Sanjay Baliwal, Rishikesh Sharma, Abhijit Chakraborty, Akanksha Khandelwal, K. J. Nikitha, Boris S. Safonov, Ivan A. Strakhov, Marco Montalto, Jason D. Eastman, David W. Latham, Allyson Bieryla, Neelam J. S. S. V. Prasad, Kapil K. Bharadwaj, Kevikumar A. Lad, Shubhendra N. Das, Ashirbad Nayak
We report the discovery and characterization of a transiting sub-Saturn exoplanet TOI-6651b using PARAS-2 spectroscopic observations. The host, TOI-6651 ($m_{V}approx 10.2$), is a sub-giant, metal-rich G-type star with $[{rm Fe/H}] = 0.225^{+0.044}_{-0.045}$, $T_{rm eff} = 5940pm110 mathrm{K}$, and $log{g} = 4.087^{+0.035}_{-0.032}$. Joint fitting of the radial velocities from PARAS-2 spectrograph and transit photometric data from Transiting Exoplanet Survey Satellite (TESS) reveals a planetary mass of $61.0^{+7.6}_{-7.9} M_oplus$ and radius of $5.09^{+0.27}_{-0.26} R_oplus$, in a $5.056973^{+0.000016}_{-0.000018}$ day orbit with an eccentricity of $0.091^{+0.096}_{-0.062}$. TOI-6651b has a bulk density of $2.52^{+0.52}_{-0.44} mathrm{g cm^{-3}}$, positioning it among the select few known dense sub-Saturns and making it notably the densest detected with TESS. TOI-6651b is consistent with the positive correlation between planet mass and the host star's metallicity. We find that a considerable portion $approx$ 87% of the planet's mass consists of dense materials such as rock and iron in the core, while the remaining mass comprises a low-density envelope of H/He. TOI-6651b lies at the edge of the Neptunian desert, which will be crucial for understanding the factors shaping the desert boundaries. The existence of TOI-6651b challenges conventional planet formation theories and could be a result of merging events or significant atmospheric mass loss through tidal heating, highlighting the complex interplay of dynamical processes and atmospheric evolution in the formation of massive dense sub-Saturns.
{"title":"Discovery and characterization of a dense sub-Saturn TOI-6651b","authors":"Sanjay Baliwal, Rishikesh Sharma, Abhijit Chakraborty, Akanksha Khandelwal, K. J. Nikitha, Boris S. Safonov, Ivan A. Strakhov, Marco Montalto, Jason D. Eastman, David W. Latham, Allyson Bieryla, Neelam J. S. S. V. Prasad, Kapil K. Bharadwaj, Kevikumar A. Lad, Shubhendra N. Das, Ashirbad Nayak","doi":"arxiv-2408.17179","DOIUrl":"https://doi.org/arxiv-2408.17179","url":null,"abstract":"We report the discovery and characterization of a transiting sub-Saturn\u0000exoplanet TOI-6651b using PARAS-2 spectroscopic observations. The host,\u0000TOI-6651 ($m_{V}approx 10.2$), is a sub-giant, metal-rich G-type star with\u0000$[{rm Fe/H}] = 0.225^{+0.044}_{-0.045}$, $T_{rm eff} = 5940pm110\u0000mathrm{K}$, and $log{g} = 4.087^{+0.035}_{-0.032}$. Joint fitting of the\u0000radial velocities from PARAS-2 spectrograph and transit photometric data from\u0000Transiting Exoplanet Survey Satellite (TESS) reveals a planetary mass of\u0000$61.0^{+7.6}_{-7.9} M_oplus$ and radius of $5.09^{+0.27}_{-0.26} R_oplus$,\u0000in a $5.056973^{+0.000016}_{-0.000018}$ day orbit with an eccentricity of\u0000$0.091^{+0.096}_{-0.062}$. TOI-6651b has a bulk density of\u0000$2.52^{+0.52}_{-0.44} mathrm{g cm^{-3}}$, positioning it among the select\u0000few known dense sub-Saturns and making it notably the densest detected with\u0000TESS. TOI-6651b is consistent with the positive correlation between planet mass\u0000and the host star's metallicity. We find that a considerable portion $approx$\u000087% of the planet's mass consists of dense materials such as rock and iron in\u0000the core, while the remaining mass comprises a low-density envelope of H/He.\u0000TOI-6651b lies at the edge of the Neptunian desert, which will be crucial for\u0000understanding the factors shaping the desert boundaries. The existence of\u0000TOI-6651b challenges conventional planet formation theories and could be a\u0000result of merging events or significant atmospheric mass loss through tidal\u0000heating, highlighting the complex interplay of dynamical processes and\u0000atmospheric evolution in the formation of massive dense sub-Saturns.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204631","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}
Damanveer S. Grewal, Nicole X. Nie, Bidong Zhang, Andre Izidoro, Paul D. Asimow
