Spectral determination of the colour and vertical structure of dark spots in Neptune’s atmosphere

Patrick Irwin; Jack Dobinson; Arjuna James; Michael H. Wong; Leigh Fletcher; Nicholas A  Teanby

doi:10.1038/s41550-023-02047-0

Spectral determination of the colour and vertical structure of dark spots in Neptune’s atmosphere

Patrick Irwin^*
, Jack Dobinson
, Arjuna James
, Michael H. Wong
, Leigh Fletcher
, Nicholas A Teanby

^*Corresponding author for this work

Research output: Contribution to journal › Article (Academic Journal) › peer-review

10 Citations (Scopus)

72 Downloads (Pure)

Abstract

Previous observations of dark vortices in Neptune’s atmosphere, such as Voyager2’s Great Dark Spot, have been made in only a few, broad-wavelength channels, which has hampered e↵orts to pinpoint their pressure level and what makes them dark. Here, we present Very Large Telescope (Chile) MUSE spectrometer observations of Hubble Space Telescope’s NDS-2018 dark spot, made in 2019. These medium-resolution 475 – 933 nm reflection spectra allow us to show that dark spots are caused by a darkening at short wavelengths (< 700 nm) of a deep ⇠5-bar aerosol layer, which we suggest is the H2S condensation layer. A deep bright spot, named DBS-2019, is also visible on the edge of NDS-2018, whose spectral signature is consistent with a brightening of the same 5-bar layer at longer wavelengths (> 700 nm). This bright feature is much deeper than previously studied dark spot companion clouds and may be connected with the circulation that generates and sustains such spots.

Original language	English
Pages (from-to)	1198-1207
Number of pages	10
Journal	Nature Astronomy
Volume	7
Issue number	10
Early online date	24 Aug 2023
DOIs	https://doi.org/10.1038/s41550-023-02047-0
Publication status	E-pub ahead of print - 24 Aug 2023

Bibliographical note

Funding Information:
The VLT’s MUSE observations were performed at the European Southern Observatory (ESO), under proposal 0104.C-0187. We are grateful to the United Kingdom Science and Technology Facilities Council for funding this research (P.G.J.I.: ST/S000461/1) and also the United Kingdom Space Agency (N.A.T.: ST/R001367/1). S.P.-H. and A.S.-L. have been supported by the Spanish project PID2019-109467GB-I00 (MINECO/FEDER, UE), Elkartek21/87 KK- 2021/00061 and Grupos Gobierno Vasco IT-1742-22. Some of this research (G.S.O.) was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). L.N.F. and M.T.R. were supported by a European Research Council Consolidator Grant (under the European Union’s Horizon 2020 research and innovation programme, grant agreement No. 723890) at the University of Leicester. I.d.P. and S.L.C. were supported in part by NSF grant AST-1615004 to UC Berkeley. Tracking of the longitude of NDS-2018 and the time variation of DBS-2019 utilized observations made with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. These observations are associated with programmes GO/DD-15502 and GO/DD-16057, which provided support for A.S., M.H.W., G.S.O. and L.S. For the purpose of Open Access, the corresponding author has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission.

Funding Information:
The VLT’s MUSE observations were performed at the European Southern Observatory (ESO), under proposal 0104.C-0187. We are grateful to the United Kingdom Science and Technology Facilities Council for funding this research (P.G.J.I.: ST/S000461/1) and also the United Kingdom Space Agency (N.A.T.: ST/R001367/1). S.P.-H. and A.S.-L. have been supported by the Spanish project PID2019-109467GB-I00 (MINECO/FEDER, UE), Elkartek21/87 KK- 2021/00061 and Grupos Gobierno Vasco IT-1742-22. Some of this research (G.S.O.) was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). L.N.F. and M.T.R. were supported by a European Research Council Consolidator Grant (under the European Union’s Horizon 2020 research and innovation programme, grant agreement No. 723890) at the University of Leicester. I.d.P. and S.L.C. were supported in part by NSF grant AST-1615004 to UC Berkeley. Tracking of the longitude of NDS-2018 and the time variation of DBS-2019 utilized observations made with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. These observations are associated with programmes GO/DD-15502 and GO/DD-16057, which provided support for A.S., M.H.W., G.S.O. and L.S. For the purpose of Open Access, the corresponding author has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission.

Publisher Copyright:
© 2023, The Author(s), under exclusive licence to Springer Nature Limited.

