TrES-1: The Transiting Planet of a Bright K0V Star

We report the detection of a transiting Jupiter-sized planet orbiting a relatively bright (V=11.79) K0V star. We detected the transit light-curve signature in the course of the TrES multi-site transiting planet survey, and confirmed the planetary nature of the companion via multicolor photometry and precise radial velocity measurements. We designate the planet TrES-1; its inferred mass is 0.75 +/- 0.07 Jupiter masses, its radius is 1.08 (+0.18/-0.04) Jupiter radii, and its orbital period is 3.030065 +/- 0.000008 days. This planet has an orbital period similar to that of HD 209458b, but about twice as long as those of the OGLE transiting planets. Its mass is indistinguishable from that of HD 209458b, but its radius is significantly smaller and fits the theoretical models without the need for an additional source of heat deep in the atmosphere, as has been invoked by some investigators for HD 209458b.

We present the discovery of 30 transiting giant planets that were initially detected using data from NASA’s Transiting Exoplanet Survey Satellite mission. These new planets orbit relatively bright ( G ≤ 12.5) FGK host stars with orbital periods between 1.6 and 8.2 days, and have radii between 0.9 and 1.7 Jupiter radii. We performed follow-up ground-based photometry, high angular resolution imaging, high-resolution spectroscopy, and radial velocity monitoring for each of these objects to confirm that they are planets and determine their masses and other system parameters. The planets’ masses span more than an order of magnitude (0.17 M J &lt; M p &lt; 3.3 M J ). For two planets, TOI-3593 b and TOI-4961 b, we measured significant nonzero eccentricities of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>0.1</mml:mn> <mml:msubsup> <mml:mrow> <mml:mn>1</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.03</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.05</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>0.1</mml:mn> <mml:msubsup> <mml:mrow> <mml:mn>8</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.05</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.04</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> , respectively, while for the other planets, the data typically provide a 1 σ upper bound of 0.15 on the eccentricity. These discoveries represent a major step toward assembling a complete, magnitude-limited sample of transiting hot Jupiters around FGK stars.

Astronomers have found more than a dozen planets transiting stars that are 10-40 million years old1, but younger transiting planets have remained elusive. The lack of such discoveries may be because planets have not fully formed at this age or because our view is blocked by the protoplanetary disk. However, we now know that many outer disks are warped or broken2; provided the inner disk is depleted, transiting planets may thus be visible. Here we report observations of the transiting planet IRAS 04125+2902 b orbiting a 3-million-year-old, 0.7-solar-mass, pre-main-sequence star in the Taurus Molecular Cloud. The host star harbours a nearly face-on (30 degrees inclination) transitional disk3 and a wide binary companion. The planet has a period of 8.83 days, a radius of 10.7 Earth radii (0.96 Jupiter radii) and a 95%-confidence upper limit on its mass of 90 Earth masses (0.3 Jupiter masses) from radial-velocity measurements, making it a possible precursor of the super-Earths and sub-Neptunes frequently found around main-sequence stars. The rotational broadening of the star and the orbit of the wide (4 arcseconds, 635 astronomical units) companion are both consistent with edge-on orientations. Thus, all components of the system are consistent with alignment except the outer disk; the origin of this misalignment is unclear.

Simulations with a 3D general circulation model (GCM) suggest that one potential driver behind the observed radius inflation in hot Jupiters may be the downward advection of energy from the highly irradiated photosphere into the deeper layers. Here, we compare dynamical heat transport within the non-inflated hot Jupiter WASP-43b and the canonical inflated hot Jupiter HD 209458b, with similar effective temperatures. We investigate to what extent the radiatively driven heating and cooling in the photosphere (at pressures smaller than 1 bar) influence the deeper temperature profile (at pressures between 1 to 700 bar). Our simulations with the new non-gray 3D radiation-hydrodynamical model expeRT/MITgcm show that the deep temperature profile of WASP-43b is associated with a relatively cold adiabat. The deep layers of HD 209458b, however, do not converge and remain nearly unchanged regardless of whether a cold or a hot initial state is used. Furthermore, we show that different flow structures in the deep atmospheric layers arise. There, we find that WASP-43b exhibits a deep equatorial jet, driven by the relatively fast tidally locked rotation of this planet (0.81 days), as compared to HD 209458b (3.47 days). However, by comparing simulations with different rotation periods, we find that the resulting flow structures only marginally influence the temperature evolution in the deep atmosphere, which is almost completely dominated by radiative heating and cooling. Furthermore, we find that the evolution of deeper layers can influence the 3D temperature structure in the photosphere of WASP-43b. Thus, dayside emission spectra of WASP-43b may shed more light onto the dynamical processes occurring at greater depths.