How and where the first generation of inner solar system planetesimals formed remains poorly understood. Potential formation regions are the silicate condensation line and water-snowline of the solar protoplanetary disk. Whether the chemical compositions of these planetesimals align with accretion at the silicate condensation line (water-free and reduced) or water-snowline (water-bearing and oxidized) is, however, unknown. Here we use Fe/Ni and Fe/Co ratios of magmatic iron meteorites to quantify the oxidation states of the earliest planetesimals associated with non-carbonaceous (NC) and carbonaceous (CC) reservoirs, representing the inner and outer solar system, respectively. Our results show that the earliest NC planetesimals contained substantial amounts of oxidized Fe in their mantles (3-19 wt% FeO). In turn, we argue that this required the accretion of water-bearing materials into these NC planetesimals. The presence of substantial quantities of moderately and highly volatile elements in their parent cores is also inconsistent with their accretion at the silicate condensation line and favors instead their formation at or beyond the water-snowline. Similar oxidation states in the early-formed parent bodies of NC iron meteorites and those of NC achondrites and chondrites with diverse accretion ages suggests that the formation of oxidized planetesimals from water-bearing materials was widespread in the early history of the inner solar system.
{"title":"Accretion of the earliest inner solar system planetesimals beyond the water-snowline","authors":"Damanveer S. Grewal, Nicole X. Nie, Bidong Zhang, Andre Izidoro, Paul D. Asimow","doi":"arxiv-2408.17032","DOIUrl":"https://doi.org/arxiv-2408.17032","url":null,"abstract":"How and where the first generation of inner solar system planetesimals formed\u0000remains poorly understood. Potential formation regions are the silicate\u0000condensation line and water-snowline of the solar protoplanetary disk. Whether\u0000the chemical compositions of these planetesimals align with accretion at the\u0000silicate condensation line (water-free and reduced) or water-snowline\u0000(water-bearing and oxidized) is, however, unknown. Here we use Fe/Ni and Fe/Co\u0000ratios of magmatic iron meteorites to quantify the oxidation states of the\u0000earliest planetesimals associated with non-carbonaceous (NC) and carbonaceous\u0000(CC) reservoirs, representing the inner and outer solar system, respectively.\u0000Our results show that the earliest NC planetesimals contained substantial\u0000amounts of oxidized Fe in their mantles (3-19 wt% FeO). In turn, we argue that\u0000this required the accretion of water-bearing materials into these NC\u0000planetesimals. The presence of substantial quantities of moderately and highly\u0000volatile elements in their parent cores is also inconsistent with their\u0000accretion at the silicate condensation line and favors instead their formation\u0000at or beyond the water-snowline. Similar oxidation states in the early-formed\u0000parent bodies of NC iron meteorites and those of NC achondrites and chondrites\u0000with diverse accretion ages suggests that the formation of oxidized\u0000planetesimals from water-bearing materials was widespread in the early history\u0000of the inner solar system.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226054","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}
K. L. Chubb, D. Samra, Ch. Helling, L. Carone, D. M. Stam
We simulate the geometric albedo spectra of hot Jupiter exoplanets HD 209458 b and WASP-43 b, based on global climate model (GCMs) post-processed with kinetic cloud models. We predict WASP-43 b to be cloudy throughout its dayside, while HD 209458 b has a clear upper atmosphere around the hot sub-solar point, largely due to the inclusion of strong optical absorbers TiO and VO in the GCM for the latter causes a temperature inversion. In both cases our models find low geometric albedos - 0.026 for WASP-43b and 0.028 for HD 209458 b when averaged over the CHEOPS bandpass of 0.35 - 1.1 microns - indicating dark daysides, similar to the low albedos measured by observations. We demonstrate the strong impact of clouds that contain Fe-bearing species on the modelled geometric albedos; without Fe-bearing species forming in the clouds, the albedos of both planets would be much higher (0.518 for WASP-43 b, 1.37 for HD 209458 b). We conclude that a cloudy upper or mid-to-lower atmosphere that contains strongly absorbing Fe-bearing aerosol species, is an alternative to a cloud-free atmosphere in explaining the low dayside albedos of hot Jupiter atmospheres such as HD 209458 b and WASP-43 b.
