Hot Planets Research Articles

Polycyclic Aromatic Hydrocarbons in exoplanet atmospheres: A detectability study

Abstract In this paper, we explore the detectability of polycyclic aromatic hydrocarbons (PAHs) under diverse planetary conditions, aiming to identify promising targets for future observations of planetary atmospheres. Our primary goal is to determine the minimum detectable mass fractions of PAHs on each studied planet. We integrate the one-dimensional self consistent model petitCODE with petitRADTRANS, a radiative transfer model, to simulate the transmission spectra of these planets. Subsequently, we employ the PandExo noise simulator using the NIRSpec PRISM instrument aboard the JWST to assess the observability. Then, we conduct a Bayesian analysis through the MULTINEST code. Our findings illustrate that variations in C/O ratios and planet temperatures significantly influence the transmission spectra and the detectability of PAHs. Our results show that planets with [Fe/H]=0 and 1, C/O=0.55, and temperatures around 1200 K are the most promising for detecting PAHs, with detectable mass fractions as low as 10−7, or one thousandth of the ISM abundance level. For colder planets with lower metallicities and C/O ratios, as well as hotter planets with carbon-rich atmospheres, PAHs can be detected at abundances around 10−6. These results aid our strategy for selecting targets to study PAHs in the atmospheres of exoplanets.

HATS-38 b and WASP-139 b Join a Growing Group of Hot Neptunes on Polar Orbits* * Based on observations made with the ESO telescopes at the La Silla Paranal Observatory under program ID 111.24VT.001, 111.24VT.002, and 112.25W1.001.

We constrain the sky-projected obliquities of two low-density hot Neptune planets, HATS-38 b and WASP-139 b, orbiting nearby G and K stars using Rossiter–McLaughlin (RM) observations with VLT/ESPRESSO, yielding λ=−108−16+11 deg and −85.6−4.2+7.7 deg, respectively. To model the RM effect, we use a new publicly available code, ironman, which is capable of jointly fitting transit photometry, Keplerian radial velocities, and RM effects. WASP-139 b has a residual eccentricity e=0.103−0.041+0.050 while HATS-38 b has an eccentricity of e=0.112−0.070+0.072 , which is compatible with a circular orbit given our data. Using the obliquity constraints, we show that they join a growing group of hot and low-density Neptunes on polar orbits. We use long-term radial velocities to rule out companions with masses ∼0.3–50 M J within ∼10 au. We show that the orbital architectures of the two Neptunes can be explained with high-eccentricity migration from ≳2 au driven by an unseen distant companion. If HATS-38 b has no residual eccentricity, its polar and circular orbit can also be consistent with a primordial misalignment. Finally, we perform a hierarchical Bayesian modeling of the true obliquity distribution of Neptunes and find suggestive evidence for a higher preponderance of polar orbits for hot Neptunes compared to Jupiters. However, we note that the exact distribution is sensitive to the choice of priors, highlighting the need for additional obliquity measurements of Neptunes to robustly compare the hot Neptune obliquity distribution to that of Jupiters.

XUV irradiation of young planetary atmospheres. Results from a joint XMM-Newton and HST observation of HIP67522

The evaporation and the chemistry of the atmospheres of warm and hot planets are strongly determined by the high-energy irradiation they receive from their parent stars. This is more crucial among young extra-solar systems because of the high activity of stars at early ages. In particular, the extreme-ultraviolet (EUV) part of the stellar spectrum drives significant processes of photo-chemical interaction, but it is not directly measurable because of strong interstellar absorption and a lack of sufficiently sensitive instrumentation. An alternative approach is to derive synthetic spectra from the analysis of far-ultraviolet (FUV) and X-ray emission lines, which allow us to estimate the missed flux in the EUV band. We performed joint and simultaneous spectroscopy of with and the Hubble Space Telescope (HST) in order to reconstruct the full high-energy spectrum of this 17\,Myr-old solar-type (G0) star, which is the youngest transiting multiplanet system known to date. We performed a time-resolved spectral analysis of the observations, including quiescent emission and flaring variability. We then derived the emission measure distribution (EMD) versus temperature of the chromospheric and coronal plasma from the high-resolution spectra obtained in X-rays with RGS and in FUV with COS. We derived broad-band X-ray and EUV luminosities from the synthetic spectrum based on the EMD, which allowed us to test alternative EUV versus\ X-ray scaling laws available in the literature. We also employed the total X--EUV flux received by the inner planet of the system to estimate its instantaneous atmospheric mass-loss rate. We confirm that is a very active star with a hot corona, reaching plasma temperatures above 20\,MK even in quiescent state. Its EUV/X-ray flux ratio falls in between the predictions of the two scaling laws we tested, indicating an important spread in the stellar properties, which requires further investigation.

