arXiv - PHYS - Earth and Planetary Astrophysics最新文献

{"title":"Updated forecast for TRAPPIST-1 times of transit for all seven exoplanets incorporating JWST data","authors":"Eric Agol, Natalie H. Allen, Björn Benneke, Laetitia Delrez, René Doyon, Elsa Ducrot, Néstor Espinoza, Amélie Gressier, David Lafrenière, Olivia Lim, Jacob Lustig-Yaeger, Caroline Piaulet-Ghorayeb, Michael Radica, Zafar Rustamkulov, Kristin S. Sotzen","doi":"arxiv-2409.11620","DOIUrl":"https://doi.org/arxiv-2409.11620","url":null,"abstract":"The TRAPPIST-1 system has been extensively observed with JWST in the\u0000near-infrared with the goal of measuring atmospheric transit transmission\u0000spectra of these temperate, Earth-sized exoplanets. A byproduct of these\u0000observations has been much more precise times of transit compared with prior\u0000available data from Spitzer, HST, or ground-based telescopes. In this note we\u0000use 23 new timing measurements of all seven planets in the near-infrared from\u0000five JWST observing programs to better forecast and constrain the future times\u0000of transit in this system. In particular, we note that the transit times of\u0000TRAPPIST-1h have drifted significantly from a prior published analysis by up to\u0000tens of minutes. Our newer forecast has a higher precision, with median\u0000statistical uncertainties ranging from 7-105 seconds during JWST Cycles 4 and\u00005. Our expectation is that this forecast will help to improve planning of\u0000future observations of the TRAPPIST-1 planets, whereas we postpone a full\u0000dynamical analysis to future work.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Drifts of the sub-stellar points of the TRAPPIST-1 planets","authors":"Revol Alexandre, Émeline Bolmont, Mariana Sastre, Gabriel Tobie, Anne-Sophie Libert, Mathilde Kervazo, Sergi Blanco-Cuaresma","doi":"arxiv-2409.12065","DOIUrl":"https://doi.org/arxiv-2409.12065","url":null,"abstract":"Accurate modeling of tidal interactions is crucial for interpreting recent\u0000JWST observations of the thermal emissions of TRAPPIST-1~b and c and for\u0000characterizing the surface conditions and potential habitability of the other\u0000planets in the system. Indeed, the rotation state of the planets, driven by\u0000tidal forces, significantly influences the heat redistribution regime. Due to\u0000their proximity to their host star and the estimated age of the system, the\u0000TRAPPIST-1 planets are commonly assumed to be in a synchronization state. In\u0000this work, we present the recent implementation of the co-planar tidal torque\u0000and forces equations within the formalism of Kaula in the N-body code\u0000Posidonius. This enables us to explore the hypothesis of synchronization using\u0000a tidal model well suited to rocky planets. We studied the rotational state of\u0000each planet by taking into account their multi-layer internal structure\u0000computed with the code Burnman. Simulations show that the TRAPPIST-1 planets\u0000are not perfectly synchronized but oscillate around the synchronization state.\u0000Planet-planet interactions lead to strong variations on the mean motion and\u0000tides fail to keep the spin synchronized with respect to the mean motion. As a\u0000result, the sub-stellar point of each planet experiences short oscillations and\u0000long-timescale drifts that lead the planets to achieve a synodic day with\u0000periods varying from $55$~years to $290$~years depending on the planet.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Probing the Possible Causes of the Transit Timing Variation for TrES-2b in TESS Era","authors":"Shraddha Biswas, D. Bisht, Ing-Guey Jiang, Devesh P. Sariya, Kaviya Parthasarathy","doi":"arxiv-2409.12069","DOIUrl":"https://doi.org/arxiv-2409.12069","url":null,"abstract":"Nowadays, transit timing variations (TTVs) are proving to be a very valuable\u0000tool in exoplanetary science to detect exoplanets by observing variations in\u0000transit times. To study the transit timing variation of the hot Jupiter,\u0000TrES-2b, we have combined 64 high-quality transit light curves from all seven\u0000sectors of NASA's Transiting Exoplanet Survey Satellite (TESS) along with 