我们模拟了热木星系外行星HD 209458b和WASP-43 b的几何反照率光谱，其依据是经动能云模型后处理的全球气候模型（GCM）。我们预测 WASP-43 b 的整个日侧都是多云的，而 HD 209458 b 在热亚太阳点附近的上层大气是清晰的，这主要是由于在全球气候模型中加入了强光学吸收体 TiO 和 VO，后者会导致温度反转。在这两种情况下，我们的模型都发现了较低的几何反照率--WASP-43b 为 0.026，HD 209458 b 为 0.028（在 0.35 - 1.1 微米的 CHEOPS 波段范围内平均）--这表明天色较暗，与观测所测得的低反照率相似。我们证明了含有含铁物质的云层对模拟几何反照率的强烈影响；如果云层中没有含铁物质，两颗行星的反照率都会高得多（WASP-43 b 为 0.518，HD209458 b 为 1.37）。我们的结论是，在解释 HD 209458 b 和 WASP-43 b 等热木星大气层的低日侧反照率时，含有强吸收性含铁气溶胶物种的多云上层或中下层大气是无云大气的替代选择。
{"title":"The dark days are overcast: Iron-bearing clouds on HD 209458 b and WASP-43 b can explain low dayside albedos","authors":"K. L. Chubb, D. Samra, Ch. Helling, L. Carone, D. M. Stam","doi":"arxiv-2409.00249","DOIUrl":"https://doi.org/arxiv-2409.00249","url":null,"abstract":"We simulate the geometric albedo spectra of hot Jupiter exoplanets HD 209458\u0000b and WASP-43 b, based on global climate model (GCMs) post-processed with\u0000kinetic cloud models. We predict WASP-43 b to be cloudy throughout its dayside,\u0000while HD 209458 b has a clear upper atmosphere around the hot sub-solar point,\u0000largely due to the inclusion of strong optical absorbers TiO and VO in the GCM\u0000for the latter causes a temperature inversion. In both cases our models find\u0000low geometric albedos - 0.026 for WASP-43b and 0.028 for HD 209458 b when\u0000averaged over the CHEOPS bandpass of 0.35 - 1.1 microns - indicating dark\u0000daysides, similar to the low albedos measured by observations. We demonstrate\u0000the strong impact of clouds that contain Fe-bearing species on the modelled\u0000geometric albedos; without Fe-bearing species forming in the clouds, the\u0000albedos of both planets would be much higher (0.518 for WASP-43 b, 1.37 for HD\u0000209458 b). We conclude that a cloudy upper or mid-to-lower atmosphere that\u0000contains strongly absorbing Fe-bearing aerosol species, is an alternative to a\u0000cloud-free atmosphere in explaining the low dayside albedos of hot Jupiter\u0000atmospheres such as HD 209458 b and WASP-43 b.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"403 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204629","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}
Most exoplanets with a few Earth radii are more inflated than bare-rock planets with the same mass, indicating a substantial volatile amount. Neither the origin of the volatiles nor the planet's bulk composition can be constrained from the mass-radius relation alone, and the spectral characterization of their atmospheres is needed to solve this degeneracy. Previous studies showed that chemical interaction between accreted volatile and possible molten rocky surface (i.e., magma ocean) can greatly affects the atmospheric composition. However, a variety in the atmospheric compositions of such planets with different properties remains elusive. In this work, we examine the dependence of atmospheric H, O, and C on planetary parameters (atmospheric thickness, planetary mass, equilibrium temperature, and magma properties such as redox state) assuming nebula gas accretion on an Earth-like core, using an atmosphere-magma chemical equilibrium model. Consistent with previous work, we show that atmospheric $rm H_{2}O$ fraction on a fully molten rocky interior with an Earth-like redox state is on the order of $10^{-2}$-$10^{-1}$ regardless of other planetary parameters. Despite the solubility difference between H- and C-bearing species, C/H increases only a few times above the nebula value except for atmospheric pressure $lesssim$1000 bar and $rm H_{2}O$ fraction $gtrsim$10%. This results in a negative O/H-C/O trend and depleted C/O below one-tenth of the nebula gas value under an oxidized atmosphere, which could provide a piece of evidence of rocky interior and endogenic water. We also highlight the importance of constraints on the high-pressure material properties for interpreting the magma-atmospheric interaction of inflated planets.