TOI-1685 b Is a Hot Rocky Super-Earth: Updates to the Stellar and Planet Parameters of a Popular JWST Cycle 2 Target

We present an updated characterization of the TOI-1685 planetary system, which consists of a P b = 0.69 day ultra-short-period super-Earth planet orbiting a nearby (d = 37.6 pc) M2.5V star (TIC 28900646, 2MASS J04342248+4302148). This planet was previously featured in two contemporaneous discovery papers, but the best-fit planet mass, radius, and bulk density values were discrepant, allowing it to be interpreted either as a hot, bare rock or a 50% H2O/50% MgSiO3 water world. TOI-1685 b will be observed in three independent JWST Cycle 2 programs, two of which assume the planet is a water world, while the third assumes that it is a hot rocky planet. Here we include a refined stellar classification with a focus on addressing the host star’s metallicity, an updated planet radius measurement that includes two sectors of TESS data and multicolor photometry from a variety of ground-based facilities, and a more accurate dynamical mass measurement from a combined CARMENES, InfraRed Doppler, and MAROON-X radial velocity data set. We find that the star is very metal-rich ([Fe/H] ≃ +0.3) and that the planet is systematically smaller, lower mass, and higher density than initially reported, with new best-fit parameters of R pl = 1.468 −0.051+0.050 R ⊕ and M pl = 3.03−0.32+0.33 M ⊕. These results fall in between the previously derived values and suggest that TOI-1685 b is a hot rocky planet with an Earth-like density (ρ pl = 5.3 ± 0.8 g cm−3, or 0.96 ρ ⊕), high equilibrium temperature (T eq = 1062 ± 27 K), and negligible volatiles, rather than a water world.

Simulating the Escaping Atmosphere of GJ 436 b with Two-fluid Magnetohydrodynamic Models

Observations of transmission spectra reveal that hot Jupiters and Neptunes are likely to possess escaping atmospheres driven by stellar radiation. Numerous models predict that magnetic fields may exert significant influences on the atmospheres of hot planets. Generally, the escaping atmospheres are not entirely ionized, and magnetic fields only directly affect the escape of ionized components within them. Considering the chemical reactions between ionized components and neutral atoms, as well as collision processes, magnetic fields indirectly impact the escape of neutral atoms, thereby influencing the detection signals of planetary atmospheres in transmission spectra. In order to simulate this process, we developed a magnetohydrodynamic multi-fluid model based on MHD code PLUTO. As an initial exploration, we investigated the impact of magnetic fields on the decoupling of H+ and H in the escaping atmosphere of the hot Neptune GJ436b. Due to the strong resonant interactions between H and H+, the coupling between them is tight even if the magnetic field is strong. Of course, alternatively, our work also suggests that merging H and H+ into a single flow can be a reasonable assumption in MHD simulations of escaping atmospheres. However, our simulation results indicate that under the influence of magnetic fields, there are noticeable regional differences in the decoupling of H+ and H. With the increase of magnetic field strength, the degree of decoupling also increases. For heavier particles such as O, the decoupling between O and H+ is more pronounced. Our findings provide important insights for future studies on the decoupling processes of heavy atoms in the escaping atmospheres of hot Jupiters and hot Neptunes under the influence of magnetic fields.

