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        <title>Frontiers in Astronomy and Space Sciences | Exoplanets section | New and Recent Articles</title>
        <link>https://www.frontiersin.org/journals/astronomy-and-space-sciences/sections/exoplanets</link>
        <description>RSS Feed for Exoplanets section in the Frontiers in Astronomy and Space Sciences journal | New and Recent Articles</description>
        <language>en-us</language>
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        <pubDate>2026-05-14T01:15:45.393+00:00</pubDate>
        <ttl>60</ttl>
        <item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2026.1736938</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2026.1736938</link>
        <title><![CDATA[Planet formation constraints from exoplanet population synthesis and simulation based inference]]></title>
        <pubdate>2026-04-10T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Jason Ran</author><author>Mihkel Kama</author><author>Anna Sommerville-Thomas</author>
        <description><![CDATA[This work introduces a statistical framework to obtain Bayesian constraints on planet formation parameters, which offers a probabilistic interpretation of uncertainties and degeneracies contained within planet formation models. The model likelihood, or the probability distribution of observations conditioned on a set of formation parameters, is intractable for planet formation theories due to the high degrees of complexity involved. Furthermore, traditional likelihood estimation techniques scale poorly high to dimensional parameter spaces, and begin to require an excessive number of samples. Instead, this work utilizes neural density estimation to directly learn the posterior distribution. This is a data driven simulation-based inference approach based on simulations from an exoplanet population synthesis model. This work focuses on understanding the degeneracies found within the parameters of disk mass, disk radius, MHD-wind parameters, mid-plane temperature, and planet birth location. The information within these degeneracies are captured in posterior distributions conditioned on observables of planet mass, orbital period, and atmospheric C/O ratio. As a realized demonstration, inference is performed on the hot Jupiter HD 209458b. The inferred posterior distribution is re-sampled as parameter inputs for the population synthesis model to re-simulate formation tracks of HD 209458b. These tracks reveal two distinct scenarios where the planet formation begins either side of the CO2 ice line. This highlights the ability to both infer formation parameters, and study the interactions between physical processes involved in planet formation.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2025.1609140</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2025.1609140</link>
        <title><![CDATA[A review of the construction of the supporting energy system for the lunar base]]></title>
        <pubdate>2025-07-02T00:00:00Z</pubdate>
        <category>Review</category>
        <author>Song Lei</author><author>Zhang Guoqing</author><author>Wang Yaohui</author><author>Wang Chang</author><author>Liu Bo</author>
        <description><![CDATA[Since the 20th century, humanity has entered the era of deep - space exploration. The Moon, being close to Earth, is a key target. Building a lunar base is crucial for space exploration and resource use, but requires a reliable energy system. Existing lunar energy system plans usually concentrate on one or two techs and lack a full - scale analysis of long - term, stable, and adequate energy solutions. This review fills the gap. First, it analyzes lunar environmental conditions like extreme temperature swings, vacuum, and radiation. Then, it offers a detailed historical look at lunar exploration, emphasizing progress from Apollo, Luna, and Chang'E. Next, it delves into eight key lunar-base-suitable energy systems: photovoltaic, solar thermal, thermal, controlled nuclear fusion, nuclear fission reactors, radioisotope thermoelectric generators, fuel cells, and electrostatic power. It carefully weighs each system’s pros and cons regarding energy efficiency, environmental adaptability, and technological viability. Finally, it suggests a phased strategy, integrating different technologies for various base - building stages, aiming to provide a comprehensive framework for future lunar energy system design.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2024.1412323</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2024.1412323</link>
        <title><![CDATA[Exploring radio emissions from confirmed exoplanets using SKA]]></title>
        <pubdate>2024-12-02T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Fatemeh Bagheri</author><author>Anshuman Garga</author><author>Ramon E. Lopez</author>