{"title":"Role of magma oceans in controlling carbon and oxygen of sub-Neptune atmospheres","authors":"Chanoul Seo, Yuichi Ito, Yuka Fujii","doi":"arxiv-2408.17056","DOIUrl":"https://doi.org/arxiv-2408.17056","url":null,"abstract":"Most exoplanets with a few Earth radii are more inflated than bare-rock\u0000planets with the same mass, indicating a substantial volatile amount. Neither\u0000the origin of the volatiles nor the planet's bulk composition can be\u0000constrained from the mass-radius relation alone, and the spectral\u0000characterization of their atmospheres is needed to solve this degeneracy.\u0000Previous studies showed that chemical interaction between accreted volatile and\u0000possible molten rocky surface (i.e., magma ocean) can greatly affects the\u0000atmospheric composition. However, a variety in the atmospheric compositions of\u0000such planets with different properties remains elusive. In this work, we\u0000examine the dependence of atmospheric H, O, and C on planetary parameters\u0000(atmospheric thickness, planetary mass, equilibrium temperature, and magma\u0000properties such as redox state) assuming nebula gas accretion on an Earth-like\u0000core, using an atmosphere-magma chemical equilibrium model. Consistent with\u0000previous work, we show that atmospheric $rm H_{2}O$ fraction on a fully molten\u0000rocky interior with an Earth-like redox state is on the order of\u0000$10^{-2}$-$10^{-1}$ regardless of other planetary parameters. Despite the\u0000solubility difference between H- and C-bearing species, C/H increases only a\u0000few times above the nebula value except for atmospheric pressure $lesssim$1000\u0000bar and $rm H_{2}O$ fraction $gtrsim$10%. This results in a negative O/H-C/O\u0000trend and depleted C/O below one-tenth of the nebula gas value under an\u0000oxidized atmosphere, which could provide a piece of evidence of rocky interior\u0000and endogenic water. We also highlight the importance of constraints on the\u0000high-pressure material properties for interpreting the magma-atmospheric\u0000interaction of inflated planets.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Atmospheres above lava-ocean planets (LOPs) hold clues as to the properties of their interiors, owing to the expectation that the two reservoirs are in chemical equilibrium. Here we consider `mineral' atmospheres produced in equilibrium with silicate liquids. We treat oxygen fugacity ($f$O$_2$) as an independent variable, together with temperature ($T$) and composition ($X$), to compute equilibrium partial pressures ($p$) of stable gas species at the liquid-gas interface. Above this boundary, the atmospheric speciation and the pressure-temperature structure are computed self-consistently to yield emission spectra. We explore a wide array of plausible compositions, oxygen fugacities (between 6 log$_{10}$ units below- and above the iron-w"ustite buffer, IW) and irradiation temperatures (2000, 2500, 3000 and 3500 K) relevant to LOPs. We find that SiO(g), Fe(g) and Mg(g) are the major species below $sim$IW, ceding to O$_2$(g) and O(g) in more oxidised atmospheres. The transition between the two regimes demarcates a minimum in total pressure ($P$). Because $p$ scales linearly with $X$, emission spectra are only modest functions of composition. By contrast, $f$O$_2$ can vary over orders of magnitude, thus causing commensurate changes in $p$. Reducing atmospheres show intense SiO emission, creating a temperature inversion in the upper atmosphere. Conversely, oxidised atmospheres have lower $p$SiO and lack thermal inversions, with resulting emission spectra that mimic that of a black body. Consequently, the intensity of SiO emission relative to the background, generated by MgO(g), can be used to quantify the $f$O$_2$ of the atmosphere. Depending on the emission spectroscopy metric of the target, deriving the $f$O$_2$ of known nearby LOPs is possible with a few secondary occultations observed by JWST.