Revealing H2O dissociation in WASP-76 b through combined high- and low-resolution transmission spectroscopy

ABSTRACT Numerous chemical constraints have been possible for exoplanetary atmospheres thanks to high-resolution spectroscopy (HRS) from ground-based facilities as well as low-resolution spectroscopy (LRS) from space. These two techniques have complementary strengths, and hence combined HRS and LRS analyses have the potential for more accurate abundance constraints and increased sensitivity to trace species. In this work, we retrieve the atmosphere of the ultra-hot Jupiter WASP-76 b, using high-resolution CARMENES/CAHA (Calar Alto high-Resolution search for M dwarfs with Exoearths with Near-infrared and optical Échelle Spectrographs) and low-resolution Hubble Space Telescope’s (HST) Wide Field Camera 3 (WFC3) and Spitzer observations of the primary eclipse. As such, hot planets are expected to have a substantial fraction of H2O dissociated, we conduct retrievals including both H2O and OH. We explore two retrieval models, one with self-consistent treatment of H2O dissociation and another where H2O and OH are vertically homogeneous. Both models constrain H2O and OH, with H2O primarily detected by LRS and OH through HRS, highlighting the strengths of each technique and demonstrating the need for combined retrievals to fully constrain chemical compositions. We see only a slight preference for the H2O-dissociation model given that the photospheric constraints for both are very similar, indicating $\log (\mathrm{OH/H_2O}) = 0.7^{+0.3}_{-0.3}$ at 1.5 mbar, showing that the majority of the H2O in the photosphere is dissociated. However, the bulk O/H and C/O ratios inferred from the models differs significantly, and highlights the challenge of constraining bulk compositions from photospheric abundances with strong vertical chemical gradients. Further observations with JWST and ground-based facilities may help shed more light on these processes.

Limits on the Detection of an Ultra-short-period Planet in the TOI-539 System

Characterized by their close proximity to their host stars and scorching surface temperatures, hot super-Earths represent a readily accessible population that can be used to study the atmospheres, surfaces, and formation of rocky exoplanets in great detail. We present our radial velocity (RV) data analysis for the star TOI-539, in search of the transiting ultra-short-period hot super-Earth planet candidate TOI-539.01 detected by the Transiting Exoplanet Survey Satellite mission. We constrain the planetary mass of TOI-539.01 at the 2.3σ level. Additionally, we perform injection-recovery tests to determine mass detection limits for potential planets in the RV data set. We suggest an intensive RV campaign with higher precision observations to obtain a precise mass measurement and confirmation of TOI-539.01.

Your journey to Prada Marfa, McDonald Observatory and Santa Elena Canyon: Probes for a hot planet, dark skies and cool gaze

This article takes readers on a brief journey through the remote regions of far west Texas, site of the Greater Big Bend International Dark Sky Reserve, the largest dark sky reserve in the world. Spanning 15,000 square miles, the reserve is home to The University of Texas at Austin McDonald Observatory and Big Bend National Park, along with many other natural areas and art installations. This article uses Prada Marfa, McDonald Observatory and Santa Elena Canyon as probes for a hot planet under dark skies, while also deploying a cool gaze into the Milky Way. In so doing, cool media takes on a profound new meaning for our shared destiny on a tiny planet, getting ever hotter as it hurtles through the vast universe.

Stellar spectral-type (mass) dependence of the dearth of close-in planets around fast-rotating stars

In 2013 a dearth of close-in planets around fast-rotating host stars was found using statistical tests on Kepler data. The addition of more Kepler and Transiting Exoplanet Survey Satellite (TESS) systems in 2022 filled this region of the diagram of stellar rotation period (Prot) versus the planet orbital period (Porb). We revisited the Prot extraction of Kepler planet-host stars, we classify the stars by their spectral type, and we studied their Prot–Porb relations. We only used confirmed exoplanet systems to minimize biases. In order to learn about the physical processes at work, we used the star-planet evolution code ESPEM (French acronym for Evolution of Planetary Systems and Magnetism) to compute a realistic population synthesis of exoplanet systems and compared them with observations. Because ESPEM works with a single planet orbiting around a single main-sequence star, we limit our study to this population of Kepler observed systems filtering out binaries, evolved stars, and multi-planets. We find in both, observations and simulations, the existence of a dearth in close-in planets orbiting around fast-rotating stars, with a dependence on the stellar spectral type (F, G, and K), which is a proxy of the mass in our sample of stars. There is a change in the edge of the dearth as a function of the spectral type (and mass). It moves towards shorter Prot as temperature (and mass) increases, making the dearth look smaller. Realistic formation hypotheses included in the model and the proper treatment of tidal and magnetic migration are enough to qualitatively explain the dearth of hot planets around fast-rotating stars and the uncovered trend with spectral type.