        <description><![CDATA[Our understanding of magnetic fields in exoplanets remains limited compared to those within our solar system. Planets with magnetic fields emit radio signals primarily due to the Electron Cyclotron Maser Instability mechanism. In this study, we explore the feasibility of detecting radio emissions from exoplanets using the Square Kilometre Array (SKA) radio telescope. Utilizing data from the NASA Exoplanet Archive, we compile information on confirmed exoplanets and estimate their radio emissions using the RBL model. Our analysis reveals that four exoplanets—Qatar-4 b, TOI-1278 b, CoRoT-10 b, and HAT-P-20 b—potentially exhibit radio signals suitable for observation with the SKA telescope.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2024.1398379</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2024.1398379</link>
        <title><![CDATA[A fresh look into the interaction of exoplanets magnetosphere with stellar winds using MHD simulations]]></title>
        <pubdate>2024-08-21T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Fatemeh Bagheri</author><author>Ramon Lopez</author><author>Kevin Pham</author>
        <description><![CDATA[Numerous numerical studies have been carried out in recent years that simulate different aspects of exoplanets’ magnetosphere and stellar winds. These studies have focused primarily on hot Jupiters with sun-like stars. This study addresses the challenges inherent in utilizing existing MHD codes to model hot Jupiter-star systems. Due to the scaling of the system and the assumption of a uniformly flowing stellar wind at the outer boundary of the simulation, MHD codes necessitate a minimum distance of greater than 0.4 au for a Jupiter-like planet orbiting a sun-like star to avoid substantial violations of the code’s assumptions. Additionally, employing the GAMERA (Grid Agnostic MHD for Extended Research Applications) MHD code, we simulate star-planet interactions considering various stellar types (Sun-like and M Dwarf stars) with both Jupiter-like and rocky planets positioned at varying orbital distances. Furthermore, we explore the impact of tidal locking on the total power within the magnetosphere-ionosphere systems.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2024.1400032</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2024.1400032</link>
        <title><![CDATA[Infrared-radio-follow-up observations for detection of the magnetic radio emission of extra solar planets: a new window to detect exoplanets]]></title>
        <pubdate>2024-07-08T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Fatemeh Bagheri</author><author>Ramon E. Lopez</author><author>Amir Shahmoradi</author>
        <description><![CDATA[There are several methods for indirectly detecting exoplanets, such as transit, radial velocity, astrometry, and the conventional gravitational microlensing approach. These methods rely on observing the effects of exoplanets on the emission or motion of observed stars. All these techniques have focused on the optical or infrared domains. However, an alternative method for exoplanet detection via microlensing events involves planets orbiting the source star, creating a binary source system. In this study, we explore a novel approach to detecting and studying exoplanets exclusively through their radio emissions resulting from magnetospheric processes. We propose utilizing the Roman telescope as a survey observer to detect microlensing events. Subsequently, we investigate the potential for detecting planetary radio signals through follow-up observations of these microlensing events in the radio band using the SKA telescope. This method is viable due to the comparable radio emission levels of exoplanets and their parent stars, unlike optical and infrared emissions. We conduct a Monte Carlo simulation to replicate the observations by the Nancy Roman Telescope, followed by a follow-up observation in radio frequencies using the SKA telescope. We determine that approximately 1,317 exoplanets exhibit detectable signals by the SKA telescope during the 7-season observations by the Nancy Roman Telescope. This result indicates that such a method cannot only facilitate the direct detection of exoplanets but also enable the measurement of their magnetic field strength through analysis of their radio emissions.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2023.1179000</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2023.1179000</link>
        <title><![CDATA[Warm giant exoplanet characterisation: current state, challenges and outlook]]></title>
        <pubdate>2023-05-10T00:00:00Z</pubdate>
        <category>Mini Review</category>
        <author>Simon Müller</author><author>Ravit Helled</author>