60\u0000best-quality light curves from the ground-based facility Exoplanet Transit\u0000Database (ETD) and 106 mid-transit times from the previous works. From the\u0000precise transit timing analysis, we have observed a significant improvement in\u0000the orbital ephemerides, but we did not detect any short period TTVs that might\u0000result from an additional body. The inability to detect short-term TTVs further\u0000motivates us to investigate long-term TTVs, which might be caused by orbital\u0000decay, apsidal precession, Applegate mechanism, and $R{phi}$mer effect and the\u0000orbital decay appeared to be a better explanation for the observed TTV with\u0000$Delta BIC$ = 4.32. The orbital period of the hot Jupiter TrES-2b appears to\u0000be shrinking at a rate of $-5.58 pm 1.81$ ms/yr. Assuming this decay is\u0000primarily caused by tidal dissipation within the host star, we have\u0000subsequently calculated the stellar tidal quality factor value to be 9900,\u0000which is 2 to 3 orders of magnitude smaller than the theoretically predicted\u0000values for other hot-Jupiter systems and its low value indicates more efficient\u0000tidal dissipation within the host star. Additional precise photometric and\u0000radial velocity observations are required to pinpoint the cause of the change\u0000in the orbital period.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"48 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Training Datasets Generation for Machine Learning: Application to Vision Based Navigation","authors":"Jérémy Lebreton, Ingo Ahrns, Roland Brochard, Christoph Haskamp, Matthieu Le Goff, Nicolas Menga, Nicolas Ollagnier, Ralf Regele, Francesco Capolupo, Massimo Casasco","doi":"arxiv-2409.11383","DOIUrl":"https://doi.org/arxiv-2409.11383","url":null,"abstract":"Vision Based Navigation consists in utilizing cameras as precision sensors\u0000for GNC after extracting information from images. To enable the adoption of\u0000machine learning for space applications, one of obstacles is the demonstration\u0000that available training datasets are adequate to validate the algorithms. The\u0000objective of the study is to generate datasets of images and metadata suitable\u0000for training machine learning algorithms. Two use cases were selected and a\u0000robust methodology was developed to validate the datasets including the ground\u0000truth. The first use case is in-orbit rendezvous with a man-made object: a\u0000mockup of satellite ENVISAT. The second use case is a Lunar landing scenario.\u0000Datasets were produced from archival datasets (Chang'e 3), from the laboratory\u0000at DLR TRON facility and at Airbus Robotic laboratory, from SurRender software\u0000high fidelity image simulator using Model Capture and from Generative\u0000Adversarial Networks. The use case definition included the selection of\u0000algorithms as benchmark: an AI-based pose estimation algorithm and a dense\u0000optical flow algorithm were selected. Eventually it is demonstrated that\u0000datasets produced with SurRender and selected laboratory facilities are\u0000adequate to train machine learning algorithms.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Self-oxidation of the atmospheres of rocky planets with implications for the origin of life","authors":"Anders JohansenUniversity of Copenhagen, Eloi CamprubiUniversity of Texas Rio Grande Valley, Elishevah van KootenUniversity of Copenhagen, Jens HoeijmakersLund University","doi":"arxiv-2409.11070","DOIUrl":"https://doi.org/arxiv-2409.11070","url":null,"abstract":"Rocky planets may acquire a primordial atmosphere by outgassing of volatiles\u0000from their magma ocean. The distribution of O between H$_2$O, CO and CO$_2$ in\u0000chemical equilibrium subsequently changes significantly with decreasing\u0000temperature. We explore here two chemical models: one where CH$_4$ and NH$_3$\u0000are assumed to be irrevocably destroyed by photolysis, and one where these\u0000molecules persist. In the first case, we show that CO cannot co-exist with\u0000H$_2$O, since CO oxidizes at low temperatures to form CO$_2$ and H$_2$. In both\u0000cases, H escapes from the thermosphere within a few ten million years by\u0000absorption of stellar XUV radiation. This escape drives an atmospheric\u0000self-oxidation process whereby rocky planet atmospheres become dominated by\u0000CO$_2$ and H$_2$O, regardless of their initial oxidation state at outgassing.