Nitrogen as a Tracer of Giant Planet Formation. II. Comprehensive Study of Nitrogen Photochemistry and Implications for Observing NH3 and HCN in Transmission and Emission Spectra

Atmospheric nitrogen may provide important constraints on giant planet formation. Following our semianalytical work, we further pursue the relation between observable NH3 and an atmosphere’s bulk nitrogen abundance by applying the photochemical kinetics model VULCAN across planetary equilibrium temperature, mass, age, eddy diffusion coefficient, atmospheric composition, and stellar spectral type. We confirm that the quenched NH3 abundance coincides with the bulk nitrogen abundance only at sub-Jupiter-mass (≲1M J) planets and old ages (≳1 Gyr) for solar composition atmospheres, highlighting important caveats for inferring atmospheric nitrogen abundances. Our semianalytical model reproduces the quenched NH3 abundance computed by VULCAN and thus helps to infer the bulk nitrogen abundance from a retrieved NH3 abundance. By computing transmission and emission spectra, we predict that the equilibrium temperature range of 400–1000 K is optimal for detecting NH3 because NH3 depletion by thermochemistry and photochemistry is significant at hotter planets whereas entire spectral features become weak at colder planets. For Jupiter-mass planets around Sun-like stars in this temperature range, NH3 leaves observable signatures of ∼50 ppm at 1.5, 2.1, and 11 μm in transmission spectra and >300–100 ppm at 6 and 11 μm in emission spectra. The photodissociation of NH3 leads HCN to replace NH3 at low pressures. However, the low HCN column densities lead to much weaker absorption features than for NH3. The NH3 features are readily accessible to JWST observations to constrain atmospheric nitrogen abundances, which may open a new avenue to understanding the formation processes of giant exoplanets.

In situ enrichment in heavy elements of hot Jupiters

Context. Radius and mass measurements of short-period giant planets reveal that many of these planets contain a large amount of heavy elements. Although the range of inferred metallicities is broad, planets with more than 100 M⊕ of heavy elements are not rare. This is in sharp contrast with the expectations of the conventional core-accretion model for the origin of giant planets. Aims. The proposed explanations for the heavy-element enrichment of giant planets fall short of explaining the most enriched planets. We look for additional processes that can explain the full envelope of inferred enrichments. Methods. We revisited the dynamics of pebbles and dust in the vicinity of giant planets using analytic estimates and published results on the profile of a gap opened by a giant planet, the radial velocity of the gas with respect to the planet, the Stokes number of particles in the different parts of the disk, and the consequent dust/gas ratio. Although our results are derived in the framework of a viscous α-disk, we also discuss the case of disks driven by angular momentum removal in magnetized winds. Results. When giant planets are far from the star, dust and pebbles are confined to a pressure bump at the outer edge of the planet-induced gap. When the planets reach the inner part of the disk (rp ≪ 2 au), dust instead penetrates into the gap together with the gas. The dust/gas ratio can be enhanced by more than an order of magnitude if the radial drift of dust is not impeded farther out by other barriers. Thus, hot planets undergoing runaway gas accretion can swallow a large amount of dust, acquiring ~100 M⊕ of heavy elements by the time they reach Jupiter masses. Conclusions. Whereas the gas accreted by giant planets in the outer disk is very dust-poor, that accreted by hot planets can be extremely dust-rich. Thus, provided that a large fraction of the atmosphere of hot Jupiters is accreted in situ, a large amount of dust can be accreted as well. We draw a distinction between this process and pebble accretion (i.e., the capture of dust without the accretion of gas), which is ineffective at small stellocentric radii, even for super-Earths. Giant planets farther out in the disk are extremely effective barriers against the flow of pebbles and dust across their gap. Saturn and Jupiter, after locking into a mutual mean motion resonance and reversing their migration, could have accreted small pebble debris.

