Methane absorption variations in the spectrum of Pluto

Marc W. Buie, Uwe - Fink

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

Absolute spectrophotometry of Pluto in the wavelength range of 5600 to 10,500 Å was obtained on 4 nights covering lightcurve phases of 0.18, 0.35, 0.49, and 0.98. The four phases included minimum light (0.98) and one near maximum light (0.49). The spectra reveal significant variations in the absorption depths of the methane bands at 6200, 7200, 7900, 8400, 8600, 8900, and 10,000 Å. The minimum amount of absorption was found to occur at minimum light. This variation would imply a 30° change in the column abundance of methane within 3 days. A model employing an anisotropic surface distribution of methane frost and a clear layer of CH4 gas was developed to explain the variation in absorption strength with rotational phase. The fit to the overall spectrum requires the presence of a frost with particle sizes on the order of a few millimeters. An upper limit of 5.5 m-am is derived for the one-way column abundance of CH4 gas. An equally good fit to the variation of the 7200-Å band is obtained if the atmosphere is removed from the model entirely.

Original languageEnglish (US)
Pages (from-to)483-498
Number of pages16
JournalIcarus
Volume70
Issue number3
DOIs
StatePublished - 1987

Fingerprint

Pluto (planet)
Pluto
methane
frost
spectrophotometry
gas
gases
particle size
night
wavelength
coverings
atmosphere
atmospheres
wavelengths

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Methane absorption variations in the spectrum of Pluto. / Buie, Marc W.; Fink, Uwe -.

In: Icarus, Vol. 70, No. 3, 1987, p. 483-498.

Research output: Contribution to journalArticle

Buie, Marc W. ; Fink, Uwe -. / Methane absorption variations in the spectrum of Pluto. In: Icarus. 1987 ; Vol. 70, No. 3. pp. 483-498.
@article{73adc9d229814df0aad64b0e3e99b362,
title = "Methane absorption variations in the spectrum of Pluto",
abstract = "Absolute spectrophotometry of Pluto in the wavelength range of 5600 to 10,500 {\AA} was obtained on 4 nights covering lightcurve phases of 0.18, 0.35, 0.49, and 0.98. The four phases included minimum light (0.98) and one near maximum light (0.49). The spectra reveal significant variations in the absorption depths of the methane bands at 6200, 7200, 7900, 8400, 8600, 8900, and 10,000 {\AA}. The minimum amount of absorption was found to occur at minimum light. This variation would imply a 30° change in the column abundance of methane within 3 days. A model employing an anisotropic surface distribution of methane frost and a clear layer of CH4 gas was developed to explain the variation in absorption strength with rotational phase. The fit to the overall spectrum requires the presence of a frost with particle sizes on the order of a few millimeters. An upper limit of 5.5 m-am is derived for the one-way column abundance of CH4 gas. An equally good fit to the variation of the 7200-{\AA} band is obtained if the atmosphere is removed from the model entirely.",
author = "Buie, {Marc W.} and Fink, {Uwe -}",
year = "1987",
doi = "10.1016/0019-1035(87)90090-X",
language = "English (US)",
volume = "70",
pages = "483--498",
journal = "Icarus",
issn = "0019-1035",
publisher = "Academic Press Inc.",
number = "3",

}

TY - JOUR

T1 - Methane absorption variations in the spectrum of Pluto

AU - Buie, Marc W.

AU - Fink, Uwe -

PY - 1987

Y1 - 1987

N2 - Absolute spectrophotometry of Pluto in the wavelength range of 5600 to 10,500 Å was obtained on 4 nights covering lightcurve phases of 0.18, 0.35, 0.49, and 0.98. The four phases included minimum light (0.98) and one near maximum light (0.49). The spectra reveal significant variations in the absorption depths of the methane bands at 6200, 7200, 7900, 8400, 8600, 8900, and 10,000 Å. The minimum amount of absorption was found to occur at minimum light. This variation would imply a 30° change in the column abundance of methane within 3 days. A model employing an anisotropic surface distribution of methane frost and a clear layer of CH4 gas was developed to explain the variation in absorption strength with rotational phase. The fit to the overall spectrum requires the presence of a frost with particle sizes on the order of a few millimeters. An upper limit of 5.5 m-am is derived for the one-way column abundance of CH4 gas. An equally good fit to the variation of the 7200-Å band is obtained if the atmosphere is removed from the model entirely.

AB - Absolute spectrophotometry of Pluto in the wavelength range of 5600 to 10,500 Å was obtained on 4 nights covering lightcurve phases of 0.18, 0.35, 0.49, and 0.98. The four phases included minimum light (0.98) and one near maximum light (0.49). The spectra reveal significant variations in the absorption depths of the methane bands at 6200, 7200, 7900, 8400, 8600, 8900, and 10,000 Å. The minimum amount of absorption was found to occur at minimum light. This variation would imply a 30° change in the column abundance of methane within 3 days. A model employing an anisotropic surface distribution of methane frost and a clear layer of CH4 gas was developed to explain the variation in absorption strength with rotational phase. The fit to the overall spectrum requires the presence of a frost with particle sizes on the order of a few millimeters. An upper limit of 5.5 m-am is derived for the one-way column abundance of CH4 gas. An equally good fit to the variation of the 7200-Å band is obtained if the atmosphere is removed from the model entirely.

UR - http://www.scopus.com/inward/record.url?scp=0001117475&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0001117475&partnerID=8YFLogxK

U2 - 10.1016/0019-1035(87)90090-X

DO - 10.1016/0019-1035(87)90090-X

M3 - Article

AN - SCOPUS:0001117475

VL - 70

SP - 483

EP - 498

JO - Icarus

JF - Icarus

SN - 0019-1035

IS - 3

ER -