Erica Bisesi, Giuseppe Murante, Antonello Provenzale, Lorenzo Biasiotti, Jost von Hardenberg, Stavro Ivanovski, Michele Maris, Sergio Monai, Laura Silva, Paolo Simonetti, Giovanni Vladilo
Vegetation can modify the planetary surface albedo via the Charney mechanism, as plants are usually darker than the bare surface of the continents. We updated ESTM (Earth-like Surface Temperature Model) to incorporate the presence, distribution and evolution of two dynamically competing vegetation types that resemble grasslands and trees (the latter in the double stages of life: adults and seedlings). The newly developed model was applied to estimate how the climate-vegetation system reaches equilibrium across different rocky planetary configurations, and to assess its impact on temperature and habitability. With respect to a world with bare granite continents, the effect of vegetation-albedo feedback is to increase the average surface temperature. Since grasses and trees exhibit different albedos, they affect temperature to different degrees. The ultimate impact on climate depends on the outcome of the competition between these vegetation types. The change in albedo due to vegetation extends the habitable zone and enhances the overall planetary habitability beyond its traditional outer edge. This effect is especially relevant for planets that have a larger extension of continents than Earth. For Earth, the semi-major axis d = 1.04 UA represents the turning point where vegetation enhances habitability from h = 0.0 to h = 0.485 (in the grass-dominance case), to h = 0.584 (in the case of coexistence between grasses and trees), and to h = 0.612 (in the tree-dominance case). This illustrates the transition from a snowball state to a planet with intermediate habitability at the outer edge of the circumstellar habitability zone.
植被可以通过查尔尼机制改变行星表面的反照率，因为植物通常比大陆裸露的表面更暗。我们更新了ESTM（类地表温度模型），将两种动态竞争植被类型的存在、分布和演化纳入其中，这两种植被类型类似于草地和树木（后者处于生命的两个阶段：成苗和幼苗）。新开发的模型被用于估算气候-植被系统如何在不同的岩石行星构型中达到平衡，并评估其对温度和可居住性的影响。由于草和树木的反照率不同，它们对温度的影响程度也不同。对气候的最终影响取决于这些植被类型之间竞争的结果。植被导致的反照率变化扩大了宜居带，使行星的整体宜居性超出了其传统的外缘。这种效应对于大陆延伸范围大于地球的行星尤为重要。对于地球来说，半长轴 d = 1.04 UA 代表着一个转折点，在这个转折点上，植被将宜居性从 h = 0.0 提升到 h = 0.485（在草主导的情况下）、h = 0.584（在草与树共存的情况下）和 h = 0.612（在树主导的情况下）。这说明了在星周宜居带外缘从雪球状态向中等宜居性行星的过渡。
{"title":"Impact of vegetation albedo on the habitability of Earth-like exoplanets","authors":"Erica Bisesi, Giuseppe Murante, Antonello Provenzale, Lorenzo Biasiotti, Jost von Hardenberg, Stavro Ivanovski, Michele Maris, Sergio Monai, Laura Silva, Paolo Simonetti, Giovanni Vladilo","doi":"arxiv-2409.01746","DOIUrl":"https://doi.org/arxiv-2409.01746","url":null,"abstract":"Vegetation can modify the planetary surface albedo via the Charney mechanism,\u0000as plants are usually darker than the bare surface of the continents. We\u0000updated ESTM (Earth-like Surface Temperature Model) to incorporate the\u0000presence, distribution and evolution of two dynamically competing vegetation\u0000types that resemble grasslands and trees (the latter in the double stages of\u0000life: adults and seedlings). The newly developed model was applied to estimate\u0000how the climate-vegetation system reaches equilibrium across different rocky\u0000planetary configurations, and to assess its impact on temperature and\u0000habitability. With respect to a world with bare granite continents, the effect\u0000of vegetation-albedo feedback is to increase the average surface temperature.\u0000Since grasses and trees exhibit different albedos, they affect temperature to\u0000different degrees. The ultimate impact on climate depends on the outcome of the\u0000competition between these vegetation types. The change in albedo due to\u0000vegetation extends the habitable zone and enhances the overall planetary\u0000habitability beyond its traditional outer edge. This effect is especially\u0000relevant for planets that have a larger extension of continents than Earth. For\u0000Earth, the semi-major axis d = 1.04 UA represents the turning point where\u0000vegetation enhances habitability from h = 0.0 to h = 0.485 (in the\u0000grass-dominance case), to h = 0.584 (in the case of coexistence between grasses\u0000and trees), and to h = 0.612 (in the tree-dominance case). This illustrates the\u0000transition from a snowball state to a planet with intermediate habitability at\u0000the outer edge of the circumstellar habitability zone.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204623","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}
M. C. D'Arpa, A. Saba, F. Borsa, L. Fossati, G. Micela, C. Di Maio, M. Stangret, G. Tripodo, L. Affer, A. S. Bonomo, S. Benatti, M. Brogi, V. Fardella, A. F. Lanza, G. Guilluy, J. Maldonado, G. Mantovan, V. Nascimbeni, L. Pino, G. Scandariato, D. Sicilia, A. Sozzetti, R. Spinelli, G. Andreuzzi, A. Bignamini, R. Claudi, S. Desidera, A. Ghedina, C. Knapic, V. Lorenzi
