arXiv - PHYS - Earth and Planetary Astrophysics最新文献

{"title":"The secondary classification of unequilibrated chondrites","authors":"Emmanuel Jacquet, Béatrice Doisneau","doi":"arxiv-2409.07838","DOIUrl":"https://doi.org/arxiv-2409.07838","url":null,"abstract":"The multiplication of decimal petrologic schemes for different or the same\u0000chondrite groups evinces a lack of unified guiding principle in the secondary\u0000classification of type 1-3 chondrites. We show that the current OC, R and CO\u0000classifications can be a posteriori unified, with only minor reclassifications,\u0000if the decimal part of the subtype is defined as the ratio $m=Fa_I/Fa_{II}$ of\u0000the mean fayalite contents of type I and type II chondrules rounded to the\u0000nearest tenth (with adaptations from Cr systematics for the lowest subtypes).\u0000This parameter is more efficiently evaluable than the oft-used relative\u0000standard deviations of fayalite contents and defines a general metamorphic\u0000scale from M0.0 to M1 (where the suffixed number is the rounded $m$). Type 3\u0000chondrites thus span the range M0.0-M0.9 and M1 designates type 4.\u0000Corresponding applications are then proposed for other chondrite groups. Known\u0000type 1 and 2 chondrites are at M0.0 (i.e. the metamorphic grade of type 3.0\u0000chondrites). Independently, we define an aqueous alteration scale from A0.0 to\u0000A1.0, where the suffixed number is the (rounded) phyllosilicate fraction (PSF).\u0000For CM and CR chondrites, the subtypes can be characterized in terms of the\u0000thin-section-based criteria of previous schemes which are thus incorporated in\u0000the present framework. The rounding of the PSF to the (in principle) nearest\u0000tenth makes the proposed taxonomy somewhat coarser than those schemes, but\u0000hereby more robust and more likely to be generalized in future meteorite\u0000declarations. We propose the corresponding petrologic subtype to be 3-PSF,\u0000rounded to the nearest tenth (so that type 1 would correspond to subtypes 2.0\u0000and 2.1). At the level of precision chosen, nonzero alteration and metamorphic\u0000degrees remain mutually exclusive, so that a single petrologic subtype\u0000$approx$ 3+$m$-PSF indeed remains a good descriptor of secondary processes.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204554","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":"Constraining atmospheric composition from the outflow: helium observations reveal the fundamental properties of two planets straddling the radius gap","authors":"Michael Zhang, Jacob L. Bean, David Wilson, Girish Duvvuri, Christian Schneider, Heather A. Knutson, Fei Dai, Karen A. Collins, Cristilyn N. Watkins, Richard P. Schwarz, Khalid Barkaoui, Avi Shporer, Keith Horne, Ramotholo Sefako, Felipe Murgas, Enric Palle","doi":"arxiv-2409.08318","DOIUrl":"https://doi.org/arxiv-2409.08318","url":null,"abstract":"TOI-836 is a $sim2-3$ Gyr K dwarf with an inner super Earth\u0000($R=1.7,R_oplus$, $P=3.8,d$) and an outer mini Neptune ($R=2.6,R_oplus$,\u0000$P=8.6,d$). Recent JWST/NIRSpec 2.8--5.2 $mu$m observations have revealed\u0000flat transmission spectra for both planets. We present Keck/NIRSPEC\u0000observations of escaping helium from this system. While planet b shows no\u0000absorption in the 1083 nm line to deep limits ($<0.2$%), 836c shows strong\u0000(0.7%) absorption in both visits. These results demonstrate that the inner\u0000super-Earth has lost its primordial atmosphere while the outer mini-Neptune has\u0000not. Self-consistent 1D radiative-hydrodynamic models of c using pyTPCI, an\u0000updated version of The PLUTO-CLOUDY Interface, reveal that the helium signal is\u0000highly sensitive to metallicity: its equivalent width collapses by a factor of\u000013 as metallicity increases from 10x to 100x solar, and by a further factor of\u000012 as it increases to 200x solar. The observed equivalent width is 88% of the\u0000model prediction for 100x metallicity, suggesting that