Lower atmosphere and pressure evolution on Pluto from ground-based stellar occultations, 1988–2016

E. Meza (1) , B. Sicardy (1) , M. Assafin (2) , J. L. Ortiz , T. Bertrand (3) , E. Lellouch (1) , F. Forget (4) , D. Bérard (1) , A. Doressoundiram (1) , J. Lecacheux (1) , J. Marques Oliveira (1) , F. Roques (1) , T. Widemann (1) , F. Colas (5) , F. Vachier (5) , S. Renner (6, 5) , R. Leiva (7) , F. Braga-Ribas (1) , G. Benedetti-Rossi (8) , J. I. B. Camargo (8) , A. Dias-Oliveira (8) , B. Morgado (8) , A. R. Gomes-Júnior (9) , R. Vieira-Martins (10) , R. Behrend (11) , A. Castro Tirado , R. Duffard (12) , N. Morales (12) , P. Santos-Sanz , M. Jelínek (13) , R. Cunniffe , R. Querel (14) , M. Harnisch , R. Jansen , A. Pennell , S. Todd , V. D. Ivanov , C. Opitom (15) , M. Gillon , E. Jehin (16) , J. Manfroid (17) , J. Pollock (18) , D. E. Reichart , J. B. Haislip , K. M. Ivarsen , A. P. Lacluyze , A. Maury (19) , R. Gil-Hutton (20) , V. Dhillon (21) , S. Littlefair , T. Marsh , C. Veillet , K.-L. Bath , W. Beisker , H.-J. Bode , M. Kretlow , D. Herald , D. Gault (22) , S. Kerr (23) , H. Pavlov , O. Faragó , O. Klös , E. Frappa (24) , M. Lavayssière (25) , A. A. Cole (26) , A. B. Giles , J. G. Greenhill , K. M. Hill , M. W. Buie , C. B. Olkin , E. F. Young (27) , L. A. Young , L. H. Wasserman , M. Devogèle (28) , R. G. French , F. B. Bianco , F. Marchis (29, 1) , N. Brosch (30) , S. Kaspi , D. Polishook (31) , I. Manulis , M. Ait Moulay Larbi , Z. Benkhaldoun (32) , A. Daassou , Y. El Azhari , Y. Moulane (17) , J. Broughton , J. Milner , T. Dobosz , G. Bolt , B. Lade (33) , A. Gilmore , P. Kilmartin , W. H. Allen , P. B. Graham , B. Loader , G. Mckay , J. Talbot (34) , S. Parker , L. Abe (35) , Ph. Bendjoya (28) , J.-P. Rivet (28) , D. Vernet (36) , L. Di Fabrizio , V. Lorenzi , A. Magazzú , E. Molinari , K. Gazeas , L. Tzouganatos , A. Carbognani (37) , G. Bonnoli , A. Marchini (38) , G. Leto , R. Zanmar Sanchez , L. Mancini , B. Kattentidt , M. Dohrmann , K. Guhl , W. Rothe , K. Walzel , G. Wortmann , A. Eberle , D. Hampf , J. Ohlert , G. Krannich , G. Murawsky , B. Gährken , D. Gloistein , S. Alonso , A. Román , J.-E. Communal , F. Jabet , S. Devisscher , J. Sérot (39) , T. Janik (40) , Z. Moravec , P. Machado , A. Selva , C. Perelló , J. Rovira , M. Conti , R. Papini , F. Salvaggio , A. Noschese , V. Tsamis (41) , K. Tigani (41) , Pierre Barroy (42) , M. Irzyk , D. Neel , J. P. Godard (43) , D. Lanoiselée , P. Sogorb , D. Vérilhac , M. Bretton (44) , F. Signoret , F. Ciabattari , R. Naves (45) , M. Boutet , J. de Queiroz , P. Lindner (46) , K. Lindner , P. Enskonatus , G. Dangl , T. Tordai , H. Eichler , J. Hattenbach , C. Peterson , L. A. Molnar , R. R. Howell , J. Desmars (1)

1 LESIA (UMR_8109) - Laboratoire d'études spatiales et d'instrumentation en astrophysique
2 Observatório do Valongo/UFRJ [Rio de Janeiro]
3 CHU Nîmes - Centre Hospitalier Universitaire de Nîmes
4 LMD - Laboratoire de Météorologie Dynamique (UMR 8539)
5 IMCCE - Institut de Mécanique Céleste et de Calcul des Ephémérides
6 LMU - Ludwig-Maximilians University [Munich]
7 SwRI - Southwest Research Institute [Boulder]
8 Observatorio Nacional [Rio de Janeiro]
9 UNESP - Universidade Estadual Paulista Júlio de Mesquita Filho = São Paulo State University
10 Observatório Nacional/MCT
11 ObsGE - Observatoire Astronomique de l'Université de Genève
12 IAA - Instituto de Astrofísica de Andalucía
13 UZEI PRAGUE CZE
14 NIWA - National Institute of Water and Atmospheric Research [Lauder]
15 ESO - European Southern Observatory [Santiago]
16 Institut d'Astrophysique et de Géophysique [Liège]
17 STAR - Space Sciences, Technologies and Astrophysics Research Institute
18 Department of Physics and Astronomy [Boone]
19 DAP - Département d'Astrophysique (ex SAP)
20 UNSJ - Universidad Nacional de San Juan [Argentine]
21 University of Sheffield [Sheffield]
22 Kuriwa Observatory
23 AAQ - Astronomical Association of Queensland
24 Euraster
25 Observatoire de Dax
26 CSES - Cardiff School of European Studies
27 EPSS - Department of Earth, Planetary and Space Sciences [Los Angeles]
28 LAGRANGE - Joseph Louis LAGRANGE
29 Fundació Privada Observatori Esteve Duran
30 The Wise Observatory and The Raymond & Beverly Sackler School of Physics and Astronomy
31 Wise Observatory and Department of geophysics and planetary sciences
32 UCA - Université Cadi Ayyad [Marrakech]
33 Stockport Observatory
34 Occultation Section [Wellington]
35 FIZEAU - Laboratoire Hippolyte Fizeau
36 OCA - Observatoire de la Côte d'Azur
37 CASSIOPEE - Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides
38 UNIPG - Università degli Studi di Perugia = University of Perugia
39 IP - Institut Pascal
40 PAN - Polska Akademia Nauk = Polish Academy of Sciences = Académie polonaise des sciences
41 Astronomical Union of Sparta [Sparta]
42 LPMC - Laboratoire de Physique de la Matière Condensée - UR UPJV 2081
43 PEIRENE - PEIRENE
44 OBP - Obervatoire des Baronnies Provençales
45 Observatorio Montcabre
46 ILL - Institut Laue-Langevin

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.

Mots clés: methods: observational; methods: data analysis; planets and satellites: atmospheres; techniques: photometric; planets and satellites: physical evolution; planets and satellites: terrestrial planets

Domaines: Astrophysique [astro-ph]

E. Meza, B. Sicardy, M. Assafin, J. L. Ortiz, T. Bertrand, et al.. Lower atmosphere and pressure evolution on Pluto from ground-based stellar occultations, 1988–2016. Astronomy and Astrophysics - A&A, 2019, 625, pp.A42. ⟨10.1051/0004-6361/201834281⟩. ⟨hal-02918688⟩