        <description><![CDATA[The characterisation of giant exoplanets is crucial to constrain giant planet formation and evolution theory and for putting the solar-system’s giant planets in perspective. Typically, mass-radius (M-R) measurements of moderately irradiated warm Jupiters are used to estimate the planetary bulk composition, which is an essential quantity for constraining giant planet formation, evolution and structure models. The successful launch of the James Webb Space Telescope (JWST) and the upcoming ARIEL mission open a new era in giant exoplanet characterisation as atmospheric measurements provide key information on the composition and internal structure of giant exoplanets. In this review, we discuss how giant planet evolution models are used to infer the planetary bulk composition, and the connection between the compositions of the interior and atmosphere. We identify the important theoretical uncertainties in evolution models including the equations of state, atmospheric models, chemical composition, interior structure and main energy transport processes. Nevertheless, we show that atmospheric measurements by JWST and ARIEL and the accurate determination of stellar ages by PLATO can significantly reduce the degeneracy in the inferred bulk composition. Furthermore, we discuss the importance of evolution models for the characterisation of direct-imaged planets. We conclude that giant planet theory has a critical role in the interpretation of observation and emphasise the importance of advancing giant planet theory.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2022.823227</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2022.823227</link>
        <title><![CDATA[Hydrocarbon chemistry in the atmosphere of a Warmer Exo-Titan]]></title>
        <pubdate>2022-09-19T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Danica Adams</author><author>Yangcheng Luo</author><author>Yuk L. Yung</author>
        <description><![CDATA[Hosting a ∼1.5 bar N2 atmosphere and reducing atmospheric composition, Titan has the energy sources needed to drive disequilibrium chemistry and hosts an aerosol layer which shields the surface from incident UV radiation. This world draws parallels to an early Earth-like world (although ∼200 K cooler), and the atmospheric chemistry may be capable of forming relevant prebiotic species. Exo-Titan worlds at close-in orbits host photochemistry relevant to habitability with rich hydrocarbon chemistry. We investigate the effect of stellar type of the host star, equilibrium temperature, incident radiation, and vertical transport efficiency on the production of higher-order hydrocarbons. We find a greater incident radiation (a closer orbit) increases the rate of methane photolysis as well as photolysis of hydrocarbons. A larger H2 abundance and warmer temperature increases the rate of the back reaction H2 + CH3 → CH4 + H, and the temperature dependence is so great that CH3 recycles back into CH4 instead of forming C2H6. A larger H2 abundance and warmer temperature also encourages interesting cycling between C2H2, C2H3, and C2H4via reactions with atomic H.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2022.801873</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2022.801873</link>
        <title><![CDATA[Doppler-Shifted Alkali D Absorption as Indirect Evidence for Exomoons]]></title>
        <pubdate>2022-03-16T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Carl A. Schmidt</author>
        <description><![CDATA[Sodium and potassium signatures in transiting exoplanets can be challenging to isolate from the stellar absorption lines. Here, these challenges are discussed in the framework of Solar System observations, and transits of Mercury in particular. Radiation pressure is important for alkali gas dynamics in close-orbiting exoplanets since the D lines are efficient at resonant scattering. When the star-planet velocity is ≳10 km/s, eccentric exoplanets experience more than an order of magnitude higher radiation pressures, aiding atmospheric escape and producing a larger effective cross-section for absorbing starlight at the phase of transit. The Doppler shift also aids in isolating the planetary signature from the stellar photosphere’s absorption. Only one transiting exoplanet, HD 80606b, is presently thought to have both this requisite Doppler shift and alkali absorption. Radiation pressure on a planetary exosphere naturally produces blue-shifted absorption, but at levels insufficient to account for the extreme Doppler shifts that have been inferred from potassium transit measurements of this system. In the absence of clear mechanisms to generate such a strong wind, it is described how this characteristic could arise from an exomoon-magnetosphere interaction, analogous to Io-Jupiter. At low contrasts presented here, follow-up transit spectra of HD 80606b cannot rule out a potassium jet or atmospheric species with a broad absorption structure. However, it is evident that line absorption within the imaging passbands fails to explain the narrow-band photometry that has been reported in-transit. New observations of energetic alkalis produced by the Io-Jupiter interaction are also presented, which illustrate that energetic sodium Doppler structure offers a more valuable marker for the presence of an exomoon than potassium.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2022.819933</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2022.819933</link>