c may have an\u0000atmospheric metallicity close to 100x solar. This is similar to K2-18b and\u0000TOI-270d, the first two mini-Neptunes with detected absorption features in JWST\u0000transmission spectra. We highlight the helium triplet as a potentially powerful\u0000probe of atmospheric composition, with complementary strengths and weaknesses\u0000to atmospheric retrievals. The main strength is its extreme sensitivity to\u0000metallicity in the scientifically significant range of 10--200x solar, and the\u0000main weakness is the enormous model uncertainties in outflow suppression and\u0000confinement mechanisms, such as magnetic fields and stellar winds.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263887","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":"Coma composition and profiles of comet 12P/Pons-Brooks using long-slit spectroscopy","authors":"Lea Ferellec, Cyrielle Opitom, Abbie Donaldson, Johan P. U. Fynbo, Rosita Kokotanekova, Michael S. P. Kelley, Tim Lister","doi":"arxiv-2409.08133","DOIUrl":"https://doi.org/arxiv-2409.08133","url":null,"abstract":"Comet 12P/Pons-Brook exhibited multiple large and minor outbursts in 2023 on\u0000its way to its 2024 perihelion, as it has done during its previous apparitions.\u0000We obtained long-slit optical spectra of the comet in 2023 August and 2023\u0000November with the INT-IDS, and in 2023 December with NOT-ALFOSC. Using a\u0000standard Haser model in a 10000km-radius aperture and commonly used empirical\u0000parent and daughter scale-lengths, our calculated abundance ratios show a\u0000constant \"typical\" composition throughout the period with a C$_2$/CN ratio of\u0000about 90 per cent. Molecular density profiles of different species along the\u0000slit show asymmetries between opposite sides of the coma and that C$_2$ seems\u0000to behave differently than CN and C$_3$. Comparing the coma profiles to a\u0000standard Haser model shows that this model cannot accurately reproduce the\u0000shape of the coma, and therefore that the calculated production rates cannot be\u0000deemed as accurate. We show that an outburst Haser model is a {slightly} better\u0000match to the C$_3$ and CN profile shapes, but the model still does not explain\u0000the shape of the C$_2$ profiles and requires equal parent and daughter\u0000scale-lengths. Our results suggest that the coma morphology could be better\u0000explained by extended sources, and that the nature of 12P's activity introduces\u0000bias in the determination of its composition.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204551","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":"Hot Jupiters are asynchronous rotators","authors":"Marek Wazny, Kristen Menou","doi":"arxiv-2409.07651","DOIUrl":"https://doi.org/arxiv-2409.07651","url":null,"abstract":"Hot Jupiters are typically assumed to be synchronously rotating, from tidal\u0000locking. Their thermally-driven atmospheric winds experience Lorentz drag on\u0000the planetary magnetic field anchored at depth. We find that the magnetic\u0000torque does not integrate to zero over the entire atmosphere. The resulting\u0000angular momentum feedback on the bulk interior can thus drive the planet away\u0000from synchronous rotation. Using a toy tidal-ohmic model and atmospheric GCM\u0000outputs for HD189733b, HD209458b and Kepler7b, we establish that\u0000off-synchronous rotation can be substantial at tidal-ohmic equilibrium for\u0000sufficiently hot and/or magnetized hot Jupiters. Potential consequences of\u0000asynchronous rotation for hot Jupiter phenomenology motivate follow-up work on\u0000the tidal-ohmic scenario with approaches that go beyond our toy model.