{"title":"Impact of oxygen fugacity on atmospheric structure and emission spectra of ultra hot rocky exoplanets","authors":"Fabian L. Seidler, Paolo A. Sossi, Simon L. Grimm","doi":"arxiv-2408.16548","DOIUrl":"https://doi.org/arxiv-2408.16548","url":null,"abstract":"Atmospheres above lava-ocean planets (LOPs) hold clues as to the properties\u0000of their interiors, owing to the expectation that the two reservoirs are in\u0000chemical equilibrium. Here we consider `mineral' atmospheres produced in\u0000equilibrium with silicate liquids. We treat oxygen fugacity ($f$O$_2$) as an\u0000independent variable, together with temperature ($T$) and composition ($X$), to\u0000compute equilibrium partial pressures ($p$) of stable gas species at the\u0000liquid-gas interface. Above this boundary, the atmospheric speciation and the\u0000pressure-temperature structure are computed self-consistently to yield emission\u0000spectra. We explore a wide array of plausible compositions, oxygen fugacities\u0000(between 6 log$_{10}$ units below- and above the iron-w\"ustite buffer, IW) and\u0000irradiation temperatures (2000, 2500, 3000 and 3500 K) relevant to LOPs. We\u0000find that SiO(g), Fe(g) and Mg(g) are the major species below $sim$IW, ceding\u0000to O$_2$(g) and O(g) in more oxidised atmospheres. The transition between the\u0000two regimes demarcates a minimum in total pressure ($P$). Because $p$ scales\u0000linearly with $X$, emission spectra are only modest functions of composition.\u0000By contrast, $f$O$_2$ can vary over orders of magnitude, thus causing\u0000commensurate changes in $p$. Reducing atmospheres show intense SiO emission,\u0000creating a temperature inversion in the upper atmosphere. Conversely, oxidised\u0000atmospheres have lower $p$SiO and lack thermal inversions, with resulting\u0000emission spectra that mimic that of a black body. Consequently, the intensity\u0000of SiO emission relative to the background, generated by MgO(g), can be used to\u0000quantify the $f$O$_2$ of the atmosphere. Depending on the emission spectroscopy\u0000metric of the target, deriving the $f$O$_2$ of known nearby LOPs is possible\u0000with a few secondary occultations observed by JWST.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"50 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204635","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}
Mathilde Mâlin, Anthony Boccaletti, Clément Perrot, Pierre Baudoz, Daniel Rouan, Pierre-Olivier Lagage, Rens Waters, Manuel Güdel, Thomas Henning, Bart Vandenbussche, Olivier Absil, David Barrado, Jeroen Bouwman, Christophe Cossou, Leen Decin, Adrian M. Glauser, John Pye, Goran Olofsson, Alistair Glasse, Fred Lahuis, Polychronis Patapis, Pierre Royer, Silvia Scheithauer, Niall Whiteford, Eugene Serabyn, Elodie Choquet, Luis Colina, Göran Ostlin, Ewine F. van Dishoeck, Tom P. Ray, Gillian Wright
Mid-infrared imaging of exoplanets and disks is now possible with the coronagraphs of the MIRI on the JWST. This wavelength range unveils new features of young directly imaged systems and allows us to obtain new constraints for characterizing the atmosphere of young giant exoplanets and associated disks. These observations aim to characterize the atmosphere of the planet HD 95086 b by adding mid-infrared information so that the various hypotheses about its atmospheric parameters values can be unraveled. Improved images of circumstellar disks are provided. We present the MIRI coronagraphic imaging of the system HD 95086 obtained with the F1065C, F1140, and F2300C filters at central wavelengths of 10.575, 11.3, and 23 microns, respectively. We explored the method for subtracting the stellar diffraction pattern in the particular case when bright dust emitting at short separation is present. Furthermore, we compared different methods for extracting the photometry of the planet. Using the atmospheric models Exo-REM and ATMO, we measured the atmospheric parameters of HD 95086 b. The planet HD 95086 b and the contribution from the inner disk are detected at the two shortest MIRI wavelengths F1065C and F1140C. The outer colder belt is imaged at 23 microns. The mid-infrared photometry provides better constraints on the atmospheric parameters. We evaluate a temperature of 850-1020 K, consistent with one previous hypothesis that only used NIR data. The radius measurement of 1.0-1.13 RJup is better aligned with evolutionary models, but still smaller than predicted. These observations allow us to refute the hypothesis of a warm circumplanetary disk. HD 95086 is one of the first exoplanetary systems to be revealed at mid-infrared wavelengths. This highlights the interests and challenges of observations at these wavelengths.