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10.1038/s41550-023-02047-0

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https://arxiv.org/abs/2308.12889Licence: CC BY

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Planetary Science at Bristol
Elliott, T. (Principal Investigator)
1/04/18 → 28/02/22
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Cite this

@article{340a29841247439b9f58cbaf2e716d5a,

title = "Spectral determination of the colour and vertical structure of dark spots in Neptune{\textquoteright}s atmosphere",

abstract = "Previous observations of dark vortices in Neptune{\textquoteright}s atmosphere, such as Voyager2{\textquoteright}s Great Dark Spot, have been made in only a few, broad-wavelength channels, which has hampered e↵orts to pinpoint their pressure level and what makes them dark. Here, we present Very Large Telescope (Chile) MUSE spectrometer observations of Hubble Space Telescope{\textquoteright}s NDS-2018 dark spot, made in 2019. These medium-resolution 475 – 933 nm reflection spectra allow us to show that dark spots are caused by a darkening at short wavelengths (< 700 nm) of a deep ⇠5-bar aerosol layer, which we suggest is the H2S condensation layer. A deep bright spot, named DBS-2019, is also visible on the edge of NDS-2018, whose spectral signature is consistent with a brightening of the same 5-bar layer at longer wavelengths (> 700 nm). This bright feature is much deeper than previously studied dark spot companion clouds and may be connected with the circulation that generates and sustains such spots. ",

author = "Patrick Irwin and Jack Dobinson and Arjuna James and Wong, \{Michael H.\} and Leigh Fletcher and Teanby, \{Nicholas A\}",

note = "Funding Information: The VLT{\textquoteright}s MUSE observations were performed at the European Southern Observatory (ESO), under proposal 0104.C-0187. We are grateful to the United Kingdom Science and Technology Facilities Council for funding this research (P.G.J.I.: ST/S000461/1) and also the United Kingdom Space Agency (N.A.T.: ST/R001367/1). S.P.-H. and A.S.-L. have been supported by the Spanish project PID2019-109467GB-I00 (MINECO/FEDER, UE), Elkartek21/87 KK- 2021/00061 and Grupos Gobierno Vasco IT-1742-22. Some of this research (G.S.O.) was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). L.N.F. and M.T.R. were supported by a European Research Council Consolidator Grant (under the European Union{\textquoteright}s Horizon 2020 research and innovation programme, grant agreement No. 723890) at the University of Leicester. I.d.P. and S.L.C. were supported in part by NSF grant AST-1615004 to UC Berkeley. Tracking of the longitude of NDS-2018 and the time variation of DBS-2019 utilized observations made with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. These observations are associated with programmes GO/DD-15502 and GO/DD-16057, which provided support for A.S., M.H.W., G.S.O. and L.S. For the purpose of Open Access, the corresponding author has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission. Funding Information: The VLT{\textquoteright}s MUSE observations were performed at the European Southern Observatory (ESO), under proposal 0104.C-0187. We are grateful to the United Kingdom Science and Technology Facilities Council for funding this research (P.G.J.I.: ST/S000461/1) and also the United Kingdom Space Agency (N.A.T.: ST/R001367/1). S.P.-H. and A.S.-L. have been supported by the Spanish project PID2019-109467GB-I00 (MINECO/FEDER, UE), Elkartek21/87 KK- 2021/00061 and Grupos Gobierno Vasco IT-1742-22. Some of this research (G.S.O.) was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). L.N.F. and M.T.R. were supported by a European Research Council Consolidator Grant (under the European Union{\textquoteright}s Horizon 2020 research and innovation programme, grant agreement No. 723890) at the University of Leicester. I.d.P. and S.L.C. were supported in part by NSF grant AST-1615004 to UC Berkeley. Tracking of the longitude of NDS-2018 and the time variation of DBS-2019 utilized observations made with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. These observations are associated with programmes GO/DD-15502 and GO/DD-16057, which provided support for A.S., M.H.W., G.S.O. and L.S. For the purpose of Open Access, the corresponding author has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission. Publisher Copyright: {\textcopyright} 2023, The Author(s), under exclusive licence to Springer Nature Limited.",

year = "2023",

month = aug,

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doi = "10.1038/s41550-023-02047-0",

language = "English",

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journal = "Nature Astronomy",

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T1 - Spectral determination of the colour and vertical structure of dark spots in Neptune’s atmosphere

AU - Irwin, Patrick

AU - Dobinson, Jack

AU - James, Arjuna

AU - Wong, Michael H.