Hot Earth or Young Venus? A nearby transiting rocky planet mystery

ABSTRACT Venus and Earth provide astonishingly different views of the evolution of a rocky planet, raising the question of why these two rocky worlds evolved so differently. The recently discovered transiting Super-Earth LP 890-9c (TOI-4306c, SPECULOOS-2c) is a key to the question. It circles a nearby M6V star in 8.46 d. LP890-9c receives similar flux as modern Earth, which puts it very close to the inner edge of the Habitable Zone (HZ), where models differ strongly in their prediction of how long rocky planets can hold onto their water. We model the atmosphere of a hot LP890-9c at the inner edge of the HZ, where the planet could sustain several very different environments. The resulting transmission spectra differ considerably between a hot, wet exo-Earth, a steamy planet caught in a runaway greenhouse, and an exo-Venus. Distinguishing these scenarios from the planet’s spectra will provide critical new insights into the evolution of hot terrestrial planets into exo-Venus. Our model and spectra are available online as a tool to plan observations. They show that observing LP890-9c can provide key insights into the evolution of a rocky planet at the inner edge of the HZ as well as the long-term future of Earth.

TESS spots a mini-neptune interior to a hot saturn in the TOI-2000 system

ABSTRACT Hot jupiters (P < 10 d, M > 60 M⊕) are almost always found alone around their stars, but four out of hundreds known have inner companion planets. These rare companions allow us to constrain the hot jupiter’s formation history by ruling out high-eccentricity tidal migration. Less is known about inner companions to hot Saturn-mass planets. We report here the discovery of the TOI-2000 system, which features a hot Saturn-mass planet with a smaller inner companion. The mini-neptune TOI-2000 b (2.70 ± 0.15 R⊕, 11.0 ± 2.4 M⊕) is in a 3.10-d orbit, and the hot saturn TOI-2000 c ($8.14_{-0.30}^{+0.31}$ R⊕ , $81.7_{-4.6}^{+4.7}$ M⊕) is in a 9.13-d orbit. Both planets transit their host star TOI-2000 (TIC 371188886, V = 10.98, TESS magnitude = 10.36), a metal-rich ([Fe/H] = 0.439 $_{-0.043}^{+0.041}$) G dwarf 173 pc away. TESS observed the two planets in sectors 9–11 and 36–38, and we followed up with ground-based photometry, spectroscopy, and speckle imaging. Radial velocities from CHIRON, FEROS, and HARPS allowed us to confirm both planets by direct mass measurement. In addition, we demonstrate constraining planetary and stellar parameters with MIST stellar evolutionary tracks through Hamiltonian Monte Carlo under the PyMC framework, achieving higher sampling efficiency and shorter run time compared to traditional Markov chain Monte Carlo. Having the brightest host star in the V band among similar systems, TOI-2000 b and c are superb candidates for atmospheric characterization by the JWST, which can potentially distinguish whether they formed together or TOI-2000 c swept along material during migration to form TOI-2000 b.

TOI-733 b: A planet in the small-planet radius valley orbiting a Sun-like star

We report the discovery of a hot (Teq ≈ 1055 K) planet in the small-planet radius valley that transits the Sun-like star TOI-733. It was discovered as part of the KESPRINT follow-up program of TESS planets carried out with the HARPS spectrograph. TESS photometry from sectors 9 and 36 yields an orbital period of ${P_{{\rm{orb}}}} = 4.884765_{ - 2.4e - 5}^{ + 1.9e - 5}$ days and a radius of ${R_{\rm{p}}} = 1.992_{ - 0.090}^{ + 0.085}$ R⊕. Multi-dimensional Gaussian process modelling of the radial velocity measurements from HARPS and activity indicators gives a semi-amplitude of K = 2.23 ± 0.26 m s−1, translating into a planet mass of ${M_{\rm{p}}} = 5.72_{ - 0.68}^{ + 0.70}$ M⊕. These parameters imply that the planet is of moderate density (${\rho _{\rm{p}}} = 3.98_{ - 0.66}^{ + 0.77}$ g cm−3) and place it in the transition region between rocky and volatile-rich planets with H/He-dominated envelopes on the mass-radius diagram. Combining these with stellar parameters and abundances, we calculated planet interior and atmosphere models, which in turn suggest that TOI-733 b has a volatile-enriched, most likely secondary outer envelope, and may represent a highly irradiated ocean world. This is one of only a few such planets around G-type stars that are well characterised.