        <title><![CDATA[A Self-Gravitating Exoring Around J1407b and Implications for In-Situ Exomoon Formation]]></title>
        <pubdate>2022-03-14T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Phil J Sutton</author><author>Brayden Albery</author><author>Jake Muff</author>
        <description><![CDATA[We perform simulations of the M⊕ self-gravitating exoring thought to orbit the large exoplanet J1407b. We use a mass of MJ1407b=20MJ (which is close to the revised upper limit) and a semi-major axis of a=5AU, equating to an orbital period of ∼11yrs about the primary. As J1407b is expected to have a high eccentricity, we test eight different models: where e = 0.2, 0.4, 0.6 and 0.8 in both the prograde and retrograde configurations. All prograde models show a strongly perturbed ring within the first orbit. As expected, the retrograde rings demonstrate a higher degree of stability, with the lower eccentricity models (e = 0.2 and 0.4) able to survive multiple orbits. However, even the higher eccentricity (e = 0.6 and 0.8) retrograde models quickly result in the loss of the ring after 200 years. Excitation of eccentricities in all retrograde rings are stable to gravitational collapse. When assuming the most recent mass estimate of MJ1407b=20MJ the ring is unfavourable to the accretion of moons when J1407b is on an elliptical orbit. An interesting consequence of the strong perturbation for one model (retrograde and e = 0.6) during the first close passage is a transient gap located at 0.4AU. This is the same location as the inferred gap from the single transit in 2007 and does not require a nearby exomoon.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2021.830980</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2021.830980</link>
        <title><![CDATA[Editorial: The Effect of Stellar Multiplicity on Exoplanetary Systems]]></title>
        <pubdate>2022-02-14T00:00:00Z</pubdate>
        <category>Editorial</category>
        <author>Steve B. Howell</author><author>Rachel A. Matson</author><author>Francesco Marzari</author>
        <description></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2021.795040</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2021.795040</link>
        <title><![CDATA[High Accuracy Molecular Line Lists for Studies of Exoplanets and Other Hot Atmospheres]]></title>
        <pubdate>2022-01-03T00:00:00Z</pubdate>
        <category>Mini Review</category>
        <author>Jonathan Tennyson</author><author>Sergey N. Yurchenko</author>
        <description><![CDATA[The desire to characterize and model the atmospheres of the many extrasolar planets that have been discovered over the last three decades is a major driver of current astronomy. However, this goal is impacted by the lack of spectroscopic data on the molecules in question. As most atmospheres that can be studied are hot, some surprisingly so, this activity requires spectroscopic information not readily available from laboratory studies. This article will review the current status of available molecular spectroscopic data, usually presented as line lists, for studies of exoplanet atmospheres and, indeed, the atmospheres of other astronomical objects hotter than the Earth such as brown dwarfs, cool stars and even sunspots. Analysis of exoplanet transit spectra and the calculation of the relevant opacities often require huge datasets comprising billions of individual spectroscopic transitions. Conversely, the newly-developed high-resolution Doppler-shift spectroscopy technique has proved to be a powerful tool for detecting molecular species in exoplanet atmospheres, but relies on the use of smaller, highly accurate line lists. Methods of resolving issues arising from the competing demands of completeness versus accuracy for line lists are discussed.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2021.792823</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2021.792823</link>
        <title><![CDATA[Orbital Period Refinement of CoRoT Planets with TESS Observations]]></title>
        <pubdate>2021-12-03T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Peter Klagyivik </author><author>Hans J. Deeg </author><author>Szilárd Csizmadia </author><author>Juan Cabrera </author><author>Grzegorz Nowak </author>