{"title":"Unveiling the HD 95086 system at mid-infrared wavelengths with JWST/MIRI","authors":"Mathilde Mâlin, Anthony Boccaletti, Clément Perrot, Pierre Baudoz, Daniel Rouan, Pierre-Olivier Lagage, Rens Waters, Manuel Güdel, Thomas Henning, Bart Vandenbussche, Olivier Absil, David Barrado, Jeroen Bouwman, Christophe Cossou, Leen Decin, Adrian M. Glauser, John Pye, Goran Olofsson, Alistair Glasse, Fred Lahuis, Polychronis Patapis, Pierre Royer, Silvia Scheithauer, Niall Whiteford, Eugene Serabyn, Elodie Choquet, Luis Colina, Göran Ostlin, Ewine F. van Dishoeck, Tom P. Ray, Gillian Wright","doi":"arxiv-2408.16843","DOIUrl":"https://doi.org/arxiv-2408.16843","url":null,"abstract":"Mid-infrared imaging of exoplanets and disks is now possible with the\u0000coronagraphs of the MIRI on the JWST. This wavelength range unveils new\u0000features of young directly imaged systems and allows us to obtain new\u0000constraints for characterizing the atmosphere of young giant exoplanets and\u0000associated disks. These observations aim to characterize the atmosphere of the\u0000planet HD 95086 b by adding mid-infrared information so that the various\u0000hypotheses about its atmospheric parameters values can be unraveled. Improved\u0000images of circumstellar disks are provided. We present the MIRI coronagraphic\u0000imaging of the system HD 95086 obtained with the F1065C, F1140, and F2300C\u0000filters at central wavelengths of 10.575, 11.3, and 23 microns, respectively.\u0000We explored the method for subtracting the stellar diffraction pattern in the\u0000particular case when bright dust emitting at short separation is present.\u0000Furthermore, we compared different methods for extracting the photometry of the\u0000planet. Using the atmospheric models Exo-REM and ATMO, we measured the\u0000atmospheric parameters of HD 95086 b. The planet HD 95086 b and the\u0000contribution from the inner disk are detected at the two shortest MIRI\u0000wavelengths F1065C and F1140C. The outer colder belt is imaged at 23 microns.\u0000The mid-infrared photometry provides better constraints on the atmospheric\u0000parameters. We evaluate a temperature of 850-1020 K, consistent with one\u0000previous hypothesis that only used NIR data. The radius measurement of 1.0-1.13\u0000RJup is better aligned with evolutionary models, but still smaller than\u0000predicted. These observations allow us to refute the hypothesis of a warm\u0000circumplanetary disk. HD 95086 is one of the first exoplanetary systems to be\u0000revealed at mid-infrared wavelengths. This highlights the interests and\u0000challenges of observations at these wavelengths.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204634","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}
Discoveries of close-in young puffy (R$_p gtrsim$ 6 R$_oplus$) planets raise the question of whether they are bona fide hot Jupiters or puffed-up Neptunes, potentially placing constraints on the formation location and timescale of hot Jupiters. Obtaining mass measurements for these planets is challenging due to stellar activity and noisy spectra. Therefore, we aim to provide independent theoretical constraints on the masses of these young planets based on their radii, incident fluxes, and ages, benchmarking to the planets of age $<$1 Gyr detected by Kepler, K2 and TESS. Through a combination of interior structure models, considerations of photoevaporative mass loss, and empirical mass-metallicity trends, we present the range of possible masses for 24 planets of age $sim$10-900 Myr and radii $sim$6-16 R$_oplus$. We generally find that our mass estimates are in agreement with the measured masses and upper limits where applicable. There exist some outliers including super-puffs Kepler-51 b, c and V1298 Tau d, b, e, for which we outline their likely formation conditions. Our analyses demonstrate that most of the youngest planets ($lesssim$ 100 Myr) tend to be puffed-up, Neptune-mass planets, while the true hot Jupiters are typically found around stars aged at least a few hundred Myr, suggesting the dominant origin of hot Jupiters to be late-stage high eccentricity migration.
{"title":"Separating Super-Puffs vs. Hot Jupiters Among Young Puffy Planets","authors":"Amalia Karalis, Eve J. Lee, Daniel P. Thorngren","doi":"arxiv-2408.16793","DOIUrl":"https://doi.org/arxiv-2408.16793","url":null,"abstract":"Discoveries of close-in young puffy (R$_p gtrsim$ 6 R$_oplus$) planets\u0000raise the question of whether they are bona fide hot Jupiters or puffed-up\u0000Neptunes, potentially placing constraints on the formation location and\u0000timescale of hot Jupiters. Obtaining mass measurements for these planets is\u0000challenging due to stellar activity and noisy spectra. Therefore, we aim to\u0000provide independent theoretical constraints on the masses of these young\u0000planets based on their radii, incident fluxes, and ages, benchmarking to the\u0000planets of age $<$1 Gyr detected by Kepler, K2 and TESS. Through a combination\u0000of interior structure models, considerations of photoevaporative mass loss, and\u0000empirical mass-metallicity trends, we present the range of possible masses for\u000024 planets of age $sim$10-900 Myr and radii $sim$6-16 R$_oplus$. We\u0000generally find that our mass estimates are in agreement with the measured\u0000masses and upper limits where applicable. There exist some outliers including\u0000super-puffs Kepler-51 b, c and V1298 Tau d, b, e, for which we outline their\u0000likely formation conditions. Our analyses demonstrate that most of the youngest\u0000planets ($lesssim$ 100 Myr) tend to be puffed-up, Neptune-mass planets, while\u0000the true hot Jupiters are typically found around stars aged at least a few\u0000hundred Myr, suggesting the dominant origin of hot Jupiters to be late-stage\u0000high eccentricity migration.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204633","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}
Amélie Gressier, Néstor Espinoza, Natalie H. Allen, David K. Sing, Agnibha Banerjee, Joanna K. Barstow, Jeff A. Valenti, Nikole K. Lewis, Stephan M. Birkmann, Ryan C. Challener, Elena Manjavacas, Catarina Alves de Oliveira, Nicolas Crouzet, Tracy. L Beck
Detecting atmospheres around planets with a radius below 1.6 R$_{oplus}$, commonly referred to as rocky planets (Rogers_2015, Rogers_2021), has proven to be challenging. However, rocky planets orbiting M-dwarfs are ideal candidates due to their favorable planet-to-star radius ratio. Here, we present one transit observation of the Super-Earth L98-59d (1.58 R$_{oplus}$, 2.31 M$_{oplus}$), at the limit of rocky/gas-rich, using the JWST NIRSpec G395H mode covering the 2.8 to 5.1 microns wavelength range. The extracted transit spectrum from a single transit observation deviates from a flat line by 2.6 to 5.6$sigma$, depending on the data reduction and retrieval setup. The hints of an atmospheric detection are driven by a large absorption feature between 3.3 to 4.8 microns. A stellar contamination retrieval analysis rejected the source of this feature as being due to stellar inhomogeneities, making the best fit an atmospheric model including sulfur-bearing species, suggesting that the atmosphere of L98-59d may not be at equilibrium. This result will need to be confirmed by the analysis of the second NIRSpec G395H visit in addition to the NIRISS SOSS transit observation.