We analysed six primary transits of the ultra-hot Jupiter KELT-9,b obtained with the HARPS-N high-resolution spectrograph in the context of the Global Architecture of Planetary Systems (GAPS2) project, to characterise the atmosphere via single-line analysis. We extracted the transmission spectrum of each individual line by comparing the master out-of-transit spectrum with the in-transit spectra and computing the weighted average of the tomography in the planet reference frame. We corrected for the centre-to-limb variation and the Rossiter-McLaughlin effect by modelling the region of the star disc obscured by the planet during the transit and subtracting it from the master-out spectrum. We detected all six observable lines of the Balmer series within the HARPS-N wavelength range, from H$alpha$ to H$zeta$, with a significance exceeding 5$sigma$. We focussed on metal species, detecting Na I, Ca I, Ca II, Fe I, Fe II, Mg I, Ti II, Sc II, and Cr II lines. This is the first detection in the atmosphere of an exoplanet of H$epsilon$ and H$zeta$ lines, as well as of individual lines of Sc II and Cr II. Our detections are supported by a comparison with published synthetic transmission spectra of KELT-9b obtained accounting for non-local thermodynamic equilibrium effects. The results underline the presence of a systematic blueshift due to night-side to day-side winds. The single-line analysis allowed us not only to assess the presence of atomic species in the atmosphere of KELT-9 b, but also to further characterise the local stratification of the atmosphere. Coupling the height distribution of the detected species with the velocity shift retrieved, we acknowledged the height distribution of night-side to day-side winds. Moreover, the study of the rotational broadening of different species supports the prediction of a tidally locked planet rotating as a rigid body.
我们分析了在行星系统全球结构（GAPS2）项目中利用 HARPS-N 高分辨率光谱仪获得的超热木星 KELT-9 b 的六次主凌日，通过单线分析来描述其大气层的特征。我们通过比较主轨迹外光谱和轨迹内光谱，并计算行星参照系中层析成像的加权平均值，提取了每条单线的透射光谱。在HARPS-N波长范围内，从H$alpha$到H$zeta$，我们探测到了Balmer系列的所有六条可观测到的线，其重要程度超过了5$sigma$。我们重点研究了金属物种，探测到了 Na I、Ca I、Ca II、Fe I、Fe II、Mg I、Ti II、Sc II 和 Cr II 线。这是首次在系外行星的大气层中探测到H$epsilon$和H$zeta$线，以及Sc II和Cr II的个别线。我们的探测结果得到了与已发表的 KELT-9b 合成透射光谱的比较结果的支持，KELT-9b 的合成透射光谱是在考虑了非局部热力学平衡效应的情况下获得的。结果表明，从夜侧风到日侧风导致了系统性蓝移的存在。单线分析使我们不仅能够评估 KELT-9 b 大气层中原子物种的存在，还能进一步确定大气层局部分层的特征。将探测到的物种高度分布与检索到的速度偏移结合起来，我们确认了夜侧风与昼侧风的高度分布。此外，对不同种类的旋转展宽的研究支持了作为刚体旋转的潮汐锁定行星的预测。
{"title":"The GAPS programme at TNG LX Atmospheric characterisation of KELT-9 b via single-line analysis: Detection of six H I Balmer lines, Na I, Ca I, Ca II, Fe I, Fe II, Mg I, Ti II, Sc II, and Cr II","authors":"M. C. D'Arpa, A. Saba, F. Borsa, L. Fossati, G. Micela, C. Di Maio, M. Stangret, G. Tripodo, L. Affer, A. S. Bonomo, S. Benatti, M. Brogi, V. Fardella, A. F. Lanza, G. Guilluy, J. Maldonado, G. Mantovan, V. Nascimbeni, L. Pino, G. Scandariato, D. Sicilia, A. Sozzetti, R. Spinelli, G. Andreuzzi, A. Bignamini, R. Claudi, S. Desidera, A. Ghedina, C. Knapic, V. Lorenzi","doi":"arxiv-2409.01779","DOIUrl":"https://doi.org/arxiv-2409.01779","url":null,"abstract":"We analysed six primary transits of the ultra-hot Jupiter KELT-9,b obtained\u0000with the HARPS-N high-resolution spectrograph in the context of the Global\u0000Architecture of Planetary Systems (GAPS2) project, to characterise the\u0000atmosphere via single-line analysis. We extracted the transmission spectrum of\u0000each individual line by comparing the master out-of-transit spectrum with the\u0000in-transit spectra and computing the weighted average of the tomography in the\u0000planet reference frame. We corrected for the centre-to-limb variation and the\u0000Rossiter-McLaughlin effect by modelling the region of the star disc obscured by\u0000the planet during the transit and subtracting it from the master-out spectrum.\u0000We detected all six observable lines of the Balmer series within the HARPS-N\u0000wavelength range, from H$alpha$ to H$zeta$, with a significance exceeding\u00005$sigma$. We focussed on metal species, detecting Na I, Ca I, Ca II, Fe I, Fe\u0000II, Mg I, Ti II, Sc II, and Cr II lines. This is the first detection in the\u0000atmosphere of an exoplanet of H$epsilon$ and H$zeta$ lines, as well as of\u0000individual lines of Sc II and Cr II. Our detections are supported by a\u0000comparison with published synthetic transmission spectra of KELT-9b obtained\u0000accounting for non-local thermodynamic equilibrium effects. The results\u0000underline the presence of a systematic blueshift due to night-side to day-side\u0000winds. The single-line analysis allowed us not only to assess the presence of\u0000atomic species in the atmosphere of KELT-9 b, but also to further characterise\u0000the local stratification of the atmosphere. Coupling the height distribution of\u0000the detected species with the velocity shift retrieved, we acknowledged the\u0000height distribution of night-side to day-side winds. Moreover, the study of the\u0000rotational broadening of different species supports the prediction of a tidally\u0000locked planet rotating as a rigid body.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204622","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}
Hazardous asteroid has been one of the concerns for humankind as fallen asteroid on earth could cost a huge impact on the society.Monitoring these objects could help predict future impact events, but such efforts are hindered by the large numbers of objects that pass in the Earth's vicinity. The aim of this project is to use machine learning and deep learning to accurately classify hazardous asteroids. A total of ten methods which consist of five machine learning algorithms and five deep learning models are trained and evaluated to find the suitable model that solves the issue. We experiment on two datasets, one from Kaggle and one we extracted from a web service called NeoWS which is a RESTful web service from NASA that provides information about near earth asteroids, it updates every day. In overall, the model is tested on two datasets with different features to find the most accurate model to perform the classification.
