swiss National Science Foundation (FNS/SNSF), Support from the Spanish Ministry Project AYA2015-71718-R (including EU funds), Support from the Italian Minister of Instruction, University and Research (MIUR) through FFABR 2017 fund and support from the University of Rome Tor Vergata through “Mission: Sustainability 2016” fund

Context. In 2009, the Sun and the Earth passed through the equatorial plane of Jupiter and therefore the orbital planes of its main satellites. It was the equinox on Jupiter. This occurrence made mutual occultations and eclipses between the satellites possible. Experience has shown that the observations of such events provide accurate astrometric data able to bring new information on the dynamics of the Galilean satellites. Observations are made under the form of photometric measurements, but need to be made through the organization of a worldwide observation campaign maximizing the number and the quality of the data obtained. Aims. This work focuses on processing the complete database of photometric observations of the mutual occultations and eclipses of the Galilean satellites of Jupiter made during the international campaign in 2009. The final goal is to derive new accurate astrometric data. Methods. We used an accurate photometric model of mutual events adequate with the accuracy of the observation. Our original method was applied to derive astrometric data from photometric observations of mutual occultations and eclipses of the Galilean satellites of Jupiter. Results. We processed the 457 lightcurves obtained during the international campaign of photometric observations of the Galilean satellites of Jupiter in 2009. Compared with the theory, for successful observations, the r.m.s. of O-C residuals are equal to 45.8 mas and 81.1 mas in right ascension and declination, respectively; the mean O-C residuals are equal to -2 mas and -9 mas in right ascension and declination, respectively, for mutual occultations; and -6 mas and +1 mas in right ascension and declination, respectively, for mutual eclipses. © ESO, 2014. Arlot J.-E. 1 Emelyanov N. 2 1 Varfolomeev M. I. 2 Amossé A. 3 Arena C. 4 Assafin M. 40 Barbieri L. 5 Bolzoni S. 6 Bragas-Ribas F. 54 Camargo J. I. B. 54 Casarramona F. 8 Casas R. 37 Christou A. 9 Colas F. 1 Collard A. 3 Combe S. 10 Constantinescu M. 11 Dangl G. 12 De Cat P. 34 Degenhardt S. 13 Delcroix M. 14 Dias-Oliveira A. 54 Dourneau G. 15 57 Douvris A. 16 Druon C. 3 Ellington C. K. 17 Estraviz G. 8 Farissier P. 10 Farmakopoulos A. 16 Garlitz J. 18 Gault D. 19 George T. 20 Gorda S. Yu. 42 Grismore J. 21 Guo D. F. 22 Herald D. 56 Ida M. 23 Ishida M. 23 Ivanov A. V. 24 Klemt B. 7 Koshkin N. 25 Le Campion J. F. 15 57 Liakos A. 26 Liao S. L. 27 Li S. N. 27 Loader B. 28 Lopresti C. 29 Lo Savio E. 4 Marchini A. 30 Marino G. 4 Masi G. 53 Massallé A. 8 Maulella R. 29 McFarland J. 9 Miyashita K. 32 Napoli C. 4 Noyelles B. 33 1 3 Pauwels T. 34 Pavlov H. 35 Peng Q. Y. 36 Perelló C. 8 Priban V. 38 Prost J. 39 Razemon S. 3 Rousselle J. P. 3 ⋆ Rovira J. 8 Ruisi R. 41 Ruocco N. 31 Salvaggio F. 4 Sbarufatti G. 43 Shakun L. 25 Scheck A. 44 Sciuto C. 4 da Silva Neto D. N. 55 V Sinyaeva N. 45 Sofia A. 4 Sonka A. 11 Talbot J. 46 Tang Z. H. 27 Tejfel V. G. 45 Thuillot W. 1 Tigani K. 16 Timerson B. 47 Tontodonati E. 48 Tsamis V. 16 Unwin M. 49 Venable R. 50 Vieira-Martins R. 54 1 40 Vilar J. 51 Vingerhoets P. 34 Watanabe H. 52 Yin H. X. 22 Yu Y. 27 Zambelli R. 29 1 Institut de mécanique céleste et de calcul des éphémérides-Observatoire de Paris, UMR 8028 CNRS, UPMC, USTL , 77 avenue Denfert-Rochereau , 75014 Paris , France 2 Sternberg Astronomical Institute, Lomonosov Moscow State University , 119991 Moscow , Russia 3 Association Jonckheere-Les Amis de l’Observatoire de Lille, 1 Impasse de l’Observatoire , 59000 Lille , France 4 Gruppo Astrofili Catanesi , 95128 Catania , Italy 5 Associazione Astrofili Bolognesi , 95128 Bologna , Italy 6 viale L.Pirandello, 26 , 21052 Busto