{"title":"Hints of a sulfur-rich atmosphere around the 1.6 R$_{oplus}$ Super-Earth L98-59 d from JWST NIRSpec G395H transmission spectroscopy","authors":"Amélie Gressier, Néstor Espinoza, Natalie H. Allen, David K. Sing, Agnibha Banerjee, Joanna K. Barstow, Jeff A. Valenti, Nikole K. Lewis, Stephan M. Birkmann, Ryan C. Challener, Elena Manjavacas, Catarina Alves de Oliveira, Nicolas Crouzet, Tracy. L Beck","doi":"arxiv-2408.15855","DOIUrl":"https://doi.org/arxiv-2408.15855","url":null,"abstract":"Detecting atmospheres around planets with a radius below 1.6 R$_{oplus}$,\u0000commonly referred to as rocky planets (Rogers_2015, Rogers_2021), has proven to\u0000be challenging. However, rocky planets orbiting M-dwarfs are ideal candidates\u0000due to their favorable planet-to-star radius ratio. Here, we present one\u0000transit observation of the Super-Earth L98-59d (1.58 R$_{oplus}$, 2.31\u0000M$_{oplus}$), at the limit of rocky/gas-rich, using the JWST NIRSpec G395H\u0000mode covering the 2.8 to 5.1 microns wavelength range. The extracted transit\u0000spectrum from a single transit observation deviates from a flat line by 2.6 to\u00005.6$sigma$, depending on the data reduction and retrieval setup. The hints of\u0000an atmospheric detection are driven by a large absorption feature between 3.3\u0000to 4.8 microns. A stellar contamination retrieval analysis rejected the source\u0000of this feature as being due to stellar inhomogeneities, making the best fit an\u0000atmospheric model including sulfur-bearing species, suggesting that the\u0000atmosphere of L98-59d may not be at equilibrium. This result will need to be\u0000confirmed by the analysis of the second NIRSpec G395H visit in addition to the\u0000NIRISS SOSS transit observation.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"51 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204456","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}
Ocean salinity is known to dramatically affect the climates of Earth-like planets orbiting Sun-like stars, with high salinity leading to less ice and higher surface temperature. However, how ocean composition impacts climate under different conditions, such as around different types of stars or at different positions within the habitable zone, has not been investigated. We used ROCKE-3D, an ocean-atmosphere general circulation model, to simulate how planetary climate responds to ocean salinities for planets with G-star vs. M-dwarf hosts at several stellar fluxes. We find that increasing ocean salinity from 20 to 100 g/kg in our model results in non-linear ice reduction and warming on G-star planets, sometimes causing abrupt transitions to different climate states. Conversely, sea ice on M-dwarf planets responds more gradually and linearly to increasing salinity. Moreover, reductions in sea ice on M-dwarf planets are not accompanied by significant surface warming as on G-star planets. High salinity can modestly bolster the resilience of M-dwarf planets against snowball glaciation and allow these planets to retain surface liquid water further from their host star, but the effects are muted compared to G-star planets that experience snowball bifurcation and climate hysteresis due to the ice-albedo feedback.