On the Transport of Material Interior to the Orbit of Io During the Formation of the Galilean Satellites Silvia Giuliatti Winter1, Rafael Ribeiro1, Gustavo Madeira 2, and André Izidoro3 Silvia Giuliatti Winter et al. Silvia Giuliatti Winter1, Rafael Ribeiro1, Gustavo Madeira 2, and André Izidoro3 1São Paulo State University, Faculdade de Engenharia e Ciências, Guaratinguetá, 12516-410, Brazil (giuliatti.winter@unesp.br) 2Observatório Nacional/MCTI, Rio de Janeiro, 20921-400, Brazil 3Department of Earth, Environmental and Planetary Sciences, 6100 Main MS 126, Rice University, Houston, TX 77005, USA 1São Paulo State University, Faculdade de Engenharia e Ciências, Guaratinguetá, 12516-410, Brazil (giuliatti.winter@unesp.br) 2Observatório Nacional/MCTI, Rio de Janeiro, 20921-400, Brazil 3Department of Earth, Environmental and Planetary Sciences, 6100 Main MS 126, Rice University, Houston, TX 77005, USA The so-called Galilean satellites -- Io, Europa, Ganymede, and Callisto -- correspond to a dynamically compact system, with the satellites orbiting in nearly circular and coplanar orbits. The three inner satellites (Io, Europa, Ganymede) are involved in a 4:2:1 mean motion resonance (MMR) chain, while Callisto is situated beyond the 2:1 MMR with Ganymede (Peale, 1999). The current distances of Io, Europa, Ganymede, and Callisto from Jupiter are 5.9RJ, 9.4RJ, 15RJ, and 26.4RJ, respectively (Schubert et al., 2004), where RJ is the radius of Jupiter. All of these satellites have masses on the order of 10-5 masses of Jupiter (MJ). Within the orbit of Io, there is a population of small moons around Jupiter, namely Metis, Adrastea, Amalthea, and Thebe. Metis and Adrastea have sizes approximately around 21.7km and 8.2km, in nearly circular and coplanar orbits. In contrast, Thebe and Amalthea are considerably larger, with diameters of about 49.2km and 83.6km, respectively. These small moons are nearby or embedded in the ring system of Jupiter. The formation and evolution of small satellites remain inconclusive. The goal of this work is to evaluate the efficiency of satellite implantation, during the formation of Galilean satellites, interior to the orbit of Io, focusing on their potential to evolve into orbits similar to those of Jupiter's small inner moons. To achieve this, we performed N-body numerical simulations to model the implantation of satellitesimals, initially distributed between 5RJ and 100RJ, in the region of the small moons (

Studying chemical composition is fundamental to modeling the formation history of planets and planetary systems. With the first JWST data and the upcoming Ariel satellite, we expect a leap forward in the exoplanet&amp;#8217;s atmosphere field. That&amp;#8217;s why we propose here an analysis of five targets to improve the determination of their composition and the chemical mechanisms that take place in their atmospheres, combining multiple instruments and using retrieval methods. Our five targets are HAT-P-12b, HD 209458b, WASP-6b, WASP-17b, and WASP-39b, which have temperatures ranging from 1000K to 1700K and radii ranging from 0.9 to 1.9 Jupiter radius. We use spatially scanned observations from the grisms G102 and G141 of the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope, with a wavelength coverage of 0.8 to 1.7 microns. We analyze these data with the publicly available Iraclis pipeline (Tsiaras et al. (2018)). We added to our datasets Space Telescope Imaging Spectrograph (STIS) observations, reduced and presented in Sing et al. (2015), to increase our wavelength coverage from 0.4 to 1.7 microns. We then perform a Bayesian retrieval analysis with the open-source TauREx (Al-Refaie et al. (2019)) using a nested sampling algorithm. We perform the retrieval considering molecular abundances varying freely and with equilibrium chemistry ACE (Ag&amp;#250;ndez et al. (2012, 2020)) and FastChem (Stock et al. (2018)). The principle is to start from a transmission spectroscopy dataset and to seek the model that characterizes the atmosphere in the most probable way, in other words, the spectrum that best fits the data points. This work is detailed in a dedicated paper published in the Astronomy \&amp;amp; Astrophysics journal (Panek et al. (2023)). For very hot planets, thermochemical equilibrium may be close to reality, but for less hot planets, vertical mixing and photodissociation bring these planets out of equilibrium. That's why our results will soon be extended to a non-equilibrium thermochemistry model (Venot et al. (2020)).