        <description><![CDATA[CoRoT was the first space mission dedicated to exoplanet detection. Operational between 2007 and 2012, this mission discovered 37 transiting planets, including CoRoT-7b, the first terrestrial exoplanet with a measured size. The precision of the published transit ephemeris of most of these planets has been limited by the relative short durations of the CoRoT pointings, which implied a danger that the transits will become unobservable within a few years due to the uncertainty of their future transit epochs. Ground-based follow-up observations of the majority of the CoRoT planets have been published in recent years. Between Dec. 2018 and Jan. 2021, the TESS mission in its sectors 6 and 33 re-observed those CoRoT fields that pointed towards the Galactic anti-center. These data permitted the identification of transits from nine of the CoRoT planets, and the derivation of precise new transit epochs. The main motivation of this study has been to derive precise new ephemerides of the CoRoT planets, in order to keep these planets’ transits observable for future generations of telescopes. The TESS data were analyzed for the presence of transits and the epochs of these re-observed transits were measured. The original CoRoT epochs, epochs from ground-based follow-up observations and those from TESS were collected. From these data, updated ephemerides are presented for nine transiting planets discovered by the CoRoT mission in its fields pointing towards the Galactic anti-center. In three cases (CoRoT-4b, 19b and 20b), transits that would have been lost for ground observations, due to the large uncertainty in the previous ephemeris, have been recovered. The updated ephemerides permit transit predictions with uncertainties of less than 30 min for observations at least until the year 2030. No significant transit timing variations were found in these systems.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2021.769371</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2021.769371</link>
        <title><![CDATA[No Transits of Proxima Centauri Planets in High-Cadence TESS Data]]></title>
        <pubdate>2021-11-19T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Emily A. Gilbert</author><author>Thomas Barclay</author><author>Ethan Kruse</author><author>Elisa V. Quintana</author><author>Lucianne M. Walkowicz</author>
        <description><![CDATA[Proxima Centauri is our nearest stellar neighbor and one of the most well-studied stars in the sky. In 2016, a planetary companion was detected through radial velocity measurements. Proxima Centauri b has a minimum mass of 1.3 Earth masses and orbits with a period of 11.2 days at 0.05 AU from its stellar host, and resides within the star’s Habitable Zone. While recent work has shown that Proxima Centauri b likely does not transit, given the value of potential atmospheric observations via transmission spectroscopy of the closest possible Habitable Zone planet, we reevaluate the possibility that Proxima Centauri b is a transiting exoplanet using data from the Transiting Exoplanet Survey Satellite (TESS). We use three sectors (Sectors 11, 12, and 38 at 2-min cadence) of observations from TESS to search for planets. Proxima Centauri is an extremely active M5.5 star, emitting frequent white-light flares; we employ a novel method that includes modeling the stellar activity in our planet search algorithm. We do not detect any planet signals. We injected synthetic transiting planets into the TESS and use this analysis to show that Proxima Centauri b cannot be a transiting exoplanet with a radius larger than 0.4 R⊕. Moreover, we show that it is unlikely that any Habitable Zone planets larger than Mars transit Proxima Centauri.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2021.696011</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2021.696011</link>
        <title><![CDATA[Corrigendum: The NASA High-Resolution Speckle Interferometric Imaging Program: Validation and Characterization of Exoplanets and Their Stellar Hosts]]></title>
        <pubdate>2021-09-30T00:00:00Z</pubdate>
        <category>Correction</category>
        <author>Steve B. Howell</author><author>Nicholas J. Scott</author><author>Rachel A. Matson</author><author>Mark E. Everett</author><author>Elise Furlan</author><author>Crystal L. Gnilka</author><author>David R. Ciardi</author><author>Kathryn V. Lester</author>
        <description></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2021.708023</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2021.708023</link>
        <title><![CDATA[Asymmetry and Variability in the Transmission Spectra of Tidally Locked Habitable Planets]]></title>
        <pubdate>2021-09-22T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Xinyi Song</author><author>Jun Yang</author>