众所周知，海洋盐度会极大地影响围绕类太阳恒星运行的类地行星的气候，高盐度会导致较少的冰和较高的表面温度。然而，海洋成分如何影响不同条件下的气候，如不同类型恒星周围或宜居带内的不同位置，还没有进行过研究。我们利用海洋-大气环流模型 ROCKE-3D 模拟了在几种恒星通量下 G 星与 M 矮星宿主行星的海洋盐度对行星气候的影响。我们发现，在我们的模型中，海洋盐度从 20 克/千克增加到 100 克/千克会导致 G 星行星上的冰非线性减少和变暖，有时会导致突然过渡到不同的气候状态。与此相反，M-矮行星上的海冰对盐度增加的反应更为渐进和线性。此外，M-矮行星上海冰的减少并不像G-星行星那样伴随着显著的表面升温。高盐度可以适度地增强M-矮行星抵御雪球冰川作用的能力，并使这些行星能够在离其主恒星更远的地方保留表面液态水，但与经历雪球分叉和气候滞后的G-星行星相比，这种影响是微弱的，因为G-星行星会经历冰-碱度反馈。
{"title":"Climatic Effects of Ocean Salinity on M Dwarf Exoplanets","authors":"Kyle Batra, Stephanie L. Olson","doi":"arxiv-2408.04754","DOIUrl":"https://doi.org/arxiv-2408.04754","url":null,"abstract":"Ocean salinity is known to dramatically affect the climates of Earth-like\u0000planets orbiting Sun-like stars, with high salinity leading to less ice and\u0000higher surface temperature. However, how ocean composition impacts climate\u0000under different conditions, such as around different types of stars or at\u0000different positions within the habitable zone, has not been investigated. We\u0000used ROCKE-3D, an ocean-atmosphere general circulation model, to simulate how\u0000planetary climate responds to ocean salinities for planets with G-star vs.\u0000M-dwarf hosts at several stellar fluxes. We find that increasing ocean salinity\u0000from 20 to 100 g/kg in our model results in non-linear ice reduction and\u0000warming on G-star planets, sometimes causing abrupt transitions to different\u0000climate states. Conversely, sea ice on M-dwarf planets responds more gradually\u0000and linearly to increasing salinity. Moreover, reductions in sea ice on M-dwarf\u0000planets are not accompanied by significant surface warming as on G-star\u0000planets. High salinity can modestly bolster the resilience of M-dwarf planets\u0000against snowball glaciation and allow these planets to retain surface liquid\u0000water further from their host star, but the effects are muted compared to\u0000G-star planets that experience snowball bifurcation and climate hysteresis due\u0000to the ice-albedo feedback.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"85 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141931831","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}
Althea V. Moorhead, William J. Cooke, Peter G. Brown, Margaret D. Campbell-Brown
Although the risk posed to spacecraft due to meteoroid impacts is dominated by sporadic meteoroids, meteor showers can raise this risk for short periods of time. NASA's Meteoroid Environment Office issues meteor shower forecasts that describe these periods of elevated risk, primarily for the purpose of helping plan extravehicular activities. These forecasts are constructed using a list of meteor shower parameters that has evolved over time to include newly discovered showers and incorporate improved measurements of their characteristics. However, at this point in time, more than a thousand meteor showers have been reported by researchers, many of which are extremely minor, are unconfirmed, or lack measurements of critical parameters. Thus, a comprehensive approach is no longer feasible. In this report we present a quantitative criterion for a potentially hazardous meteor shower and apply this criterion to the list of established meteor showers in order to determine which showers should be included in our annual forecasts.
{"title":"The threshold at which a meteor shower becomes hazardous to spacecraft","authors":"Althea V. Moorhead, William J. Cooke, Peter G. Brown, Margaret D. Campbell-Brown","doi":"arxiv-2408.04612","DOIUrl":"https://doi.org/arxiv-2408.04612","url":null,"abstract":"Although the risk posed to spacecraft due to meteoroid impacts is dominated\u0000by sporadic meteoroids, meteor showers can raise this risk for short periods of\u0000time. NASA's Meteoroid Environment Office issues meteor shower forecasts that\u0000describe these periods of elevated risk, primarily for the purpose of helping\u0000plan extravehicular activities. These forecasts are constructed using a list of\u0000meteor shower parameters that has evolved over time to include newly discovered\u0000showers and incorporate improved measurements of their characteristics.\u0000However, at this point in time, more than a thousand meteor showers have been\u0000reported by researchers, many of which are extremely minor, are unconfirmed, or\u0000lack measurements of critical parameters. Thus, a comprehensive approach is no\u0000longer feasible. In this report we present a quantitative criterion for a\u0000potentially hazardous meteor shower and apply this criterion to the list of\u0000established meteor showers in order to determine which showers should be\u0000included in our annual forecasts.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141968666","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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