\u0000HCN is considered a potential precursor of prebiotic compounds and RNA. Our\u0000oxidizing atmospheres are inefficient at producing HCN by lightning. Instead,\u0000we demonstrate that lightning-produced NO, which dissolves as nitrate in the\u0000oceans, and interplanetary dust particles may be the main sources of fixed\u0000nitrogen to emerging biospheres. Our results highlight the need for\u0000origin-of-life scenarios where the first metabolism fixes its C from CO$_2$,\u0000rather than from HCN and CO.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Impact of Icy Cometary 'Impacts' on Exoplanetary Atmospheres I: Tidally-Locked Terrestrial Exoplanets","authors":"Felix Sainsbury-Martinez, Catherine Walsh, Greg Cooke","doi":"arxiv-2409.11151","DOIUrl":"https://doi.org/arxiv-2409.11151","url":null,"abstract":"Impacts by rocky and icy bodies are thought to have played a key role in\u0000shaping the composition of solar system objects, including the Earth's\u0000habitability. Hence, it is likely that they play a similar role in exoplanetary\u0000systems. We investigate how an icy cometary impact affects the atmospheric\u0000chemistry, climate, and composition of an Earth-like, tidally-locked,\u0000terrestrial exoplanet, a prime target in the search for a habitable exoplanet\u0000beyond our solar system. We couple a cometary impact model which includes\u0000thermal ablation and pressure driven breakup with the 3D Earth System Model\u0000WACCM6/CESM2, and use this model to investigate the effects of the water and\u0000thermal energy delivery associated with an $R=2.5$ km pure water ice cometary\u0000impact on an Earth-like atmosphere. We find that water is the primary driver of\u0000longer timescale changes to the atmospheric chemistry and composition by acting\u0000as a source of opacity, cloud ice, and atmospheric hydrogen/oxygen. The water\u0000opacity drives heating at $sim5times10^{-4}$ bar, and cooling below, due to a\u0000decreased flux reaching the surface. The increase in atmospheric hydrogen and\u0000oxygen also drives an increase in the abundance of hydrogen/oxygen rich\u0000molecules, with the exception of ozone, whose column density decreases by\u0000$sim10%$. These atmospheric changes are potentially observable for $sim$ 1-2\u0000years post-impact, particularly those associated with cloud ice scattering.\u0000They also persist, albeit at a much reduced level, to our quasi-steady-state,\u0000suggesting that sustained bombardment or multiple large impacts have the\u0000potential to shape the composition and habitability of terrestrial exoplanets.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evolution of gas envelopes and outgassed atmospheres of rocky planets formed via pebble accretion","authors":"Piia Maria TombergUniversity of Copenhagen, Globe Institute, Anders JohansenUniversity of Copenhagen, Globe Institute","doi":"arxiv-2409.11005","DOIUrl":"https://doi.org/arxiv-2409.11005","url":null,"abstract":"We present here results of numerical simulations of the formation and early\u0000evolution of rocky planets through pebble accretion, with an with an emphasis\u0000on hydrogen envelope longevity and the composition of the outgassed atmosphere.\u0000We model planets with a range in mass from 0.1 to 5 Earth masses that orbit\u0000between 0.7 and 1.7 AU. The composition of the outgassed atmosphere is\u0000calculated with the partial pressure of free oxygen fit to geophysical models\u0000of magma ocean self-oxidation. XUV radiation powered photoevaporation is\u0000considered as the main driver of atmospheric escape. We model planets that\u0000remain below the pebble isolation mass and hence accrete tenuous envelopes\u0000only. We consider slow, medium or fast initial stellar rotation for the\u0000temporal evolution of the XUV flux. The loss of the envelope is a key event\u0000that allows the magma ocean to crystallise and outgas its bulk volatiles. The\u0000atmospheric