Infrared transmission and emission spectroscopy of exoplanets, recorded from primary transit and secondary eclipse measurements, indicate the presence of the most abundant carbon and oxygen molecular species (H2O, CH4, CO and CO2) in a few exoplanets. However, efforts to constrain the molecular abundances to within several orders of magnitude are thwarted by the broad range of degenerate solutions that fit the data. Here, we explore, with radiative transfer models and analytical approximations, the nature of the degenerate solution sets resulting from the sparse measurements of 'hot Jupiter' exoplanets. As demonstrated with simple analytical expressions, primary transit measurements probe roughly four atmospheric scale heights at each wavelength band. Derived mixing ratios from these data are highly sensitive to errors in the radius of the planet at a reference pressure. For example, an uncertainty of 1% in the radius of a 1000 K and H2-based exoplanet with Jupiter's radius and mass causes an uncertainty of a factor of approximately 100-10,000 in the derived gas mixing ratios. The degree of sensitivity depends on how the line strength increases with the optical depth (i.e. the curve of growth) and the atmospheric scale height. Temperature degeneracies in the solutions of the primary transit data, which manifest their effects through the scale height and absorption coefficients, are smaller. We argue that these challenges can be partially surmounted by a combination of selected wavelength sampling of optical and infrared measurements and, when possible, the joint analysis of transit and secondary eclipse data of exoplanets. However, additional work is needed to constrain other effects, such as those owing to planetary clouds and star spots. Given the current range of open questions in the field, both observations and theory, there is a need for detailed measurements with space-based large mirror platforms (e.g. James web space telescope) and smaller broad survey telescopes as well as ground-based efforts.

KOI-227, KOI-319 and KOI-884 are identified here as (at least) two planet systems. For KOI-319 and KOI-884, the observed Transit Timing Variations (TTVs) of the inner transiting planet are used to detect an outer non-transiting planet. The outer planet in KOI-884 is 2.6 Jupiter masses and has the orbital period just narrow of the 3:1 resonance with the inner planet (orbital period ratio 2.93). The distribution of parameters inferred from KOI-319.01's TTVs is bimodal with either a 1.6 Neptune-mass (M_N) planet wide of the 5:3 resonance (period 80.1 d) or a 1 Saturn-mass planet wide of the 7:3 resonance (period 109.2 d). The radial velocity measurements can be used in this case to determine which of these parameter modes is correct. KOI-227.01's TTVs with large 10 hour amplitude can be obtained for planetary-mass companions in various major resonances. Based on the Bayesian evidence, the current TTV data favor the outer 2:1 resonance with a companion mass 1.5 M_N, but this solution implies a very large density of KOI-227.01. The inner and outer 3:2 resonance solutions with sub-Neptune-mass companions are physically more plausible, but will need to be verified.

Formation of the galilean satellites in a gaseous nebula

We analyse the causes of a discrepancy between the earlier obtained samples of the mass distributions of exoplanets detected by the transit method and the radial velocity (RV) one and corrected for some observational selection effects. It is found that this discrepancy can be removed by introducing the following restrictions into the procedures forming the samples: (i) to consider, among transit exoplanets, only those which masses were determined by the RV method (i.e. excluding the transit time variation method); (ii) to take into account exoplanets with orbital periods P ∈ [1, 100] days and masses M ∈ [0.02, 13]MJ (Jupiter masses). In addition, we compare here the distributions by projective masses (which is Msin i, where i is the orbital inclination of an exoplanet). For this, the mass distribution of transit exoplanets is transformed into the projective mass distribution. Due to these three changes in the procedure, the obtained RV and transit distributions exhibit a similar behaviour in an interval of M ∈ [0.02, Mmid]MJ and coincide at M ∈ [Mmid, 13]MJ, where Mmid ≈ 0.17MJ.