The PEPSI Exoplanet Transit Survey (PETS)

Context. Hot giant planets such as MASCARA-1 b are expected to have thermally inverted atmospheres, which makes them perfect laboratories for atmospheric characterization through high-resolution spectroscopy. Nonetheless, previous attempts at detecting the atmosphere of MASCARA-1 b in transmission have led to negative results. Aims. We aim to detect the optical emission spectrum of MASCARA-1 b. Methods. We used the high-resolution spectrograph PEPSI to observe MASCARA-1 (spectral type A8) near the secondary eclipse of the planet. We cross-correlated the spectra with synthetic templates computed for several atomic and molecular species. Results. We detect Fe I, Cr I, and Ti I in the atmosphere of MASCARA-1 b with a S/N ≈ 7, 4, and 5, respectively, and confirm the expected systemic velocity of ≈13 km s−1 and the radial velocity semi-amplitude of MASCARA-1 b of ≈200 km s−1. The detection of Ti is of particular importance in the context of the recently proposed phenomenon of Ti cold-trapping below a certain planetary equilibrium temperature. Conclusions. We confirm the presence of an atmosphere around MASCARA-1 b through emission spectroscopy. We conclude that the atmospheric non-detection in transmission spectroscopy is due to the strong gravity of the planet and/or to the overlap between the planetary track and its Doppler shadow.

Awesome SOSS: atmospheric characterization of WASP-96 b using the JWST early release observations

ABSTRACT The newly operational JWST offers the potential to study the atmospheres of distant worlds with precision that has not been achieved before. One of the first exoplanets observed by JWST in the summer of 2022 was WASP-96 b, a hot Saturn orbiting a G8 star. As a part of the Early Release Observations programme, one transit of WASP-96 b was observed with NIRISS/SOSS to capture its transmission spectrum from 0.6 to 2.85 μm. In this work, we utilize four retrieval frameworks to report precise and robust measurements of WASP-96 b’s atmospheric composition. We constrain the logarithmic volume mixing ratios of multiple chemical species in its atmosphere, including: H2O = $-3.59 ^{+ 0.35 }_{- 0.35 }$, CO2 = $-4.38 ^{+ 0.47 }_{- 0.57 }$, and K = $-8.04 ^{+ 1.22 }_{- 1.71 }$, thus generally consistent with 1× solar (with the exception of CO2). Notably, our results offer a first abundance constraint on potassium in WASP-96 b’s atmosphere and important inferences on carbon-bearing species such as CO2 and CO. Our short wavelength NIRISS/SOSS data are best explained by the presence of an enhanced Rayleigh scattering slope, despite previous inferences of a clear atmosphere – although we find no evidence for a grey cloud deck. Finally, we explore the data resolution required to appropriately interpret observations using NIRISS/SOSS. We find that our inferences are robust against different binning schemes. That is, from low R = 125 to the native resolution of the instrument, the bulk atmospheric properties of the planet are consistent. Our systematic analysis of these exquisite observations demonstrates the power of NIRISS/SOSS to detect and constrain multiple molecular and atomic species in the atmospheres of hot giant planets.