        <description><![CDATA[Spatial heterogeneity and temporal variability are general features in planetary weather and climate, due to the effects of planetary rotation, uneven stellar flux distribution, fluid motion instability, etc. In this study, we investigate the asymmetry and variability in the transmission spectra of 1:1 spin–orbit tidally locked (or called synchronously rotating) planets around low-mass stars. We find that for rapidly rotating planets, the transit atmospheric thickness of the evening terminator (east of the substellar region) is significantly larger than that of the morning terminator (west of the substellar region). The asymmetry is mainly related to the spatial heterogeneity in ice clouds, as the contributions of liquid clouds and water vapor are smaller. The underlying mechanism is that there are always more ice clouds on the evening terminator, due to the combined effect of coupled Rossby–Kelvin waves and equatorial superrotation that advect vapor and clouds to the east, especially at high levels of the atmosphere. For slowly rotating planets, the asymmetry reverses (the morning terminator has a larger transmission depth than the evening terminator), but the magnitude is small or even negligible. For both rapidly and slowly rotating planets, there is strong variability in the transmission spectra. The asymmetry signal is nearly impossible to be observed by the James Webb Space Telescope (JWST), because the magnitude of the asymmetry (about 10 ppm) is smaller than the instrumental noise and the high variability further increases the challenge.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2021.628396</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2021.628396</link>
        <title><![CDATA[Follow-Up and Validation of K2 and TESS Planetary Systems With Keck NIRC2 Adaptive Optics Imaging]]></title>
        <pubdate>2021-06-23T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Joshua E. Schlieder</author><author>Erica J. Gonzales</author><author>David R. Ciardi</author><author>Rahul I. Patel</author><author>Ian J. M. Crossfield</author><author>Justin R. Crepp</author><author>Courtney D. Dressing</author><author>Thomas Barclay</author><author>Andrew W. Howard</author>
        <description><![CDATA[High resolution imaging (HRI) is a critical part of the transiting exoplanet follow-up and validation process. HRI allows previously unresolved stellar companions and background blends to be resolved, vetting false positive signals and improving the radii measurements of true planets. Through a multi-semester Keck NIRC2 adaptive optics imaging program, we have pursued HRI of K2 and TESS candidate planet host systems to provide the transiting exoplanet community with necessary data for system validation and characterization. Here we present a summary of our ongoing program that includes an up to date list of targets observed, a description of the observations and data reduction, and a discussion of planetary systems validated by the community using these data. This observing program has been key in NASA's K2 and TESS missions reaching their goals of identifying new exoplanets ideal for continued follow-up observations to measure their masses and investigate their atmospheres. Once processed, all observations presented here are available as calibrated images and resulting contrast curves through the Exoplanet Follow-up Observing Program (ExoFOP) website. We encourage members of the exoplanet community to use these data products in their ongoing planetary system validation and characterization efforts.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2021.625552</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2021.625552</link>
        <title><![CDATA[Binary Gravitational Perturbations and Their Influence on the Habitability of Circumstellar Planets]]></title>
        <pubdate>2021-04-20T00:00:00Z</pubdate>
        <category>Review</category>
        <author>Elke Pilat-Lohinger</author><author>Ákos Bazsó</author>
        <description><![CDATA[In order to assess the habitability of planets in binary star systems, not only astrophysical considerations regarding stellar and atmospheric conditions are needed, but orbital dynamics and the architecture of the system also play an important role. Due to the strong gravitational perturbations caused by the presence of the second star, the study of planetary orbits in double star systems requires special attention. In this context, we show the important role of the main gravitational perturbations (resonances) and review our recently developed methods which allow a quick determination of locations of secular resonances (SRs) in binary stars for circumstellar planetary motion where a giant planet has to move exterior to the habitable zone (HZ). These methods provide the basis for our online-tool ShaDoS which allows a quick check of circumstellar HZs regarding secular perturbations. It is important to know the locations of SRs since they can push a dynamically quiet HZ into a high-eccentricity state which will change the conditions for habitability significantly. Applications of SHaDoS to the wide binary star HD106515 AB and the tight system HD41004 AB reveal a quiet HZ for both systems. However, the study of these systems indicates only for the tight binary star a possible change of the HZ's dynamical state if the orbital parameters change due to new observational data.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2021.640830</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2021.640830</link>