composition of the majority of our simulated planets is dominated\u0000by CO$_2$. Our planets accrete a total of 11.6 Earth oceans of water, the\u0000majority of which enters the core. The hydrospheres of planets lighter than the\u0000Earth reach several times the mass of the Earth's modern oceans, while the\u0000hydrospheres of planets ranging from 1 to 3.5 Earth masses are comparable to\u0000those of our planet. However, planets of 4-5 Earth masses have smaller\u0000hydrospheres due to trapping of volatiles in their massive mantles. Overall,\u0000our simulations demonstrate that hydrogen envelopes are easily lost from rocky\u0000planets and that this envelope loss triggers the most primordial partitioning\u0000of volatiles between the solid mantle and the atmosphere.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"48 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal Evolution of Lava Planets","authors":"Mahesh Herath, Charles-Édouard Boukaré, Nicolas B. Cowan","doi":"arxiv-2409.11459","DOIUrl":"https://doi.org/arxiv-2409.11459","url":null,"abstract":"Rocky planets are thought to form with a magma ocean that quickly solidifies.\u0000The horizontal and vertical extent of this magma ocean depends on the interior\u0000thermal evolution of the planet, and possibly exogenous processes such as\u0000planet migration. We present a model for simulating the thermal history of\u0000tidally locked lava planets. We initiate the model with a completely molten\u0000mantle and evolve it for ten billion years. We adopt a fixed surface\u0000temperature of 3000 K for the irradiated day-side, but allow the night-side\u0000temperature to evolve along with the underlying layers. We simulate planets of\u0000radius 1.0$R_{oplus}$ and 1.5$R_{oplus}$ with different core mass fractions,\u0000although the latter does not significantly impact the thermal evolution. We\u0000confirm that the day-side magma ocean on these planets has a depth that depends\u0000on the planetary radius. The night-side, on the other hand, begins\u0000crystallizing within a few thousand years and completely solidifies within 800\u0000million years in the absence of substantial tidal heating or day-night heat\u0000transport. We show that a magma ocean can be sustained on the night-side of a\u0000lava planet if at least 20 per cent of absorbed stellar power is transmitted\u0000from the day-side to the night-side via magma currents. Such day-night\u0000transport could be sustained if the magma has a viscosity of $10^{-3}$ Pa s,\u0000which is plausible at these temperatures. Alternatively, the night-side could\u0000remain molten if the mush layer is tidally heated at the rate of $8 times\u000010^{-4}$ W/kg of mush, which is plausible for orbital eccentricities of $e > 7\u0000times 10^{-3}$. Night-side cooling is a runaway process, however: the magma\u0000becomes more viscous and the mush solidifies, reducing both day-night heat\u0000transport and tidal heating. Measurements of the night-sides of lava planets\u0000are therefore a sensitive probe of the thermal history of these planets.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterisation of TOI-406 as showcase of the THIRSTEE program: A 2-planet system straddling the M-dwarf density gap","authors":"G. Lacedelli, E. Pallè, R. Luque, C. Cadieux, J. M. Akana Murphy, F. Murgas, M. R. Zapatero Osorio, H. M. Tabernero, K. A. Collins, C. N. Watkins, A. L'Heureux, R. Doyon, D. Jankowski, G. Nowak, È. Artigau, N. M. Batalha, J. L. Bean, F. Bouchy, M. Brady, B. L. Canto Martins, I. Carleo, M. Cointepas, D. M. Conti, N. J. Cook, I. J. M. Crossfield, J. I. Gonzàlez Hernàndez, P. Lewin, N. Nari, L. D. Nielsen, J. Orell-Miquel, L. Parc, R. P. Schwarz, G. Srdoc, V. Van Eylen","doi":"arxiv-2409.11083","DOIUrl":"https://doi.org/arxiv-2409.11083","url":null,"abstract":"The exoplanet sub-Neptune population currently poses a conundrum. Are\u0000small-size planets volatile-rich cores without atmosphere, or are they rocky\u0000cores surrounded by H-He envelope? To test the different hypotheses from an\u0000observational point of view, a large sample of small-size planets with precise\u0000mass and radius measurements is the first necessary