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204557","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":"Nightside Clouds on Tidally-locked Terrestrial Planets Mimic Atmosphere-Free Scenarios","authors":"Diana Powell, Robin Wordsworth, Karin Öberg","doi":"arxiv-2409.07542","DOIUrl":"https://doi.org/arxiv-2409.07542","url":null,"abstract":"We investigate the impact of nightside cloud formation on the observable\u0000night-day contrast of tidally-locked terrestrial planet atmospheres. We\u0000demonstrate that, in the case where the planetary dayside is only 10s of Kelvin\u0000hotter than the planetary nightside, the presence of optically thick nightside\u0000clouds can lead to observations that mimic a planet without an atmosphere,\u0000despite the planet actually hosting a significant (10 bar) atmosphere. The\u0000scenario presented in this work requires a level of intrinsic atmospheric\u0000day/night temperature contrast such that the nightside can form clouds while\u0000the dayside is too hot for cloud formation to occur. This scenario is most\u0000likely for hotter terrestrials and terrestrials with low volatile inventories.\u0000We thus note that a substantial dayside/nightside temperature difference alone\u0000does not robustly indicate that a planet does not host an atmosphere and\u0000additional observations and modeling are essential for characterization. We\u0000further discuss several avenues for future study to improve our understanding\u0000of the terrestrial planets and how best to characterize them with JWST.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204559","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 young exoplanetary system TOI-4562: Confirming the presence of a third body in the system","authors":"V. Fermiano, R. K. Saito, V. D. Ivanov, C. Caceres, L. A. Almeida, J. Aires, J. C. Beamin, D. Minniti, T. Ferreira, L. Andrade, B. W. Borges, L. de Almeida, F. Jablonski, W. Schlindwein","doi":"arxiv-2409.06924","DOIUrl":"https://doi.org/arxiv-2409.06924","url":null,"abstract":"Young planetary systems represent an opportunity to investigate the early\u0000stages of (exo)planetary formation because the gravitational interactions have\u0000not yet significantly changed the initial configuration of the system. TOI-4562\u0000b is a highly eccentric temperate Jupiter analogue orbiting a young F7V-type\u0000star of $<700$ Myr in age with an orbital period of $P_{orb} sim 225$ days and\u0000an eccentricity of $e=0.76$, and is one of the largest known exoplanets to have\u0000formed in situ. We observed a new transit of TOI-4562 b using the 0.6-m Zeiss\u0000telescope at the Pico dos Dias Observatory (OPD/LNA) in Minas Gerais, Brazil,\u0000and combine our data with Transiting Exoplanet Survey Satellite (TESS) and\u0000archive data, with the aim being to improve the ephemerides of this interesting\u0000system. The $O-C$ diagram for the new ephemeris is consistent with the presence\u0000of a giant planet in an outer orbit around TOI-4562. TOI-4562 c is a planet\u0000with a mass of $M=5.77 M_{Jup}$, an orbital period of $P_{orb}= 3990$ days, and\u0000a semi-major axis of $a = 5.219$ AU. We report the discovery of TOI-4562 c, the\u0000exoplanet with the longest orbital period discovered to date via the transit\u0000timing variation (TTV) method. The TOI-4562 system is in the process of violent\u0000evolution with intense dynamical changes - judging by its young age and high\u0000eccentricity - and is therefore a prime target for studies of formation and\u0000evolution of planetary systems.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204562","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":"How external photoevaporation changes the inner disc's chemical composition","authors":"Nelson Ndugu, Bertram Bitsch, Lienert Julia Lena","doi":"arxiv-2409.07596","DOIUrl":"https://doi.org/arxiv-2409.07596","url":null,"abstract":"Stars mostly form in clusters where neighboring stars can influence\u0000proto-planetary disc evolution. Besides gravitational interactions, external\u0000photoevaporation can shape these discs. Depending on the strength of\u0000photoevaporation, discs can be destroyed within 1-2 Myrs or more gradually. We\u0000use the chemcomp code, incorporating a viscous disc evolution model with pebble\u0000drift and evaporation, to calculate the chemical composition of protoplanetary\u0000discs. This code is extended to include external photoevaporation based on the\u0000FRIED grid. Initially, the disc evolves purely viscously, with the inner disc's\u0000C/O ratio decreasing due to inward drifting and evaporating water ice pebbles.