        <title><![CDATA[Circumbinary Habitable Zones in the Presence of a Giant Planet]]></title>
        <pubdate>2021-04-15T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Nikolaos Georgakarakos</author><author>Siegfried Eggl</author><author>Ian Dobbs-Dixon</author>
        <description><![CDATA[Determining habitable zones in binary star systems can be a challenging task due to the combination of perturbed planetary orbits and varying stellar irradiation conditions. The concept of “dynamically informed habitable zones” allows us, nevertheless, to make predictions on where to look for habitable worlds in such complex environments. Dynamically informed habitable zones have been used in the past to investigate the habitability of circumstellar planets in binary systems and Earth-like analogs in systems with giant planets. Here, we extend the concept to potentially habitable worlds on circumbinary orbits. We show that habitable zone borders can be found analytically even when another giant planet is present in the system. By applying this methodology to Kepler-16, Kepler-34, Kepler-35, Kepler-38, Kepler-64, Kepler-413, Kepler-453, Kepler-1647, and Kepler-1661 we demonstrate that the presence of the known giant planets in the majority of those systems does not preclude the existence of potentially habitable worlds. Among the investigated systems Kepler-35, Kepler-38, and Kepler-64 currently seem to offer the most benign environment. In contrast, Kepler-16 and Kepler-1647 are unlikely to host habitable worlds.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2021.625230</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2021.625230</link>
        <title><![CDATA[Robo-AO and SOAR High-Resolution Surveys of Exoplanet Hosting Stars]]></title>
        <pubdate>2021-03-29T00:00:00Z</pubdate>
        <category>Brief Research Report</category>
        <author>Carl Ziegler</author><author>Nicholas Law</author><author>Christoph Baranec</author><author>Reed Riddle</author><author>Andrei Tokovinin</author>
        <description><![CDATA[In the past decade, space-based transit surveys have delivered thousands of potential planet-hosting systems. Each of these needs to be vetted and characterized using follow-up high-resolution imaging. We perform comprehensive imaging surveys of the candidate exoplanets detected by the Kepler and TESS missions using the fully autonomous Robo-AO system and the largely autonomous SOAR speckle imaging system. The surveys yielded hundreds of previously unknown close binary systems hosting exoplanets and resulted in verification of hundreds of exoplanet systems. Evidence of the interaction between binary stars and planetary systems was also detected, including a deep deficit of planets in close binary systems.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2021.624907</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2021.624907</link>
        <title><![CDATA[Search for (sub)stellar Companions of Exoplanet Hosts by Exploring the Second ESA-Gaia Data Release]]></title>
        <pubdate>2021-03-29T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>K.-U. Michel</author><author>M. Mugrauer</author>
        <description><![CDATA[We present the latest results of an ongoing multiplicity survey of exoplanet hosts, which was initiated at the Astrophysical Institute and University Observatory Jena, using data from the second data release of the ESA-Gaia mission. In this study the multiplicity of 289 targets was investigated, all located within a distance of about 500 pc from the Sun. In total, 41 binary, and five hierarchical triple star systems with exoplanets were detected in the course of this project, yielding a multiplicity rate of the exoplanet hosts of about 16%. A total of 61 companions (47 stars, a white dwarf, and 13 brown dwarfs) were detected around the targets, whose equidistance and common proper motion with the exoplanet hosts were proven with their precise Gaia DR2 astrometry, which also agrees with the gravitational stability of most of these systems. The detected companions exhibit masses from about 0.016 up to 1.66 M⊙ and projected separations in the range between about 52 and 9,555 au.]]></description>
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