{"title":"Hazardous Asteroids Classification","authors":"Thai Duy Quy, Alvin Buana, Josh Lee, Rakha Asyrofi","doi":"arxiv-2409.02150","DOIUrl":"https://doi.org/arxiv-2409.02150","url":null,"abstract":"Hazardous asteroid has been one of the concerns for humankind as fallen\u0000asteroid on earth could cost a huge impact on the society.Monitoring these\u0000objects could help predict future impact events, but such efforts are hindered\u0000by the large numbers of objects that pass in the Earth's vicinity. The aim of\u0000this project is to use machine learning and deep learning to accurately\u0000classify hazardous asteroids. A total of ten methods which consist of five\u0000machine learning algorithms and five deep learning models are trained and\u0000evaluated to find the suitable model that solves the issue. We experiment on\u0000two datasets, one from Kaggle and one we extracted from a web service called\u0000NeoWS which is a RESTful web service from NASA that provides information about\u0000near earth asteroids, it updates every day. In overall, the model is tested on\u0000two datasets with different features to find the most accurate model to perform\u0000the classification.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204620","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}
Uranus and Neptune have atmospheres dominated by molecular hydrogen and helium. In the upper troposphere, methane is the third main molecule and condenses, yielding a vertical gradient in CH4. This condensable species being heavier than H2 and He, the resulting change in mean molecular weight due to condensation comes as a factor countering dry and moist convection. As observations also show latitudinal variations in methane abundance, one can expect different vertical gradients from one latitude to another. In this paper, we investigate the impact of this methane vertical gradient on the atmospheric regimes, especially on the formation and inhibition of moist convective storms in the troposphere of ice giants. We develop a 3D cloud-resolving model to simulate convective processes. Using our simulations, we conclude that typical velocities of dry convection in the deep atmosphere are rather low (of the order of 1 m/s) but sufficient to sustain upward methane transport, and that moist convection at methane condensation level is strongly inhibited. Previous studies derived an analytical criterion on the methane vapor amount above which moist convection should be inhibited. We first validate this analytical criterion numerically. We then show that the critical methane abundance governs the inhibition and formation of moist convective storms, and we conclude that the intensity and intermittency of these storms should depend on the methane abundance and saturation. In ice giants, dry convection is weak, and moist convection is strongly inhibited. However, when enough methane is transported upwards, through dry convection and turbulent diffusion, sporadic moist convective storms can form. These storms should be more frequent on Neptune than on Uranus, because of Neptune's internal heat flow. Our results can explain the observed sporadicity of clouds in ice giants.
