J/A+A/659/A136 Triton light curves from 05/10/2017 (Marques Oliveira+, 2022)
Constraints on the structure and seasonal variations of Triton's atmosphere from
the 5 October 2017 stellar occultation and previous observations.
Marques Oliveira J., Sicardy B., Gomes-Junior A.R., Ortiz J.L.,
Strobel D.F., Bertrand T., Forget F., Lellouch E., Desmars J., Berard D.,
Doressoundiram A., Lecacheux J., Leiva R., Meza E., Roques F., Souami D.,
Widemann T., Santos-Sanz P., Morales N., Duffard R.,
Fernandez-Valenzuela E., Castro-Tirado A.J., Braga-Ribas F., Morgado B.E.,
Assafin M., Camargo J.I.B., Vieira-Martins R., Benedetti-Rossi G.,
Santos-Filho S., Banda-Huarca M.V., Quispe-Huaynasi F., Pereira C.L.,
Rommel F.L., Margoti G., Dias-Oliveira A., Colas F., Berthier J.,
Renner S., Hueso R., Perez-Hoyos S., Sanchez-Lavega A., Rojas J.F.,
Beisker W., Kretlow M., Herald D., Gault D., Bath K.-L., Bode H.-J.,
Bredner E., Guhl K., Haymes T.V., Hummel E., Kattentidt B., Klos O.,
Pratt A., Thome B., Avdellidou C., Gazeas K., Karampotsiou E.,
Tzouganatos L., Kardasis E., Christou A.A., Xilouris E.M., Alikakos I.,
Gourzelas A., Liakos A., Charmandaris V., Jelinek M., Strobl J.,
Eberle A., Rapp K., Gahrken B., Klemt B., Kowollik S., Bitzer R.,
Miller M., Herzogenrath G., Frangenberg D., Brandis L., Puetz I.,
Perdelwitz V., Piehler G.M., Riepe P., von Poschinger K., Baruffetti P.,
Cenadelli D., Christille J.-M., Ciabattari F., Di Luca R., Alboresi D.,
Leto G., Zanmar Sanchez R., Bruno P., Occhipinti G., Morrone L.,
Cupolino L., Noschese A., Vecchione A., Scalia C., Lo Savio R.,
Giardina G., Kamoun S., Barbosa R., Behrend R., Spano M., Bouchet E.,
Cottier M., Falco L., Gallego S., Tortorelli L., Sposetti S.,
Sussenbach J., Van Den Abbeel F., Andre P., Llibre M., Pailler F.,
Ardissone J., Boutet M., Sanchez J., Bretton M., Cailleau A., Pic V.,
Granier L., Chauvet R., Conjat M., Dauvergne J.L., Dechambre O., Delay P.,
Delcroix M., Rousselot L., Ferreira J., Machado P., Tanga P., Rivet J.-P.,
Frappa E., Irzyk M., Jabet F., Kaschinski M., Klotz A., Rieugnie Y.,
Klotz A.N., Labrevoir O., Lavandier D., Walliang D., Leroy A., Bouley S.,
Lisciandra S., Coliac J.-F., Metz F., Erpelding D., Nougayrede P.,
Midavaine T., Miniou M., Moindrot S., Morel P., Reginato B., Reginato E.,
Rudelle J., Tregon B., Tanguy R., David J., Thuillot W., Hestroffer D.,
Vaudescal G., Baba Aissa D., Grigahcene Z., Briggs D., Broadbent S.,
Denyer P., Haigh N.J., Quinn N., Thurston G., Fossey S.J., Arena C.,
Jennings M., Talbot J., Alonso S., Roman Reche A., Casanova V., Briggs E.,
Iglesias-Marzoa R., Abril Ibanez J., Diaz Martin M.C., Gonzalez H.,
Maestre Garcia J.L., Marchant J., Ordonez-Etxeberria I., Martorell P.,
Salamero J., Organero F., Ana L., Fonseca F., Peris V., Brevia O.,
Selva A., Perello C., Cabedo V., Goncalves R., Ferreira M.,
Marques Dias F., Daassou A., Barkaoui K., Benkhaldoun Z., Guennoun M.,
Chouqar J., Jehin E., Rinner C., Lloyd J., El Moutamid M., Lamarche C.,
Pollock J.T., Caton D.B., Kouprianov V., Timerson B.W., Blanchard G.,
Payet B., Peyrot A., Teng-Chuen-Yu J.-P., Francoise J., Mondon B.,
Payet T., Boissel C., Castets M., Hubbard W.B., Hill R., Reitsema H.J.,
Mousis O., Ball L., Neilsen G., Hutcheon S., Lay K., Anderson P., Moy M.,
Jonsen M., Pink I., Walters R., Downs B.