3D Global climate model of an exo-Venus: a modern Venus-like atmosphere for the nearby super-Earth LP 890-9 c

ABSTRACT The recently discovered super-Earth LP 890-9 c is an intriguing target for atmospheric studies as it transits a nearby, low-activity late-type M-dwarf star at the inner edge of the Habitable Zone. Its position at the runaway greenhouse limit makes it a natural laboratory to study the climate evolution of hot rocky planets. We present the first 3D-Global Climate Model exo-Venus model for a modern Venus-like atmosphere (92 bar surface pressure, realistic composition, and H2SO4 radiatively-active clouds), applied to the tidally-locked LP 890-9 c to inform observations by JWST and future instruments. If LP 890-9 c has developed into a modern exo-Venus, then the modelled temperatures suggest that H2SO4 clouds are possible even in the substellar region. Like on modern Venus, clouds on LP 890-9 c would create a flat spectrum. The strongest CO2 bands in transmission predicted by our model for LP 890-9 c are about 10 ppm, challenging detection, given JWST estimated noise floor. Estimated phase curve amplitudes are 0.9 and 2.4 ppm for continuum and CO2 bands, respectively. While pointing out the challenge to characterise modern exo-Venus analogues, these results provide new insights for JWST proposals and highlight the influence of clouds in the spectrum of hot rocky exoplanet spectra.

Imagining Cooperation: Cold War Aesthetics for a Hot Planet

What does cooperation between rival superpowers look like? Do global issues have the capacity to rise above the geopolitics of the day and trigger alignment between rival powers? This paper argues the Cold War joint space exploration program between the United States and USSR provides a lesson on the limits of cooperation. These limits, I suggest, are not only a matter of power preferences, institutional differences, material disincentives, or even a consequence of a tendency for free-riding. Rather, they are also the result of incompatible “common sense” perceptions. Cooperation, even if institutionally viable, as in the case of the joint space program, can be constrained due to a lack of popular endorsement and legitimacy. To develop the argument, I examine the aesthetics of cooperation rendered through widely circulated media images associated with space cooperation during the Cold War. I argue the Cold War imaginary can serve as both critique and inspiration for today’s attempts to legitimize cooperation on global issues such as climate change. It provides insights on the role of “common sense” perceptions and the ways in which they inform questions concerning universality, the role of affect, and the alure of competition.

The Mantis network

The atmospheres of ultra-hot Jupiters are highly interesting and unique chemical laboratories. Due to the very high atmospheric temperatures, their chemical composition is dominated by atoms and ions instead of molecules, and the formation of aerosols on their day-sides is unlikely. Thus, for these planets detailed chemical characterisations via the direct detection of elements through high-resolution day-side and transit spectroscopy are possible. This in principle allows the element abundances of these objects to be directly inferred, which may provide crucial constraints on their formation process and evolution history. In the recent past, several chemical species, mostly in the form of atoms and ions, have already been detected using high-resolution spectroscopy in combination with the cross-correlation technique. As part of the Mantis network, we provide a grid of standard templates in this study, designed to be used together with the cross-correlation method. This allows for the straightforward detection of chemical species in the atmospheres of hot extrasolar planets. In total, we calculate high-resolution templates for more than 140 different species across several atmospheric temperatures. In addition to the high-resolution templates, we also provide line masks that just include the position of line peaks and their absorption depths relative to the spectral continuum. A separate version of these line masks also takes potential blending effects with lines of other species into account.

Revisiting the Iconic Spitzer Phase Curve of 55 Cancri e: Hotter Dayside, Cooler Nightside, and Smaller Phase Offset

Thermal phase curves of short-period exoplanets provide the best constraints on the atmospheric dynamics and heat transport in their atmospheres. The published Spitzer Space Telescope phase curve of 55 Cancri e, an ultra-short-period super-Earth, exhibits a large phase offset suggesting significant eastward heat recirculation, unexpected on such a hot planet. We present our rereduction and analysis of these iconic observations using the open source and modular Spitzer Phase Curve Analysis pipeline. In particular, we attempt to reproduce the published analysis using the same instrument detrending scheme as the original authors. We retrieve the dayside temperature ( K), nightside temperature ( K at 2σ), and longitudinal offset of the planet's hot spot, and quantify how they depend on the reduction and detrending. Our reanalysis suggests that 55 Cancri e has a negligible hot spot offset of degrees east. The small phase offset and cool nightside are consistent with the poor heat transport expected on ultra-short-period planets. The high dayside 4.5 μm brightness temperature is qualitatively consistent with SiO emission from an inverted rock vapor atmosphere.