{"title":"Storms and convection on Uranus and Neptune: impact of methane abundance revealed by a 3D cloud-resolving model","authors":"Noé Clément, Jérémy Leconte, Aymeric Spiga, Sandrine Guerlet, Franck Selsis, Gwenaël Milcareck, Lucas Teinturier, Thibault Cavalié, Raphaël Moreno, Emmanuel Lellouch, Óscar Carrión-González","doi":"arxiv-2409.02091","DOIUrl":"https://doi.org/arxiv-2409.02091","url":null,"abstract":"Uranus and Neptune have atmospheres dominated by molecular hydrogen and\u0000helium. In the upper troposphere, methane is the third main molecule and\u0000condenses, yielding a vertical gradient in CH4. This condensable species being\u0000heavier than H2 and He, the resulting change in mean molecular weight due to\u0000condensation comes as a factor countering dry and moist convection. As\u0000observations also show latitudinal variations in methane abundance, one can\u0000expect different vertical gradients from one latitude to another. In this\u0000paper, we investigate the impact of this methane vertical gradient on the\u0000atmospheric regimes, especially on the formation and inhibition of moist\u0000convective storms in the troposphere of ice giants. We develop a 3D\u0000cloud-resolving model to simulate convective processes. Using our simulations,\u0000we conclude that typical velocities of dry convection in the deep atmosphere\u0000are rather low (of the order of 1 m/s) but sufficient to sustain upward methane\u0000transport, and that moist convection at methane condensation level is strongly\u0000inhibited. Previous studies derived an analytical criterion on the methane\u0000vapor amount above which moist convection should be inhibited. We first\u0000validate this analytical criterion numerically. We then show that the critical\u0000methane abundance governs the inhibition and formation of moist convective\u0000storms, and we conclude that the intensity and intermittency of these storms\u0000should depend on the methane abundance and saturation. In ice giants, dry\u0000convection is weak, and moist convection is strongly inhibited. However, when\u0000enough methane is transported upwards, through dry convection and turbulent\u0000diffusion, sporadic moist convective storms can form. These storms should be\u0000more frequent on Neptune than on Uranus, because of Neptune's internal heat\u0000flow. Our results can explain the observed sporadicity of clouds in ice giants.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204621","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}
Trustless tracking of Resident Space Objects (RSOs) is crucial for Space Situational Awareness (SSA), especially during adverse situations. The importance of transparent SSA cannot be overstated, as it is vital for ensuring space safety and security. In an era where RSO location information can be easily manipulated, the risk of RSOs being used as weapons is a growing concern. The Tracking Data Message (TDM) is a standardized format for broadcasting RSO observations. However, the varying quality of observations from diverse sensors poses challenges to SSA reliability. While many countries operate space assets, relatively few have SSA capabilities, making it crucial to ensure the accuracy and reliability of the data. Current practices assume complete trust in the transmitting party, leaving SSA capabilities vulnerable to adversarial actions such as spoofing TDMs. This work introduces a trustless mechanism for TDM validation and verification using deep learning over blockchain. By leveraging the trustless nature of blockchain, our approach eliminates the need for a central authority, establishing consensus-based truth. We propose a state-of-the-art, transformer-based orbit propagator that outperforms traditional methods like SGP4, enabling cross-validation of multiple observations for a single RSO. This deep learning-based transformer model can be distributed over a blockchain, allowing interested parties to host a node that contains a part of the distributed deep learning model. Our system comprises decentralised observers and validators within a Proof of Stake (PoS) blockchain. Observers contribute TDM data along with a stake to ensure honesty, while validators run the propagation and validation algorithms. The system rewards observers for contributing verified TDMs and penalizes those submitting unverifiable data.
{"title":"On-chain Validation of Tracking Data Messages (TDM) Using Distributed Deep Learning on a Proof of Stake (PoS) Blockchain","authors":"Yasir Latif, Anirban Chowdhury, Samya Bagchi","doi":"arxiv-2409.01614","DOIUrl":"https://doi.org/arxiv-2409.01614","url":null,"abstract":"Trustless tracking of Resident Space Objects (RSOs) is crucial for Space\u0000Situational Awareness (SSA), especially during adverse situations. The\u0000importance of transparent SSA cannot be overstated, as it is vital for ensuring\u0000space safety and security. In an era where RSO location information can be\u0000easily manipulated, the risk of RSOs being used as weapons is a growing\u0000concern. The Tracking Data Message (TDM) is a standardized format for\u0000broadcasting RSO observations. However, the varying quality of observations\u0000from diverse sensors poses challenges to SSA reliability. While many countries\u0000operate space assets, relatively few have SSA capabilities, making it crucial\u0000to ensure the accuracy and reliability of the data. Current practices assume\u0000complete trust in the transmitting party, leaving SSA capabilities vulnerable\u0000to adversarial actions such as spoofing TDMs. This work introduces a trustless\u0000mechanism for TDM validation and verification using deep learning over\u0000blockchain. By leveraging the trustless nature of blockchain, our approach\u0000eliminates the need for a central authority, establishing consensus-based\u0000truth. We propose a state-of-the-art, transformer-based orbit propagator that\u0000outperforms traditional methods like SGP4, enabling cross-validation of\u0000multiple observations for a single RSO. This deep learning-based transformer\u0000model can be distributed over a blockchain, allowing interested parties to host\u0000a node that contains a part of the distributed deep learning model. Our system\u0000comprises decentralised observers and validators within a Proof of Stake (PoS)\u0000blockchain. Observers contribute TDM data along with a stake to ensure honesty,\u0000while validators run the propagation and validation algorithms. The system\u0000rewards observers for contributing verified TDMs and penalizes those submitting\u0000unverifiable data.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204630","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}
Edward M. Bryant, Daniel Bayliss, Joel D. Hartman, Elyar Sedaghati, Melissa J. Hobson, Andrés Jordán, Rafael Brahm, Gaspar Á. Bakos, Jose Manuel Almenara, Khalid Barkaoui, Xavier Bonfils, Marion Cointepas, Karen A. Collins, Georgina Dransfield, Phil Evans, Michaël Gillon, Emmanuël Jehin, Felipe Murgas, Francisco J. Pozuelos, Richard P. Schwarz, Mathilde Timmermans, Cristilyn N. Watkins, Anaël Wünsche, R. Paul Butler, Jeffrey D. Crane, Steve Shectman, Johanna K. Teske, David Charbonneau, Zahra Essack, Jon M. Jenkins, Hannah M. Lewis, Sara Seager, Eric B. Ting, Joshua N. Winn
Short-period gas giant planets have been shown to be significantly rarer for host stars less massive than the Sun. We report the discovery of two transiting giant planets - TOI-2379 b and TOI-2384 b - with low-mass (early M) host stars. Both planets were detected using TESS photometry and for both the transit signal was validated using ground based photometric facilities. We confirm the planetary nature of these companions and measure their masses using radial velocity observations. We find that TOI-2379 b has an orbital period of 5.469 d and a mass and radius of $5.76pm0.20$ M$_{J}$ and $1.046pm0.023$ R$_{J}$ and TOI-2384 b has an orbital period of 2.136 d and a mass and radius of $1.966pm0.059$ M$_{J}$ and $1.025pm0.021$ R$_{J}$. TOI-2379 b and TOI-2384 b have the highest and third highest planet-to-star mass ratios respectively out of all transiting exoplanets with a low-mass host star, placing them uniquely among the population of known exoplanets and making them highly important pieces of the puzzle for understanding the extremes of giant planet formation.