AU - Fletcher, Leigh

AU - Teanby, Nicholas A

N1 - Funding Information: The VLT’s MUSE observations were performed at the European Southern Observatory (ESO), under proposal 0104.C-0187. We are grateful to the United Kingdom Science and Technology Facilities Council for funding this research (P.G.J.I.: ST/S000461/1) and also the United Kingdom Space Agency (N.A.T.: ST/R001367/1). S.P.-H. and A.S.-L. have been supported by the Spanish project PID2019-109467GB-I00 (MINECO/FEDER, UE), Elkartek21/87 KK- 2021/00061 and Grupos Gobierno Vasco IT-1742-22. Some of this research (G.S.O.) was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). L.N.F. and M.T.R. were supported by a European Research Council Consolidator Grant (under the European Union’s Horizon 2020 research and innovation programme, grant agreement No. 723890) at the University of Leicester. I.d.P. and S.L.C. were supported in part by NSF grant AST-1615004 to UC Berkeley. Tracking of the longitude of NDS-2018 and the time variation of DBS-2019 utilized observations made with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. These observations are associated with programmes GO/DD-15502 and GO/DD-16057, which provided support for A.S., M.H.W., G.S.O. and L.S. For the purpose of Open Access, the corresponding author has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission. Funding Information: The VLT’s MUSE observations were performed at the European Southern Observatory (ESO), under proposal 0104.C-0187. We are grateful to the United Kingdom Science and Technology Facilities Council for funding this research (P.G.J.I.: ST/S000461/1) and also the United Kingdom Space Agency (N.A.T.: ST/R001367/1). S.P.-H. and A.S.-L. have been supported by the Spanish project PID2019-109467GB-I00 (MINECO/FEDER, UE), Elkartek21/87 KK- 2021/00061 and Grupos Gobierno Vasco IT-1742-22. Some of this research (G.S.O.) was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). L.N.F. and M.T.R. were supported by a European Research Council Consolidator Grant (under the European Union’s Horizon 2020 research and innovation programme, grant agreement No. 723890) at the University of Leicester. I.d.P. and S.L.C. were supported in part by NSF grant AST-1615004 to UC Berkeley. Tracking of the longitude of NDS-2018 and the time variation of DBS-2019 utilized observations made with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. These observations are associated with programmes GO/DD-15502 and GO/DD-16057, which provided support for A.S., M.H.W., G.S.O. and L.S. For the purpose of Open Access, the corresponding author has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission. Publisher Copyright: © 2023, The Author(s), under exclusive licence to Springer Nature Limited.

PY - 2023/8/24

Y1 - 2023/8/24

N2 - Previous observations of dark vortices in Neptune’s atmosphere, such as Voyager2’s Great Dark Spot, have been made in only a few, broad-wavelength channels, which has hampered e↵orts to pinpoint their pressure level and what makes them dark. Here, we present Very Large Telescope (Chile) MUSE spectrometer observations of Hubble Space Telescope’s NDS-2018 dark spot, made in 2019. These medium-resolution 475 – 933 nm reflection spectra allow us to show that dark spots are caused by a darkening at short wavelengths (< 700 nm) of a deep ⇠5-bar aerosol layer, which we suggest is the H2S condensation layer. A deep bright spot, named DBS-2019, is also visible on the edge of NDS-2018, whose spectral signature is consistent with a brightening of the same 5-bar layer at longer wavelengths (> 700 nm). This bright feature is much deeper than previously studied dark spot companion clouds and may be connected with the circulation that generates and sustains such spots.

AB - Previous observations of dark vortices in Neptune’s atmosphere, such as Voyager2’s Great Dark Spot, have been made in only a few, broad-wavelength channels, which has hampered e↵orts to pinpoint their pressure level and what makes them dark. Here, we present Very Large Telescope (Chile) MUSE spectrometer observations of Hubble Space Telescope’s NDS-2018 dark spot, made in 2019. These medium-resolution 475 – 933 nm reflection spectra allow us to show that dark spots are caused by a darkening at short wavelengths (< 700 nm) of a deep ⇠5-bar aerosol layer, which we suggest is the H2S condensation layer. A deep bright spot, named DBS-2019, is also visible on the edge of NDS-2018, whose spectral signature is consistent with a brightening of the same 5-bar layer at longer wavelengths (> 700 nm). This bright feature is much deeper than previously studied dark spot companion clouds and may be connected with the circulation that generates and sustains such spots.

U2 - 10.1038/s41550-023-02047-0

DO - 10.1038/s41550-023-02047-0

M3 - Article (Academic Journal)

SN - 2397-3366

VL - 7

SP - 1198

EP - 1207

JO - Nature Astronomy

JF - Nature Astronomy

IS - 10

ER -

Spectral determination of the colour and vertical structure of dark spots in Neptune’s atmosphere

Abstract

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