step. On top of that, much\u0000more information will likely be needed, including atmospheric characterisation\u0000and a demographic perspective on their bulk properties. We present the concept\u0000and strategy of THIRSTEE, a project which aims at shedding light on the\u0000composition of the sub-Neptune population across stellar types by increasing\u0000their number and improving the accuracy of bulk density measurements, as well\u0000as investigating their atmospheres and performing statistical, demographic\u0000analysis. We report the first results of the program, characterising a 2-planet\u0000system around the M dwarf TOI-406. We analyse TESS and ground-based photometry,\u0000together with ESPRESSO and NIRPS/HARPS RVs to derive the orbital parameters and\u0000investigate the internal composition of the 2 planets orbiting TOI-406, which\u0000have radii and masses of $R_b = 1.32 pm 0.12 R_{oplus}$, $M_b =\u00002.08_{-0.22}^{+0.23} M_{oplus}$ and $R_c = 2.08_{-0.15}^{+0.16} R_{oplus}$,\u0000$M_c = 6.57_{-0.90}^{+1.00} M_{oplus}$, and periods of $3.3$ and $13.2$ days,\u0000respectively. Planet b is consistent with an Earth-like composition, while\u0000planet c is compatible with multiple internal composition models, including\u0000volatile-rich planets without H/He atmospheres. The 2 planets are located in 2\u0000distinct regions in the mass-density diagram, supporting the existence of a\u0000density gap among small exoplanets around M dwarfs. With an equilibrium\u0000temperature of only 368 K, TOI-406 c stands up as a particularly interesting\u0000target for atmospheric characterisation with JWST in the low-temperature\u0000regime.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"54 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quartz Clouds in the Dayside Atmosphere of the Quintessential Hot Jupiter HD 189733 b","authors":"Julie Inglis, Natasha E. Batalha, Nikole K. Lewis, Tiffany Kataria, Heather A. Knutson, Brian M. Kilpatrick, Anna Gagnebin, Sagnick Mukherjee, Maria M. Pettyjohn, Ian J. M. Crossfield, Trevor O. Foote, David Grant, Gregory W. Henry, Maura Lally, Laura K. McKemmish, David K. Sing, Hannah R. Wakeford, Juan C. Zapata Trujillo, Robert T. Zellem","doi":"arxiv-2409.11395","DOIUrl":"https://doi.org/arxiv-2409.11395","url":null,"abstract":"Recent mid-infrared observations with JWST/MIRI have resulted in the first\u0000direct detections of absorption features from silicate clouds in the\u0000transmission spectra of two transiting exoplanets, WASP-17 b and WASP-107 b. In\u0000this paper, we measure the mid-infrared ($5-12$ $mu$m) dayside emission\u0000spectrum of the benchmark hot Jupiter HD 189733 b with MIRI LRS by combining\u0000data from two secondary eclipse observations. We confirm the previous detection\u0000of H$_2$O absorption at 6.5 $mu$m from Spitzer/IRS and additionally detect\u0000H$_2$S as well as an absorption feature at 8.7 $mu$m in both secondary eclipse\u0000observations. The excess absorption at 8.7 $mu$m can be explained by the\u0000presence of small ($sim$0.01 $mu$m) grains of SiO$_2$[s] in the uppermost\u0000layers of HD 189733 b's dayside atmosphere. This is the first direct detection\u0000of silicate clouds in HD 189733 b's atmosphere, and the first detection of a\u0000distinct absorption feature from silicate clouds on the day side of any hot\u0000Jupiter. We find that models including SiO$_2$[s] are preferred by $6-7sigma$\u0000over clear models and those with other potential cloud species. The high\u0000altitude location of these silicate particles is best explained by formation in\u0000the hottest regions of HD 189733 b's dayside atmosphere near the substellar\u0000point. We additionally find that HD 189733 b's emission spectrum longward of 9\u0000$mu$m displays residual features not well captured by our current atmospheric\u0000models. When combined with other JWST observations of HD 189733 b's\u0000transmission and emission spectrum at shorter wavelengths, these observations\u0000will provide us with the most detailed picture to date of the atmospheric\u0000composition and cloud properties of this benchmark hot Jupiter.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}