{"title":"TOI-2379 b and TOI-2384 b: two super-Jupiter mass planets transiting low-mass host stars","authors":"Edward M. Bryant, Daniel Bayliss, Joel D. Hartman, Elyar Sedaghati, Melissa J. Hobson, Andrés Jordán, Rafael Brahm, Gaspar Á. Bakos, Jose Manuel Almenara, Khalid Barkaoui, Xavier Bonfils, Marion Cointepas, Karen A. Collins, Georgina Dransfield, Phil Evans, Michaël Gillon, Emmanuël Jehin, Felipe Murgas, Francisco J. Pozuelos, Richard P. Schwarz, Mathilde Timmermans, Cristilyn N. Watkins, Anaël Wünsche, R. Paul Butler, Jeffrey D. Crane, Steve Shectman, Johanna K. Teske, David Charbonneau, Zahra Essack, Jon M. Jenkins, Hannah M. Lewis, Sara Seager, Eric B. Ting, Joshua N. Winn","doi":"arxiv-2409.01239","DOIUrl":"https://doi.org/arxiv-2409.01239","url":null,"abstract":"Short-period gas giant planets have been shown to be significantly rarer for\u0000host stars less massive than the Sun. We report the discovery of two transiting\u0000giant planets - TOI-2379 b and TOI-2384 b - with low-mass (early M) host stars.\u0000Both planets were detected using TESS photometry and for both the transit\u0000signal was validated using ground based photometric facilities. We confirm the\u0000planetary nature of these companions and measure their masses using radial\u0000velocity observations. We find that TOI-2379 b has an orbital period of 5.469 d\u0000and a mass and radius of $5.76pm0.20$ M$_{J}$ and $1.046pm0.023$ R$_{J}$ and\u0000TOI-2384 b has an orbital period of 2.136 d and a mass and radius of\u0000$1.966pm0.059$ M$_{J}$ and $1.025pm0.021$ R$_{J}$. TOI-2379 b and TOI-2384 b\u0000have the highest and third highest planet-to-star mass ratios respectively out\u0000of all transiting exoplanets with a low-mass host star, placing them uniquely\u0000among the population of known exoplanets and making them highly important\u0000pieces of the puzzle for understanding the extremes of giant planet formation.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204624","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}
F. Liebing, S. V. Jeffers, P. Gorrini, C. A. Haswell, S. Dreizler, J. R. Barnes, C. Hartogh, V. Koseleva, F. Del Sordo, P. J. Amado, J. A. Caballero, M. J. López-González, N. Morales, A. Reiners, I. Ribas, A. Quirrenbach, E. Rodríguez, L. Tal-Or, Y. Tsapras
Aims. Using HARPS spectroscopic data obtained by the RedDots campaign, as well as archival data from HARPS and CARMENES, supplemented with ASH2 and T90 photometry, we aim to search for additional planets around the three M dwarfs GJ 832, GJ 674, and Ross 128. We also aim to determine limits on possible undetected, habitable planets. We investigate (i) the reliability of the recovered orbital eccentricities and (ii) the reliability of Bayesian evidence as a diagnostic for selecting the best model. Methods. We employed Markov-chain Monte Carlo, nested sampling, and Gaussian process (GP) analyses to fit a total of 20 different models. We used the residuals to create grids for injection-recovery simulations to obtain detection limits on potentially undiscovered planets. Results. Our refined orbital elements for GJ 832 b, GJ 674 b, and Ross 128 b confirm (GJ 832, GJ 674) or increase (Ross 128) prior eccentricity determinations. No additional planets were found in any of the systems. The detection limits obtained for all three systems are between 30 and 50 cm/s for orbital periods in the range of 1 to 10 000 days. Using N-body simulations, we find that undiscovered secondary planets are unlikely (Ross 128) or incapable (GJ 674) of having caused the observed eccentricities of the known planets. We find that the eccentricity of GJ 832 b is not significantly different from zero. Conclusions. GJ 832 b, GJ 674 b, and Ross 128 b retain their status as hosting lonely and (for the latter two) eccentric planets. Finally, our results show that Bayesian evidence, when used in conjunction with GP, is not a robust diagnostic for selecting the best model in cases of low-activity stars. In such cases, we advise an inspection of the shapes of the posterior distributions and to ensure that relevant simulations are performed to assess the validity of the perceived best model.