Arsizio (VA) , Italy 7 Im Erlenhof 2a , 51429 Bergisch Gladbach , Germany 8 Agrupació Astronómica de Sabadell, Carrer Prat de la Riba, s/n, 08206 Sabadell , Catalonia , Spain 9 Armagh Observatory , College Hill , Armagh BT61 9DG , UK 10 CALA, Place de la nation , 69120 Vaulx-en-Velin , France 11 Observatorul Astronomic Amiral Vasile Urseanu , no.21, Lascar Catargiu Boulevard , 71111 Bucharest , Romania 12 Nonndorf 12 , 3830 , Austria 13 2112 Maple Leaf Trail , Columbia , TN , 38401 , USA 14 2 rue de l’Ardèche , 31170 Tournefeuille , France 15 Univ. Bordeaux, LAB, UMR 5804 , 33270 Floirac , France 16 Astronomical Union of Sparta , 23100 Sparta , Greece 17 Plantation, FL , USA 18 1155 Hartford St Elgin , Oregon 97827 , USA 19 22 Booker Road , Hawkesbury Heights NSW 2777 , Australia 20 136 Rio Senda , Umatilla , Oregon 97882 , USA 21 Bartlesville , Oklahoma , USA 22 Shandong University at Weihai , 264209 Weihai , PR China 23 1-4-17, Okino, Higashi-Ohmi , 527-0034 Shiga , Japan 24 Central Astronomical Observatory of the Russian Academy of Sciences , St. Petersburg , Pulkovo , Russia 25 Astronomical observatory of Odessa University , Marazlievskaya st. 1-B , Odessa , Ukraine 26 Department of Astrophysics, Astronomy and Mechanics, University of Athens , 15784 Zografos , Athens , Greece 27 Shanghai Astronomical Observatory, Chinese Academy of Sciences , 200030 Shanghai , PR China 28 14 Craigieburn Street , 7510 Darfield , New Zealand 29 Istituto Spezzino Ricerche Astronomiche , 19125 La Spezia , Italy 30 Astronomical Observatory University of Siena , 53100 Siena , Italy 31 Astrocampania , 80063 Piano di Sorrento , Italy 32 4368-1, Akashina-Nanaki, Azumino, 399-7104 Nagano , Japan 33 University of Namur , NAmur Center for CompleX SYStems (naXys), Rempart de la Vierge 8 , 5000 Namur , Belgium 34 Koninklijke Sterrenwacht van België, Ringlaan 3 , 1180 Brussels , Belgium 35 45/192 Vimiera Rd , Marsfield , NSW 2122 , Australia 36 Department of computer Science, Jinan University , 510632 Guangzhou , PR China 37 Institut de Ciéncies de l’Espai (IEEC-CSIC), Campus UAB, Facultat de Ciéncies , Torre C5 parell 2n pis, 08193 Bellaterra , Catalonia , Spain 38 Observatory and Planetarium Praha , Kralovska obora 233 170 21 Praha 7 , Czech Republic 39 26 impasse des Forsythias , 06560 Valbonne , France 40 Observatório do Valongo/UFRJ , Ladeira Pedro Antonio 43, RJ 23. 070-200 Rio de Janeiro , Brazil 41 Organizzazione Ricerche e Studi di Astronomia , Palermo , Italy 42 Kourovskaya observatory of the Ural Federal University , Prospect Lenina 51 , 620000 Ecaterinbourg , Russia 43 Gruppo Astrofili di Piacenza , Italy 44 Scaggsville , Maryland , USA 45 Fessenkov Astrophysical Institute , Alma-Ata , Kazakhstan 46 RASNZ Occultation Section, 3 Hughes Street , Waikanae Beach , New Zealand 47 Newark , New York , USA 48 Associazione Iblea Divulgazione Astronomica , 497100 Ragusa , Italy 49 9 Payling Lane, 8052 Christchurch , Christchurch , New Zealand 50 PO Box 117 , Chester , GA 31012 , USA 51 8 rue des Ormes , 67450 Mundolsheim , France 52 281, Kasadashinden, Inabe , Mie , 511-0205 , Japan 53 Virtual Telescope Project , Via Madonna de Loco 47 , 03023 Ceccano (FR) , Italy 54 Observatorio Nacional/MCTI , R. General Jose Cristino 77, RJ 20. 921-400 Rio de Janeiro , Brazil 55 Centro Universitário Estadual da Zona Oeste , Av. Manuel Caldeira de Alvarenga 1203, RJ 23. 