\u0000Over time, the C/O ratio increases as water vapor accretes onto the star and\u0000carbon-rich gas migrates inward. Once external photoevaporation starts, the\u0000outer disc disperses, but the inner disc's chemical evolution follows that of a\u0000purely viscous disc, as most pebbles have already drifted inward within 1 Myr.\u0000At low viscosity, the inner disc's C/O ratio remains sub-solar until dispersion\u0000by photoevaporation. At high viscosity, the C/O ratio can reach super-solar\u0000values, due to faster accretion of water vapor and inward migration of\u0000carbon-rich gas, provided the disc survives a few Myrs. In both cases, there is\u0000no significant difference in the inner disc's chemical composition compared to\u0000a purely viscous model due to the rapid inward drift of pebbles. Our model\u0000predicts that inner disc chemistry should be similar for discs subject to\u0000external photoevaporation and isolated discs, consistent with JWST\u0000observations.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204556","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":"JWST COMPASS: The 3-5 Micron Transmission Spectrum of the Super-Earth L 98-59 c","authors":"Nicholas Scarsdale, Nicholas Wogan, Hannah R. Wakeford, Nicole L. Wallack, Natasha E. Batalha, Lili Alderson, Artyom Aguichine, Angie Wolfgang, Johanna Teske, Sarah E. Moran, Mercedes Lopez-Morales, James Kirk, Tyler Gordon, Peter Gao, Natalie M. Batalha, Munazza K. Alam, Jea Adams Redai","doi":"arxiv-2409.07552","DOIUrl":"https://doi.org/arxiv-2409.07552","url":null,"abstract":"We present a JWST NIRSpec transmission spectrum of the super-Earth exoplanet\u0000L 98-59 c. This small (R$_p=1.385pm0.085$R$_oplus$,\u0000M$_p=2.22pm0.26$R$_oplus$), warm (T$_textrm{eq}=553$K) planet resides in a\u0000multi-planet system around a nearby, bright (J = 7.933) M3V star. We find that\u0000the transmission spectrum of L 98-59 c is featureless at the precision of our\u0000data. We achieve precisions of 22ppm in NIRSpec G395H's NRS1 detector and 36ppm\u0000in the NRS2 detector at a resolution R$sim$200 (30 pixel wide bins). At this\u0000level of precision, we are able rule out primordial H$_2$-He atmospheres across\u0000a range of cloud pressure levels up to at least $sim$0.1mbar. By comparison to\u0000atmospheric forward models, we also rule out atmospheric metallicities below\u0000$sim$300$times$ solar at 3$sigma$ (or equivalently, atmospheric mean\u0000molecular weights below $sim$10~g/mol). We also rule out pure methane\u0000atmospheres. The remaining scenarios that are compatible with our data include\u0000a planet with no atmosphere at all, or higher mean-molecular weight\u0000atmospheres, such as CO$_2$- or H$_2$O-rich atmospheres. This study adds to a\u0000growing body of evidence suggesting that planets $lesssim1.5$R$_oplus$ lack\u0000extended atmospheres.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204558","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":"Validation of up to seven TESS planet candidates through multi-colour transit photometry using MuSCAT2 data","authors":"A. Peláez-Torres, E. Esparza-Borges, E. Pallé, H. Parviainen, F. Murgas, G. Morello, M. R. Zapatero-Osorio, J. Korth, N. Narita, A. Fukui, I. Carleo, R. Luque, N. Abreu García, K. Barkaoui, A. Boyle, V. J. S. Béjar, Y. Calatayud-Borras, D. V. Cheryasov, J. L. Christiansen, D. R. Ciardi, G. Enoc, Z. Essack, I. Fukuda, G. Furesz, D. Galán, S. Geraldía-González, S. Giacalone, H. Gill, E. J. Gonzales, Y. Hayashi, K. Ikuta, K. Isogai, T. Kagetani, Y. Kawai, K. Kawauchi, P. Klagyvik, T. Kodama, N. Kusakabe, A. Laza-Ramos, J. P. de