Pluto's Atmosphere from Stellar Occultations in 2012 and 2013

Autores
Gil-hutton, Ricardo Alfredo
Año de publicación
2015
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
We analyze two multi-chord stellar occultations by Pluto that were observed on 2012 July 18th and 2013 May 4th, and respectively monitored from five and six sites. They provide a total of fifteen light curves, 12 of which were used for a simultaneous fit that uses a unique temperature profile, assuming a clear (no haze) and pure N2 atmosphere, but allowing for a possible pressure variation between the two dates. We find a solution that satisfactorily fits (i.e., within the noise level) all of the 12 light curves, providing atmospheric constraints between ~1190 km (pressure ~11 μbar) and ~1450 km (pressure ~0.1 μbar) from Pluto's center. Our main results are: (1) the best-fitting temperature profile shows a stratosphere with a strong positive gradient between 1190 km (at 36 K, 11 μbar) and r = 1215 km (6.0 μbar), where a temperature maximum of 110 K is reached; above it is a mesosphere with a negative thermal gradient of −0.2 K km−1 up to ~1390 km (0.25 μbar), where the mesosphere connects itself to a more isothermal upper branch around 81 K; (2) the pressure shows a small (6%) but significant increase (6σ level) between the two dates; (3) without a troposphere, Pluto's radius is found to be ${R}_{{\rm{P}}}=1190\;\pm $ 5 km. Allowing for a troposphere, RP is constrained to lie between 1168 and 1195 km; and (4) the currently measured CO abundance is too small to explain the mesospheric negative thermal gradient. Cooling by HCN is possible, but only if this species is largely saturated. Alternative explanations like zonal winds or vertical compositional variations of the atmosphere are unable to explain the observed mesospheric negative thermal gradient.
Fil: Gil-hutton, Ricardo Alfredo. Consejo Nacional de Investigaciones Cientí­ficas y Técnicas. Centro Cientí­fico Tecnológico San Juan. Complejo Astronómico "El Leoncito"; Argentina. Universidad Nacional de San Juan; Argentina
Materia
Methods: Data Analysis
Methods: Observational
Planets And Satellites: Atmospheres
Planets And Satellites: Physical Evolution
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/7917
Acceder
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network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Pluto's Atmosphere from Stellar Occultations in 2012 and 2013Gil-hutton, Ricardo AlfredoMethods: Data AnalysisMethods: ObservationalPlanets And Satellites: AtmospheresPlanets And Satellites: Physical Evolutionhttps://purl.org/becyt/ford/1.3https://purl.org/becyt/ford/1We analyze two multi-chord stellar occultations by Pluto that were observed on 2012 July 18th and 2013 May 4th, and respectively monitored from five and six sites. They provide a total of fifteen light curves, 12 of which were used for a simultaneous fit that uses a unique temperature profile, assuming a clear (no haze) and pure N2 atmosphere, but allowing for a possible pressure variation between the two dates. We find a solution that satisfactorily fits (i.e., within the noise level) all of the 12 light curves, providing atmospheric constraints between ~1190 km (pressure ~11 μbar) and ~1450 km (pressure ~0.1 μbar) from Pluto's center. Our main results are: (1) the best-fitting temperature profile shows a stratosphere with a strong positive gradient between 1190 km (at 36 K, 11 μbar) and r = 1215 km (6.0 μbar), where a temperature maximum of 110 K is reached; above it is a mesosphere with a negative thermal gradient of −0.2 K km−1 up to ~1390 km (0.25 μbar), where the mesosphere connects itself to a more isothermal upper branch around 81 K; (2) the pressure shows a small (6%) but significant increase (6σ level) between the two dates; (3) without a troposphere, Pluto's radius is found to be ${R}_{{\rm{P}}}=1190\;\pm $ 5 km. Allowing for a troposphere, RP is constrained to lie between 1168 and 1195 km; and (4) the currently measured CO abundance is too small to explain the mesospheric negative thermal gradient. Cooling by HCN is possible, but only if this species is largely saturated. Alternative explanations like zonal winds or vertical compositional variations of the atmosphere are unable to explain the observed mesospheric negative thermal gradient.Fil: Gil-hutton, Ricardo Alfredo. Consejo Nacional de Investigaciones Cientí­ficas y Técnicas. Centro Cientí­fico Tecnológico San Juan. Complejo Astronómico "El Leoncito"; Argentina. Universidad Nacional de San Juan; ArgentinaIop Publishing2015-09info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/7917Gil-hutton, Ricardo Alfredo; Pluto's Atmosphere from Stellar Occultations in 2012 and 2013; Iop Publishing; Astrophysical Journal; 811; 1; 9-2015; 1-200004-637Xenginfo:eu-repo/semantics/altIdentifier/url/http://iopscience.iop.org/article/10.1088/0004-637X/811/1/53/meta;jsessionid=82B22A24CD0FB4D0C154B5B74041F97C.c1.iopscience.cld.iop.org#info:eu-repo/semantics/altIdentifier/doi/10.1088/0004-637X/811/1/53info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-10-22T11:33:51Zoai:ri.conicet.gov.ar:11336/7917instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-10-22 11:33:51.285CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Pluto's Atmosphere from Stellar Occultations in 2012 and 2013
title Pluto's Atmosphere from Stellar Occultations in 2012 and 2013
spellingShingle Pluto's Atmosphere from Stellar Occultations in 2012 and 2013
Gil-hutton, Ricardo Alfredo
Methods: Data Analysis
Methods: Observational