目的。利用RedDots活动获得的HARPS光谱数据，以及HARPS和CARMENES的档案数据，辅以ASH2和T90光度计，我们的目标是在三颗M矮星GJ 832、GJ 674和Ross 128周围寻找更多的行星。我们还旨在确定可能未探测到的宜居行星的极限。我们研究了（i）发现的轨道偏心率的可靠性和（ii）贝叶斯证据作为选择最佳模型的诊断方法的可靠性。方法。我们采用马尔可夫链蒙特卡洛、嵌套采样和高斯过程（GP）分析方法拟合了20个不同的模型。我们利用这些剩余模型创建了注入-回收模拟网格，以获得潜在未发现行星的探测极限。结果。我们对 GJ 832 b、GJ 674 b 和 Ross 128 b 的改进轨道元素证实了（GJ 832、GJ 674）或增加了（Ross 128）先前的偏心率确定值。在所有这些星系中都没有发现额外的行星。所有三个系统的探测极限都在 30 到 50 厘米/秒之间，轨道周期在 1 到 10 000 天之间。通过N-体模拟，我们发现未发现的次级行星不太可能（Ross 128）或不可能（GJ 674）造成所观测到的已知行星的偏心率。我们发现 GJ 832 b 的偏心率与零相差不大。结论。GJ 832 b、GJ 674 b和Ross 128 b仍然是孤星和偏心行星（后两者）的宿主。最后，我们的研究结果表明，贝叶斯证据在与GP结合使用时，并不是在低活动性恒星情况下选择最佳模型的可靠诊断方法。在这种情况下，我们建议检查后验分布的形状，并确保进行相关模拟，以评估所认为的最佳模型的有效性。
{"title":"RedDots: Limits on habitable and undetected planets orbiting nearby stars GJ 832, GJ 674, and Ross 128","authors":"F. Liebing, S. V. Jeffers, P. Gorrini, C. A. Haswell, S. Dreizler, J. R. Barnes, C. Hartogh, V. Koseleva, F. Del Sordo, P. J. Amado, J. A. Caballero, M. J. López-González, N. Morales, A. Reiners, I. Ribas, A. Quirrenbach, E. Rodríguez, L. Tal-Or, Y. Tsapras","doi":"arxiv-2409.01173","DOIUrl":"https://doi.org/arxiv-2409.01173","url":null,"abstract":"Aims. Using HARPS spectroscopic data obtained by the RedDots campaign, as\u0000well as archival data from HARPS and CARMENES, supplemented with ASH2 and T90\u0000photometry, we aim to search for additional planets around the three M dwarfs\u0000GJ 832, GJ 674, and Ross 128. We also aim to determine limits on possible\u0000undetected, habitable planets. We investigate (i) the reliability of the\u0000recovered orbital eccentricities and (ii) the reliability of Bayesian evidence\u0000as a diagnostic for selecting the best model. Methods. We employed Markov-chain Monte Carlo, nested sampling, and Gaussian\u0000process (GP) analyses to fit a total of 20 different models. We used the\u0000residuals to create grids for injection-recovery simulations to obtain\u0000detection limits on potentially undiscovered planets. Results. Our refined orbital elements for GJ 832 b, GJ 674 b, and Ross 128 b\u0000confirm (GJ 832, GJ 674) or increase (Ross 128) prior eccentricity\u0000determinations. No additional planets were found in any of the systems. The\u0000detection limits obtained for all three systems are between 30 and 50 cm/s for\u0000orbital periods in the range of 1 to 10 000 days. Using N-body simulations, we\u0000find that undiscovered secondary planets are unlikely (Ross 128) or incapable\u0000(GJ 674) of having caused the observed eccentricities of the known planets. We\u0000find that the eccentricity of GJ 832 b is not significantly different from\u0000zero. Conclusions. GJ 832 b, GJ 674 b, and Ross 128 b retain their status as\u0000hosting lonely and (for the latter two) eccentric planets. Finally, our results\u0000show that Bayesian evidence, when used in conjunction with GP, is not a robust\u0000diagnostic for selecting the best model in cases of low-activity stars. In such\u0000cases, we advise an inspection of the shapes of the posterior distributions and\u0000to ensure that relevant simulations are performed to assess the validity of the\u0000perceived best model.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204626","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}
Tanguy Bertrand, François Forget, Emmanuel Lellouch
Triton and Pluto are believed to share a common origin, both forming initially in the Kuiper Belt but Triton being later captured by Neptune. Both objects display similar sizes, densities, and atmospheric and surface ice composition, with the presence of volatile ices N2, CH4 and CO. Yet their appearance, including their surface albedo and ice distribution strongly differ. What can explain these different appearances? A first disparity is that Triton is experiencing significant tidal heating due to its orbit around Neptune, with subsequent resurfacing and a relatively flat surface, while Pluto is not tidally activated and displays a pronounced topography. Here we present long-term volatile transport simulations of Pluto and Triton, using the same initial conditions and volatile inventory, but with the known orbit and rotation of each object. The model reproduces, to first order, the observed volatile ice surface distribution on Pluto and Triton. Our results unambiguously demonstrate that obliquity is the main driver of the differences in surface appearance and in climate properties on Pluto and Triton, and give further support to the hypothesis that both objects had a common origin followed by a different dynamical history.
