Hunting for Hydrated Minerals on Trans-Neptunian Objects

We present new optical reflectance spectra of three potentially silicate-rich trans-Neptunian objects (TNOs). These spectra were obtained with the aim of confirming past hints and detections of λ ∼ 0.7 μ m absorption features associated with the presence of iron-bearing phyllosilicates. Our new spec...

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Main Authors: Tom Seccull, Wesley C. Fraser, Dominik A. Kiersz, Thomas H. Puzia
Format: Article
Language:English
Published: IOP Publishing 2024-01-01
Series:The Planetary Science Journal
Subjects:
Online Access:https://doi.org/10.3847/PSJ/ad16dd
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author Tom Seccull
Wesley C. Fraser
Dominik A. Kiersz
Thomas H. Puzia
author_facet Tom Seccull
Wesley C. Fraser
Dominik A. Kiersz
Thomas H. Puzia
author_sort Tom Seccull
collection DOAJ
description We present new optical reflectance spectra of three potentially silicate-rich trans-Neptunian objects (TNOs). These spectra were obtained with the aim of confirming past hints and detections of λ ∼ 0.7 μ m absorption features associated with the presence of iron-bearing phyllosilicates. Our new spectrum of 120216 (2004 EW _95 ) presents clearly detected absorption features that are similar in shape to hydrated mineral absorption bands present in the spectra of aqueously altered outer main belt asteroids. Four new reflectance spectra of 208996 (2003 AZ _84 ) obtained at separate epochs all appear featureless, but they vary significantly in spectral gradient (between ∼3.5%/0.1 μ m and ∼8.5%/0.1 μ m) on a timescale consistent with this object’s nominal rotational period. We report the first four optical reflectance spectra of 90568 (2004 GV _9 ), finding them all to be featureless but consistent with colors previously reported for this object. We speculate that impacts are the only mechanism capable of delivering, excavating, or forming hydrated minerals at the surfaces of TNOs in detectable concentrations; as a result, any deposits of hydrated minerals on TNOs are predicted to be localized and associated with impact sites. Globally altered TNOs (as observationally suggested for 2004 EW _95 ) plausibly formed more easily at smaller heliocentric distances ( r _H < 15 au) before being transplanted into the current trans-Neptunian population.
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spelling doaj.art-a4050ea1918c4d568f954ba96eebc1782024-02-20T13:01:58ZengIOP PublishingThe Planetary Science Journal2632-33382024-01-01524210.3847/PSJ/ad16ddHunting for Hydrated Minerals on Trans-Neptunian ObjectsTom Seccull0https://orcid.org/0000-0001-5605-1702Wesley C. Fraser1https://orcid.org/0000-0001-6680-6558Dominik A. Kiersz2https://orcid.org/0000-0001-5787-9034Thomas H. Puzia3https://orcid.org/0000-0003-0350-7061Gemini Observatory/NSF’s NOIRLab , 670 N. A’ohoku Place, Hilo, HI 96720, USA ; tom.seccull@proton.meHerzberg Institute of Astrophysics , 5071 West Saanich Road, Victoria, BC V9E 2E7, Canada; Department of Physics and Astronomy, University of Victoria , Victoria, BC V8P 5C2, CanadaIndependent Researcher , Belfast, UKInstitute of Astrophysics , Pontificia Universidad Católica de Chile, Av. Vicuña MacKenna 4860, 7820436, Santiago, ChileWe present new optical reflectance spectra of three potentially silicate-rich trans-Neptunian objects (TNOs). These spectra were obtained with the aim of confirming past hints and detections of λ ∼ 0.7 μ m absorption features associated with the presence of iron-bearing phyllosilicates. Our new spectrum of 120216 (2004 EW _95 ) presents clearly detected absorption features that are similar in shape to hydrated mineral absorption bands present in the spectra of aqueously altered outer main belt asteroids. Four new reflectance spectra of 208996 (2003 AZ _84 ) obtained at separate epochs all appear featureless, but they vary significantly in spectral gradient (between ∼3.5%/0.1 μ m and ∼8.5%/0.1 μ m) on a timescale consistent with this object’s nominal rotational period. We report the first four optical reflectance spectra of 90568 (2004 GV _9 ), finding them all to be featureless but consistent with colors previously reported for this object. We speculate that impacts are the only mechanism capable of delivering, excavating, or forming hydrated minerals at the surfaces of TNOs in detectable concentrations; as a result, any deposits of hydrated minerals on TNOs are predicted to be localized and associated with impact sites. Globally altered TNOs (as observationally suggested for 2004 EW _95 ) plausibly formed more easily at smaller heliocentric distances ( r _H < 15 au) before being transplanted into the current trans-Neptunian population.https://doi.org/10.3847/PSJ/ad16ddTrans-Neptunian objectsPlanetary thermal historiesAsteroidsSpectroscopy
spellingShingle Tom Seccull
Wesley C. Fraser
Dominik A. Kiersz
Thomas H. Puzia
Hunting for Hydrated Minerals on Trans-Neptunian Objects
The Planetary Science Journal
Trans-Neptunian objects
Planetary thermal histories
Asteroids
Spectroscopy
title Hunting for Hydrated Minerals on Trans-Neptunian Objects
title_full Hunting for Hydrated Minerals on Trans-Neptunian Objects
title_fullStr Hunting for Hydrated Minerals on Trans-Neptunian Objects
title_full_unstemmed Hunting for Hydrated Minerals on Trans-Neptunian Objects
title_short Hunting for Hydrated Minerals on Trans-Neptunian Objects
title_sort hunting for hydrated minerals on trans neptunian objects
topic Trans-Neptunian objects
Planetary thermal histories
Asteroids
Spectroscopy
url https://doi.org/10.3847/PSJ/ad16dd
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