070-200 Rio de Janeiro , Brazil 56 3 Lupin Pl , Murrumbateman , NSW 2582 , Australia 57 CNRS, LAB, UMR 5804 , 33270 Floirac , France ⋆ J. P. Rousselle died in 2009. e-mail: Jean-Eudes.Arlot@imcce.fr 09 12 2014 09 12 2014 12 2014 572 aa/2014/12 A120 20 3 2014 15 5 2014 © ESO, 2014 2014 ESO Context. In 2009, the Sun and the Earth passed through the equatorial plane of Jupiter and therefore the orbital planes of its main satellites. It was the equinox on Jupiter. This occurrence made mutual occultations and eclipses between the satellites possible. Experience has shown that the observations of such events provide accurate astrometric data able to bring new information on the dynamics of the Galilean satellites. Observations are made under the form of photometric measurements, but need to be made through the organization of a worldwide observation campaign maximizing the number and the quality of the data obtained. Aims. This work focuses on processing the complete database of photometric observations of the mutual occultations and eclipses of the Galilean satellites of Jupiter made during the international campaign in 2009. The final goal is to derive new accurate astrometric data. Methods. We used an accurate photometric model of mutual events adequate with the accuracy of the observation. Our original method was applied to derive astrometric data from photometric observations of mutual occultations and eclipses of the Galilean satellites of Jupiter. Results. We processed the 457 lightcurves obtained during the international campaign of photometric observations of the Galilean satellites of Jupiter in 2009. Compared with the theory, for successful observations, the r.m.s. of O–C residuals are equal to 45.8 mas and 81.1 mas in right ascension and declination, respectively; the mean O–C residuals are equal to –2 mas and –9 mas in right ascension and declination, respectively, for mutual occultations; and –6 mas and +1 mas in right ascension and declination, respectively, for mutual eclipses. astronomical databases: miscellaneous planets and satellites: general occultations eclipses ephemerides idline A&A 572, A120 (2014) cover_date December 2014 first_month 12 last_month 12 first_year 2014 last_year 2014 This work was supported by the Russian Foundation for Basic Research (project no. 12-02-00294), by The European contract ESPaCE (FP7-grant agreement 263466), by the Scientific Council of Paris Observatory, by the CNRS PICS 3840 France-Russia, by the Programme National de Planétologie (CNES and CNRS) and by the National Science Foundation of China (Grant No 11273014) and the Fundamental Research Funds for the Central Universities.

Context. The photometry of mutual occultations and eclipses of natural planetary satellites can be used to infer very accurate astrometric data. This can be achieved by processing the light curves of the satellites observed during international campaigns of photometric observations of these mutual events. Aims. This work focuses on processing the complete database of photometric observations of the mutual occultations and eclipses of the Uranian satellites made during the international campaign in 2007. The final goal is to derive new accurate astrometric data. Methods. We used an accurate photometric model of mutual events that explicitly depends on parameters that these accurate observations should be sensitive to, including the albedos of the satellites. Our original method is applied to derive astrometric data in relative positions from photometric observations of mutual occultations and eclipses of the Uranian satellites. Results. We process the 41 light-curves obtained during the international campaign of photometric observations of the Uranian satellites in 2007. The root-mean-square (rms) of the residuals “observations minus calculations” (O‐C) with respect to theory for the best 34 observations are equal to 10.3 and 17.7 mas in right ascension and declination, respectively. For five observations only the position angle was derived. Topocentric or heliocentric angular differences for satellites pairs were obtained from 25 central instant offsets between observation and theory during the time period from May 4, 2007 to January 4, 2008. Conclusions. The rms of the residuals is from 10 to 20 mas that corresponds in situ to 10 to 20 km. These mutual event observations appear to be the most accurate astrometric ground-based observations of the major Uranian satellites to-date and should be used for dynamical purposes.