<Astron. Astrophys. 659, A136 (2022)>
=2022A&A...659A.136M 2022A&A...659A.136M (SIMBAD/NED BibCode)
ADC_Keywords: Solar system ; Planets ; Photometry
Keywords: methods: data analysis - methods: observational -
planets and satellites: atmospheres -
planets and satellites: physical evolution - techniques: photometric
Abstract:
A stellar occultation by Neptune's main satellite, Triton, was
observed on 5 October 2017 from Europe, North Africa, and the USA. We
derived 90 light curves from this event, 42 of which yielded a central
flash detection.
We aimed at constraining Triton's atmospheric structure and the
seasonal variations of its atmospheric pressure since the Voyager 2
epoch (1989). We also derived the shape of the lower atmosphere from
central flash analysis.
We used Abel inversions and direct ray-tracing code to provide the
density, pressure, and temperature profiles in the altitude range ∼8km
to ∼190km, corresponding to pressure levels from 9ubar down to a few
nanobars.
(i) A pressure of 1.18±0.03ubar is found at a reference radius of
1400km (47km altitude). (ii) A new analysis of the Voyager 2 radio
science occultation shows that this is consistent with an
extrapolation of pressure down to the surface pressure obtained in
1989. (iii) A survey of occultations obtained between 1989 and 2017
suggests that an enhancement in surface pressure as reported during
the 1990s might be real, but debatable, due to very few high S/N light
curves and data accessible for reanalysis. The volatile transport
model analysed supports a moderate increase in surface pressure, with
a maximum value around 2005-2015 no higher than 23ubar. The pressures
observed in 1995-1997 and 2017 appear mutually inconsistent with the
volatile transport model presented here. (iv) The central flash
structure does not show evidence of an atmospheric distortion. We find
an upper limit of 0.0011 for the apparent oblateness of the atmosphere
near the 8km altitude.
Description:
The data provided features all light curves from the 5 October 2017
event.
The names of the files are the same names, in lower caps and with no
spaces, that are presented in Figures C.1 and C.2.
The first column of all files is the time in seconds, starting on 5
October 2017 00:00:00 UTC.
The second column of all files is the normalised flux, where the
unocculted flux oscillates around 1.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
list.dat 59 90 List of light curves
lc/* . 90 Individual light curves
--------------------------------------------------------------------------------
See also:
J/A+AS/120/107 : 1989-1994 CCD observations of Triton (Veiga+ 1996)
J/A+AS/131/291 : 1995-1997 CCD positions of Triton (Veiga+ 1998)
J/MNRAS/376/1707 : 1996-2006 observations of Triton (Qiao+, 2007)
J/A+A/425/1107 : Observations of Triton and Proteus (Vieira Martins+, 2004)
J/A+A/617/L5 : Water delivery in Pluto & Triton atmospheres (Poppe+, 2018)
J/AJ/161/237 : Positions of Triton with Sheshan Station tel. (Zhang+, 2021)
Byte-by-byte Description of file:list.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 26 A26 --- FileName Name of the light curve file in subdirectory lc
28- 59 A32 --- Com Comments
--------------------------------------------------------------------------------
Byte-by-byte Description of file: lc/*
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 F18.12 s Time Time, starting on 5 October 2017
20- 34 E15.9 --- NFlux Normalised flux, where the unocculted flux
oscillates around 1
--------------------------------------------------------------------------------
Acknowledgements:
Joana Marques Oliveira, Joana.Oliveira(at)obspm.fr
(End) Patricia Vannier [CDS] 11-Feb-2022