Planets And Satellites: Atmospheres
Planets And Satellites: Physical Evolution
title_short Pluto's Atmosphere from Stellar Occultations in 2012 and 2013
title_full Pluto's Atmosphere from Stellar Occultations in 2012 and 2013
title_fullStr Pluto's Atmosphere from Stellar Occultations in 2012 and 2013
title_full_unstemmed Pluto's Atmosphere from Stellar Occultations in 2012 and 2013
title_sort Pluto's Atmosphere from Stellar Occultations in 2012 and 2013
dc.creator.none.fl_str_mv Gil-hutton, Ricardo Alfredo
author Gil-hutton, Ricardo Alfredo
author_facet Gil-hutton, Ricardo Alfredo
author_role author
dc.subject.none.fl_str_mv Methods: Data Analysis
Methods: Observational
Planets And Satellites: Atmospheres
Planets And Satellites: Physical Evolution
topic Methods: Data Analysis
Methods: Observational
Planets And Satellites: Atmospheres
Planets And Satellites: Physical Evolution
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv We analyze two multi-chord stellar occultations by Pluto that were observed on 2012 July 18th and 2013 May 4th, and respectively monitored from five and six sites. They provide a total of fifteen light curves, 12 of which were used for a simultaneous fit that uses a unique temperature profile, assuming a clear (no haze) and pure N2 atmosphere, but allowing for a possible pressure variation between the two dates. We find a solution that satisfactorily fits (i.e., within the noise level) all of the 12 light curves, providing atmospheric constraints between ~1190 km (pressure ~11 μbar) and ~1450 km (pressure ~0.1 μbar) from Pluto's center. Our main results are: (1) the best-fitting temperature profile shows a stratosphere with a strong positive gradient between 1190 km (at 36 K, 11 μbar) and r = 1215 km (6.0 μbar), where a temperature maximum of 110 K is reached; above it is a mesosphere with a negative thermal gradient of −0.2 K km−1 up to ~1390 km (0.25 μbar), where the mesosphere connects itself to a more isothermal upper branch around 81 K; (2) the pressure shows a small (6%) but significant increase (6σ level) between the two dates; (3) without a troposphere, Pluto's radius is found to be ${R}_{{\rm{P}}}=1190\;\pm $ 5 km. Allowing for a troposphere, RP is constrained to lie between 1168 and 1195 km; and (4) the currently measured CO abundance is too small to explain the mesospheric negative thermal gradient. Cooling by HCN is possible, but only if this species is largely saturated. Alternative explanations like zonal winds or vertical compositional variations of the atmosphere are unable to explain the observed mesospheric negative thermal gradient.
Fil: Gil-hutton, Ricardo Alfredo. Consejo Nacional de Investigaciones Cientí­ficas y Técnicas. Centro Cientí­fico Tecnológico San Juan. Complejo Astronómico "El Leoncito"; Argentina. Universidad Nacional de San Juan; Argentina
description We analyze two multi-chord stellar occultations by Pluto that were observed on 2012 July 18th and 2013 May 4th, and respectively monitored from five and six sites. They provide a total of fifteen light curves, 12 of which were used for a simultaneous fit that uses a unique temperature profile, assuming a clear (no haze) and pure N2 atmosphere, but allowing for a possible pressure variation between the two dates. We find a solution that satisfactorily fits (i.e., within the noise level) all of the 12 light curves, providing atmospheric constraints between ~1190 km (pressure ~11 μbar) and ~1450 km (pressure ~0.1 μbar) from Pluto's center. Our main results are: (1) the best-fitting temperature profile shows a stratosphere with a strong positive gradient between 1190 km (at 36 K, 11 μbar) and r = 1215 km (6.0 μbar), where a temperature maximum of 110 K is reached; above it is a mesosphere with a negative thermal gradient of −0.2 K km−1 up to ~1390 km (0.25 μbar), where the mesosphere connects itself to a more isothermal upper branch around 81 K; (2) the pressure shows a small (6%) but significant increase (6σ level) between the two dates; (3) without a troposphere, Pluto's radius is found to be ${R}_{{\rm{P}}}=1190\;\pm $ 5 km. Allowing for a troposphere, RP is constrained to lie between 1168 and 1195 km; and (4) the currently measured CO abundance is too small to explain the mesospheric negative thermal gradient. Cooling by HCN is possible, but only if this species is largely saturated. Alternative explanations like zonal winds or vertical compositional variations of the atmosphere are unable to explain the observed mesospheric negative thermal gradient.
publishDate 2015
dc.date.none.fl_str_mv 2015-09
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/7917
Gil-hutton, Ricardo Alfredo; Pluto's Atmosphere from Stellar Occultations in 2012 and 2013; Iop Publishing; Astrophysical Journal; 811; 1; 9-2015; 1-20
0004-637X
url http://hdl.handle.net/11336/7917
identifier_str_mv Gil-hutton, Ricardo Alfredo; Pluto's Atmosphere from Stellar Occultations in 2012 and 2013; Iop Publishing; Astrophysical Journal; 811; 1; 9-2015; 1-20
0004-637X
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/http://iopscience.iop.org/article/10.1088/0004-637X/811/1/53/meta;jsessionid=82B22A24CD0FB4D0C154B5B74041F97C.c1.iopscience.cld.iop.org#
info:eu-repo/semantics/altIdentifier/doi/10.1088/0004-637X/811/1/53
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
dc.publisher.none.fl_str_mv Iop Publishing
publisher.none.fl_str_mv Iop Publishing
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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score 12.982451

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