Leon, J. H. Livingston, M. B. Lund, A. Madrigal-Aguado, P. Meni, M. Mori, S. Muñoz Torres, J. Orell-Miquel, M. Puig, G. Ricker, M. Sánchez-Benavente, A. B. Savel, J. E. Schlieder, R. P. Schwarz, R. Sefako, P. Sosa-Guillén, M. Stangret, C. Stockdale, M. Tamura, Y. Terada, J. D. Twicken, N. Watanabe, J. Winn, S. G. Zheltoukhov, C. Ziegler, Y. Zou","doi":"arxiv-2409.07400","DOIUrl":"https://doi.org/arxiv-2409.07400","url":null,"abstract":"The TESS mission searches for transiting exoplanets by monitoring the\u0000brightness of hundreds of thousands of stars across the entire sky. M-type\u0000planet hosts are ideal targets for this mission due to their smaller size and\u0000cooler temperatures, which makes it easier to detect smaller planets near or\u0000within their habitable zones. Additionally, M~dwarfs have a smaller contrast\u0000ratio between the planet and the star, making it easier to measure the planet's\u0000properties accurately. Here, we report the validation analysis of 13 TESS\u0000exoplanet candidates orbiting around M dwarfs. We studied the nature of these\u0000candidates through a multi-colour transit photometry transit analysis using\u0000several ground-based instruments (MuSCAT2, MuSCAT3, and LCO-SINISTRO),\u0000high-spatial resolution observations, and TESS light curves. We present the\u0000validation of five new planetary systems: TOI-1883b, TOI-2274b, TOI2768b,\u0000TOI-4438b, and TOI-5319b, along with compelling evidence of a planetary nature\u0000for TOIs 2781b and 5486b. We also present an empirical definition for the\u0000Neptune desert boundaries. The remaining six systems could not be validated due\u0000to large true radius values overlapping with the brown dwarf regime or,\u0000alternatively, the presence of chromaticity in the MuSCAT2 light curves.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204560","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 K2 and TESS Synergy III: search and rescue of the lost ephemeris for K2's first planet","authors":"Erica Thygesen, Joseph E. Rodriguez, Zoë L. De Beurs, Andrew Vanderburg, John H. Livingston, Jonathon Irwin, Alexander Venner, Michael Cretignier, Karen A. Collins, Allyson Bieryla, David Charbonneau, Ian J. M. Crossfield, Xavier Dumusque, John Kielkopf, David W. Latham, Michael Werner","doi":"arxiv-2409.07019","DOIUrl":"https://doi.org/arxiv-2409.07019","url":null,"abstract":"K2-2 b/HIP 116454 b, the first exoplanet discovery by K2 during its\u0000Two-Wheeled Concept Engineering Test, is a sub-Neptune (2.5 $pm$ 0.1\u0000$R_oplus$, 9.7 $pm$ 1.2 $M_oplus$) orbiting a relatively bright (KS = 8.03)\u0000K-dwarf on a 9.1 day period. Unfortunately, due to a spurious follow-up transit\u0000detection and ephemeris degradation, the transit ephemeris for this planet was\u0000lost. In this work, we recover and refine the transit ephemeris for K2-2 b,\u0000showing a $sim40{sigma}$ discrepancy from the discovery results. To\u0000accurately measure the transit ephemeris and update the parameters of the\u0000system, we jointly fit space-based photometric observations from NASA's K2,\u0000TESS, and Spitzer missions with new photometric observations from the ground,\u0000as well as radial velocities from HARPS-N that are corrected for stellar\u0000activity using a new modeling technique. Ephemerides becoming lost or\u0000significantly degraded, as is the case for most transiting planets, highlights\u0000the importance of systematically updating transit ephemerides with upcoming\u0000large efforts expected to characterize hundreds of exoplanet atmospheres. K2-2\u0000b sits at the high-mass peak of the known radius valley for sub-Neptunes, and\u0000is now well-suited for transmission spectroscopy with current and future\u0000facilities. Our updated transit ephemeris will ensure no more than a 13-minute\u0000uncertainty through 2030.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"50 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204561","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}