{"title":"Twin Worlds, Divergent Fates: How Obliquity has differently shaped Pluto's and Triton's landscapes and climates","authors":"Tanguy Bertrand, François Forget, Emmanuel Lellouch","doi":"arxiv-2409.01122","DOIUrl":"https://doi.org/arxiv-2409.01122","url":null,"abstract":"Triton and Pluto are believed to share a common origin, both forming\u0000initially in the Kuiper Belt but Triton being later captured by Neptune. Both\u0000objects display similar sizes, densities, and atmospheric and surface ice\u0000composition, with the presence of volatile ices N2, CH4 and CO. Yet their\u0000appearance, including their surface albedo and ice distribution strongly\u0000differ. What can explain these different appearances? A first disparity is that\u0000Triton is experiencing significant tidal heating due to its orbit around\u0000Neptune, with subsequent resurfacing and a relatively flat surface, while Pluto\u0000is not tidally activated and displays a pronounced topography. Here we present\u0000long-term volatile transport simulations of Pluto and Triton, using the same\u0000initial conditions and volatile inventory, but with the known orbit and\u0000rotation of each object. The model reproduces, to first order, the observed\u0000volatile ice surface distribution on Pluto and Triton. Our results\u0000unambiguously demonstrate that obliquity is the main driver of the differences\u0000in surface appearance and in climate properties on Pluto and Triton, and give\u0000further support to the hypothesis that both objects had a common origin\u0000followed by a different dynamical history.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"50 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204627","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}
Varghese Reji, Shubham Kanodia, Joe Ninan, Caleb I. Cañas, Jessica Libby-Roberts, Andrea S. J. Lin, Arvind F Gupta, Tera N. Sewaby, Alexander Larsen, Henry A. Kobulnicky, Philip I. Choi, Nez Evans, Sage Santomenna, Isabelle Winnick, Larry Yu, Jaime A. Alvarado-Montes, Chad Bender, Lia Marta Bernabò, Cullen H. Blake, William D. Cochran, Scott A. Diddams, Samuel Halverson, Te Han, Fred Hearty, Sarah E. Logsdon, Suvrath Mahadevan, Andrew Monson, Michael McElwain, Paul Robertson, Devendra Ojha, Arpita Roy, Christian Schwab, Gudmundur Stefansson, Jason Wright
We present the discovery of a low-density planet transiting TOI-5688 A b, a high-metallicity M2V star. This planet was discovered as part of the search for transiting giant planets ($R gtrsim8$ M$_oplus$) through the Searching for GEMS (Giant Exoplanets around M-dwarf Stars) survey. The planet TOI-5688 A b was discovered with the Transiting Exoplanet Survey Satellite (TESS), and characterized with ground-based transits from Red Buttes Observatory (RBO), the Table Mountain Observatory of Pomona College, and radial velocity (RV) measurements with the Habitable-Zone Planet Finder (HPF) on the 10 m Hobby Eberly Telescope (HET) and NEID on the WIYN 3.5 m telescope. From the joint fit of transit and RV data, the mass of the planet is $124pm24$ M$_oplus$ and the radius is $10.4pm0.7$ R$_oplus$. This planet has a density of $0.61^{+0.20}_{-0.15}$ g/cm${}^3$, and is on a $sim2.95$ day orbit around its host star. The spectroscopic and photometric analysis of the host star TOI-5688 A shows that it is a high metallicity ([Fe/H] $ = 0.47pm0.16$ dex) M2V star, favoring the core-accretion formation pathway as the likely formation scenario for this planet. In this paper, we analyze potential mechanisms of planet formation in the context of the formation of TOI-5688 A b. Additionally, observations with Gaia suggest the presence of a wide-separation binary companion, TOI-5688 B, which has a projected separation of $sim5"$ (1110 AU) and is an M4V. This makes TOI-5688 A b part of a growing number of GEMS in wide-separation binary systems.
