Scholarlink

<p>The elemental compositions of exoplanets encode information about their formation environments and internal structures. While volatile ratios such as carbon-to-oxygen (C/O) are used to trace formation location, the rock-forming elements–magnesium (Mg), silicon (Si), and iron (Fe)–govern interior mineralogy and are commonly assumed to reflect the host star’s abundances. Yet this assumption remains largely untested. Ultra-hot Jupiters, gas-giant exoplanets with dayside temperatures above 3000 K, provide rare access to refractory elements that remain gaseous. Here we present high-resolution thermal emission spectroscopy of the exoplanet WASP-189b (<InlineEquation ID="IEq1"> <EquationSource Format="TEX">\({T}_{eq}=335{4}_{-34}^{+27}\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mrow> <mi>T</mi> </mrow> <mrow> <mi>e</mi> <mi>q</mi> </mrow> </msub> <mo>=</mo> <mn>335</mn> <msubsup> <mrow> <mn>4</mn> </mrow> <mrow> <mo>−</mo> <mn>34</mn> </mrow> <mrow> <mo>+</mo> <mn>27</mn> </mrow> </msubsup> </math></EquationSource> </InlineEquation> K) obtained with the Immersion Grating Infrared Spectrometer (IGRINS) on Gemini South. We detect neutral iron (Fe <span>i</span>), magnesium (Mg <span>i</span>), silicon (Si <span>i</span>), water (H<sub>2</sub>O), carbon monoxide (CO), and hydroxyl (OH) at signal-to-noise ratios exceeding 4, and retrieve their elemental abundances. We show that the Mg/Si, Fe/Mg, and Si/Fe ratios are consistent with stellar values, while the refractory-to-volatile ratio is enhanced by roughly a factor of 2. These findings demonstrate that giant-planet atmospheres can preserve stellar-like rock-forming ratios, providing an empirical validation of the stellar-proxy assumption that underpins planetary composition and formation models across exoplanet systems.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

A Stellar magnesium to silicon ratio in the atmosphere of an exoplanet

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年2月18日

查看全文
  • Jorge A. Sanchez,
  • Peter C. B. Smith,
  • Krishna Kanumalla,
  • Luis Welbanks,
  • Michael R. Line,
  • Stefan Pelletier,
  • Steven Desch,
  • Patrick Young,
  • Jennifer Patience,
  • Jacob Bean,
  • Matteo Brogi,
  • Dan Jaffe,
  • Gregory N. Mace,
  • Megan Weiner Mansfield,
  • Vatsal Panwar,
  • Vivien Parmentier,
  • Lorenzo Pino,
  • Arjun Baliga Savel,
  • Lennart van Sluijs,
  • Joost P. Wardenier

摘要

The elemental compositions of exoplanets encode information about their formation environments and internal structures. While volatile ratios such as carbon-to-oxygen (C/O) are used to trace formation location, the rock-forming elements–magnesium (Mg), silicon (Si), and iron (Fe)–govern interior mineralogy and are commonly assumed to reflect the host star’s abundances. Yet this assumption remains largely untested. Ultra-hot Jupiters, gas-giant exoplanets with dayside temperatures above 3000 K, provide rare access to refractory elements that remain gaseous. Here we present high-resolution thermal emission spectroscopy of the exoplanet WASP-189b ( \({T}_{eq}=335{4}_{-34}^{+27}\) T e q = 335 4 − 34 + 27 K) obtained with the Immersion Grating Infrared Spectrometer (IGRINS) on Gemini South. We detect neutral iron (Fe i), magnesium (Mg i), silicon (Si i), water (H2O), carbon monoxide (CO), and hydroxyl (OH) at signal-to-noise ratios exceeding 4, and retrieve their elemental abundances. We show that the Mg/Si, Fe/Mg, and Si/Fe ratios are consistent with stellar values, while the refractory-to-volatile ratio is enhanced by roughly a factor of 2. These findings demonstrate that giant-planet atmospheres can preserve stellar-like rock-forming ratios, providing an empirical validation of the stellar-proxy assumption that underpins planetary composition and formation models across exoplanet systems.