Context. After many attempts over more than a decade, high-resolution spectroscopy has recently delivered its first detections of molecular absorption in exoplanet atmospheres, both in transmission and thermal emission spectra. Targeting the combined signal from individual lines in molecular bands, these measurements use variations in the planet radial velocity to separate the planet signal from telluric and stellar contaminants. Aims. We apply high-resolution spectroscopy to probe molecular absorption in the day-side spectrum of the bright transiting hot Jupiter HD 189733b. Methods. We observed HD 189733b with the CRIRES high-resolution near-infrared spectograph on the Very Large Telescope during three nights, targeting possible absorption from carbon monoxide, water vapour, methane, and carbon dioxide, at 2.0 and 2.3 μm. Results. We detect a 5-σ absorption signal from CO at a contrast level of ~4.5 × 10-4 with respect to the stellar continuum, revealing the planet orbital radial velocity at 154+4-3 km s-1. This allows us to solve for the planet and stellar mass in a similar way as for stellar eclipsing binaries, resulting in 0.846+0.068-0.049M⊙ and Mp = 1.162+0.058-0.039 MJup. No significant absorption is detected from H2O, CO2, or CH4 and we determine upper limits on their line contrasts. Conclusions. The detection of CO in the day-side spectrum of HD 189733b can be made consistent with the haze layer proposed to explain the optical to near-infrared transmission spectrum if the layer is optically thin at the normal incidence angles probed by our observations, or if the CO abundance is high enough for the CO absorption to originate from above the haze. Our non-detection of CO2 at 2.0 μm is not inconsistent with the deep CO2 absorption from low-resolution NICMOS secondary eclipse data in the same wavelength range. If genuine, the absorption would be so strong that it blanks out any planet light completely in this wavelength range, leaving no high-resolution signal to be measured.

We present precision radial velocity (RV) data sets from Keck-HIRES and from Lick Observatory's new Automated Planet Finder Telescope and Levy Spectrometer on Mt. Hamilton that reveal a multiple-planet system orbiting the nearby, slightly evolved, K-type star HD 141399. Our 91 observations over 10.5 years suggest the presence of four planets with orbital periods of 94.35, 202.08, 1070.35, and 3717.35 days and minimum masses of 0.46, 1.36, 1.22, and 0.69 Jupiter masses respectively. The orbital eccentricities of the three inner planets are small, and the phase curves are well sampled. The inner two planets lie just outside the 2:1 resonance, suggesting that the system may have experienced dissipative evolution during the protoplanetary disk phase. The fourth companion is a Jupiter-like planet with a Jupiter-like orbital period. Its orbital eccentricity is consistent with zero, but more data will be required for an accurate eccentricity determination.

Capture Statistics of Short-Period Comets: Implications for Comet D/Shoemaker–Levy 9

We investigate the distribution of mass &lt;it&gt;M&lt;/it&gt; and orbital period &lt;it&gt;P&lt;/it&gt; of extrasolar planets, taking account of selection effects caused by the limited velocity precision and duration of existing surveys. We fit the data on 72 planets to a power-law distribution of the form d&lt;it&gt;n&lt;/it&gt;=&lt;it&gt;CM&lt;/it&gt;−α&lt;it&gt;P&lt;/it&gt;−β(d&lt;it&gt;M&lt;/it&gt;/&lt;it&gt;M&lt;/it&gt;)(d&lt;it&gt;P&lt;/it&gt;/&lt;it&gt;P&lt;/it&gt;), and find α= 0.11 ± 0.10, β=−0.27 ± 0.06 for &lt;it&gt;M&lt;/it&gt;&amp;lsim; 10 &lt;it&gt;M&lt;/it&gt;&lt;inf&gt;J&lt;/inf&gt;, where &lt;it&gt;M&lt;/it&gt;&lt;inf&gt;J&lt;/inf&gt; is the mass of Jupiter. The correlation coefficient between these two exponents is −0.31, indicating that uncertainties in the two distributions are coupled. We estimate that 4 per cent of solar-type stars have companions in the range 1 &lt;it&gt;M&lt;/it&gt;&lt;inf&gt;J&lt;/inf&gt; &lt; &lt;it&gt;M&lt;/it&gt; &lt; 10 &lt;it&gt;M&lt;/it&gt;&lt;inf&gt;J&lt;/inf&gt;, 2&lt;inf&gt;d&lt;/inf&gt; &lt; &lt;it&gt;P&lt;/it&gt; &lt; 10 yr.

From the thousands of known exoplanets, those that transit bright host stars provide the greatest accessibility toward detailed system characterization. The first known such planets were generally discovered using the radial-velocity technique, then later found to transit. HD 17156b is particularly notable among these initial discoveries because it diverged from the typical hot-Jupiter population, occupying a 21.2 day eccentric (e = 0.68) orbit, offering preliminary insights into the evolution of planets in extreme orbits. Here we present new data for this system, including ground- and space-based photometry, radial velocities, and speckle imaging, that further constrain the system properties and stellar/planetary multiplicity. These data include photometry from the Transiting Exoplanet Survey Satellite that cover five transits of the known planet. We show that the system does not harbor any additional giant planets interior to 10 au. The lack of stellar companions and the age of the system indicate that the eccentricity of the known planet may have resulted from a previous planet–planet scattering event. We provide the results from dynamical simulations that suggest possible properties of an additional planet that culminated in ejection from the system, leaving a legacy of the observed high eccentricity for HD 17156b.