{"title":"Searching for GEMS: TOI-5688 A b, a low-density giant orbiting a high-metallicity early M-dwarf","authors":"Varghese Reji, Shubham Kanodia, Joe Ninan, Caleb I. Cañas, Jessica Libby-Roberts, Andrea S. J. Lin, Arvind F Gupta, Tera N. Sewaby, Alexander Larsen, Henry A. Kobulnicky, Philip I. Choi, Nez Evans, Sage Santomenna, Isabelle Winnick, Larry Yu, Jaime A. Alvarado-Montes, Chad Bender, Lia Marta Bernabò, Cullen H. Blake, William D. Cochran, Scott A. Diddams, Samuel Halverson, Te Han, Fred Hearty, Sarah E. Logsdon, Suvrath Mahadevan, Andrew Monson, Michael McElwain, Paul Robertson, Devendra Ojha, Arpita Roy, Christian Schwab, Gudmundur Stefansson, Jason Wright","doi":"arxiv-2409.01371","DOIUrl":"https://doi.org/arxiv-2409.01371","url":null,"abstract":"We present the discovery of a low-density planet transiting TOI-5688 A b, a\u0000high-metallicity M2V star. This planet was discovered as part of the search for\u0000transiting giant planets ($R gtrsim8$ M$_oplus$) through the Searching for\u0000GEMS (Giant Exoplanets around M-dwarf Stars) survey. The planet TOI-5688 A b\u0000was discovered with the Transiting Exoplanet Survey Satellite (TESS), and\u0000characterized with ground-based transits from Red Buttes Observatory (RBO), the\u0000Table Mountain Observatory of Pomona College, and radial velocity (RV)\u0000measurements with the Habitable-Zone Planet Finder (HPF) on the 10 m Hobby\u0000Eberly Telescope (HET) and NEID on the WIYN 3.5 m telescope. From the joint fit\u0000of transit and RV data, the mass of the planet is $124pm24$ M$_oplus$ and the\u0000radius is $10.4pm0.7$ R$_oplus$. This planet has a density of\u0000$0.61^{+0.20}_{-0.15}$ g/cm${}^3$, and is on a $sim2.95$ day orbit around its\u0000host star. The spectroscopic and photometric analysis of the host star TOI-5688\u0000A shows that it is a high metallicity ([Fe/H] $ = 0.47pm0.16$ dex) M2V star,\u0000favoring the core-accretion formation pathway as the likely formation scenario\u0000for this planet. In this paper, we analyze potential mechanisms of planet\u0000formation in the context of the formation of TOI-5688 A b. Additionally,\u0000observations with Gaia suggest the presence of a wide-separation binary\u0000companion, TOI-5688 B, which has a projected separation of $sim5\"$ (1110 AU)\u0000and is an M4V. This makes TOI-5688 A b part of a growing number of GEMS in\u0000wide-separation binary systems.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204625","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}
A significant proportion of exoplanets have been detected with highly tilted or even polar orbits relative to their host stars' equatorial planes. These unusual orbital configurations are often linked to post-disk secular interactions among multiple bodies. However, many aspects remain elusive. In this study, we investigate the role of disk-induced spin-orbit misalignments in shaping architecture of multi-planet systems, taking into account the combined effect of the host star's oblateness and the full-space disk potential. We demonstrate that large mutual planetary inclinations can arise from a saddle-center bifurcation occurring during the photoevaporation of the disk. This bifurcation triggers an instant, non-adiabatic transition in the planet's libration. Following this process, the orbital evolution diverges into several distinct patterns. Notably, in scenarios involving a near-polar primordial misalignment, the orbit, consistently librating about a coplanar equilibrium axis, can be captured by an orthogonal equilibrium during the decay of the stellar oblateness. However, the orbit will be eventually recaptured by the coplanar equilibrium, aligned or anti-aligned with the orientation of the outer orbit, resulting in either a prograde or retrograde inner-outer orbit configuration. Additionally, general relativity contributes to maintaining eccentricity stability within these dynamic scenarios. Through the proposed mechanism, we can provide a plausible explanation for the unique, near-perpendicular and likely retrograde orbit architecture observed in the HD 3167 system, enhancing our understanding of exoplanetary system dynamics.
{"title":"Misaligned Disk and Stellar Oblateness Driven Sculpting of Exoplanetary Systems: Origin of Perpendicular Orbits in HD 3167","authors":"Tao Fu, Yue Wang","doi":"arxiv-2409.00506","DOIUrl":"https://doi.org/arxiv-2409.00506","url":null,"abstract":"A significant proportion of exoplanets have been detected with highly tilted\u0000or even polar orbits relative to their host stars' equatorial planes. These\u0000unusual orbital configurations are often linked to post-disk secular\u0000interactions among multiple bodies. However, many aspects remain elusive. In\u0000this study, we investigate the role of disk-induced spin-orbit misalignments in\u0000shaping architecture of multi-planet systems, taking into account the combined\u0000effect of the host star's oblateness and the full-space disk potential. We\u0000demonstrate that large mutual planetary inclinations can arise from a\u0000saddle-center bifurcation occurring during the photoevaporation of the disk.\u0000This bifurcation triggers an instant, non-adiabatic transition in the planet's\u0000libration. Following this process, the orbital evolution diverges into several\u0000distinct patterns. Notably, in scenarios involving a near-polar primordial\u0000misalignment, the orbit, consistently librating about a coplanar equilibrium\u0000axis, can be captured by an orthogonal equilibrium during the decay of the\u0000stellar oblateness. However, the orbit will be eventually recaptured by the\u0000coplanar equilibrium, aligned or anti-aligned with the orientation of the outer\u0000orbit, resulting in either a prograde or retrograde inner-outer orbit\u0000configuration. Additionally, general relativity contributes to maintaining\u0000eccentricity stability within these dynamic scenarios. Through the proposed\u0000mechanism, we can provide a plausible explanation for the unique,\u0000near-perpendicular and likely retrograde orbit architecture observed in the HD\u00003167 system, enhancing our understanding of exoplanetary system dynamics.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204628","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}
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