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Abstract High-eccentricity gas giant planets serve as unique laboratories for studying the thermal and chemical properties of H/He-dominated atmospheres. One of the most extreme cases is HD 80606 b—a hot Jupiter orbiting a Sun-like star with an eccentricity of 0.93—which experiences an increase in incident flux of nearly 3 orders of magnitude as the star–planet separation decreases from 0.88 au at apoastron to 0.03 au at periastron. We observed the planet’s periastron passage using JWST’s NIRSpec/G395H instrument (2.8–5.2μm) during a 21 hr window centered on the eclipse. We find that, as the planet passes through periastron, its emission spectrum transitions from a featureless blackbody to one in which CO, CH₄, and H₂O absorption features are visible. We detect CH₄during postperiapse phases at 4.1–10.7σdepending on the phase and on whether a flux offset is included to account for NRS1 detector systematics. Following periapse, H₂O and CO are also detected at 4.2–5.5σand 3.7–4.4σ, respectively. Furthermore, we rule out the presence of a strong temperature inversion near the IR photosphere based on the lack of obvious emission features throughout the observing window. General circulation models had predicted an inversion during periapse passage. Our study demonstrates the feasibility of studying hot Jupiter atmospheres using partial phase curves obtained with NIRSpec/G395H. 

Abstract We report the discovery of two directly imaged, giant planet candidates orbiting the metal-rich, hydrogen atmosphere white dwarfs WD 1202−232 and WD 2105−82. JWST’s Mid-Infrared Instrument (MIRI) data on these two stars show a nearby resolved source at a projected separation of 11.47 and 34.62 au, respectively. Assuming the planets formed at the same time as their host stars, with total ages of 5.3 and 1.6 Gyr, the MIRI photometry is consistent with giant planets with masses ≈1–7M_Jup. The probability of both candidates being false positives due to red background sources is approximately 1 in 3000. If confirmed, these would be the first directly imaged planets that are similar in both age and separation to the giant planets in our own solar system, and they would demonstrate that widely separated giant planets like Jupiter survive stellar evolution. Giant planet perturbers are widely used to explain the tidal disruption of asteroids around metal-polluted white dwarfs. Confirmation of these two planet candidates with future MIRI imaging would provide evidence that directly links giant planets to metal pollution in white dwarf stars. 

Abstract The Transiting Exoplanet Survey Satellite (TESS) has surveyed nearly the entire sky in full-frame image mode with a time resolution of 200 s to 30 minutes and a temporal baseline of at least 27 days. In addition to the primary goal of discovering new exoplanets, TESS is exceptionally capable at detecting variable stars, and in particular short-period eclipsing binaries, which are relatively common, making up a few percent of all stars, and represent powerful astrophysical laboratories for deep investigations of stellar formation and evolution. We combed Sectors 1–82 of the TESS full-frame image data searching for eclipsing binary stars using a neural network that identified ∼1.2 million stars with eclipse-like features. Of these, we have performed an in-depth analysis on ∼60,000 targets using automated methods and manual inspection by citizen scientists. Here we present a catalog of 10,001 uniformly vetted and validated eclipsing binary stars that passed all our ephemeris and photocenter tests, as well as complementary visual inspection. Of these, 7936 are new eclipsing binaries while the remaining 2065 are known systems for which we update the published ephemerides. We outline the detection and analysis of the targets, discuss the properties of the sample, and highlight potentially interesting systems. Finally, we also provide a list of ∼900,000 unvetted and unvalidated targets for which the neural network found eclipse-like features with a score higher than 0.9, and for which there are no known eclipsing binaries within a sky-projected separation of a TESS pixel (≈21″). 

Abstract The launch of JWST has ushered in a new era of high-precision infrared astronomy, allowing us to probe nearby white dwarfs for cold dust, exoplanets, and tidally heated exomoons. While previous searches for these exoplanets have successfully ruled out companions as small as 7–10 Jupiter masses (M_Jup), no instrument prior to JWST has been sensitive to the likely more common sub-Jovian-mass planets around white dwarfs. In this paper, we present the first multiband photometry (F560W, F770W, F1500W, F2100W) taken of WD 2149+021 with the Mid-Infrared Instrument on JWST. After a careful search for both resolved and unresolved planets, we do not identify any compelling candidates around WD 2149+021. Our analysis indicates that we are sensitive to companions as small as ∼0.5M_Jupoutwards of 1.″263 (28.3 au) and ∼1.0M_Jupat the innermost working angle (0.″654, 14.7 au) at 3 Gyr with 5σconfidence, placing significant constraints on any undetected companions around this white dwarf. The results of these observations emphasize the exciting future of sub-Jovian planet detection limits by JWST, which can begin to constrain how often these planets survive their host stars' evolution. 

We report the discovery of TOI-4641b, a warm Jupiter transiting a rapidly rotating F-type star with a stellar effective temperature of 6560 K. The planet has a radius of 0.73 RJup, a mass smaller than 3.87 MJup(3σ), and a period of 22.09 d. It is orbiting a bright star (V=7.5 mag) on a circular orbit with a radius and mass of 1.73 R⊙ and 1.41 M⊙. Follow-up ground-based photometry was obtained using the Tierras Observatory. Two transits were also observed with the Tillinghast Reflector Echelle Spectrograph, revealing the star to have a low projected spin-orbit angle (λ=$$1.41^{+0.76}_{-0.76}$$°). Such obliquity measurements for stars with warm Jupiters are relatively few, and may shed light on the formation of warm Jupiters. Among the known planets orbiting hot and rapidly rotating stars, TOI-4641b is one of the longest period planets to be thoroughly characterized. Unlike hot Jupiters around hot stars which are more often misaligned, the warm Jupiter TOI-4641b is found in a well-aligned orbit. Future exploration of this parameter space can add one more dimension to the star–planet orbital obliquity distribution that has been well sampled for hot Jupiters. 

Abstract Exoplanet discoveries have revealed a dramatic diversity of planet sizes across a vast array of orbital architectures. Sub-Neptunes are of particular interest; due to their absence in our own solar system, we rely on demographics of exoplanets to better understand their bulk composition and formation scenarios. Here, we present the discovery and characterization of TOI-1437 b, a sub-Neptune with a 18.84 day orbit around a near-solar analog (M_⋆= 1.10 ± 0.10M_☉,R_⋆=1.17 ± 0.12R_☉). The planet was detected using photometric data from the Transiting Exoplanet Survey Satellite (TESS) mission and radial velocity (RV) follow-up observations were carried out as a part of the TESS-Keck Survey using both the HIRES instrument at Keck Observatory and the Levy Spectrograph on the Automated Planet Finder telescope. A combined analysis of these data reveal a planet radius ofR_p= 2.24 ± 0.23R_⊕and a mass measurement ofM_p= 9.6 ± 3.9M_⊕). TOI-1437 b is one of few (∼50) known transiting sub-Neptunes orbiting a solar-mass star that has a RV mass measurement. As the formation pathway of these worlds remains an unanswered question, the precise mass characterization of TOI-1437 b may provide further insight into this class of planet. 

Abstract GRB 221009A ( z = 0.151) is one of the closest known long γ -ray bursts (GRBs). Its extreme brightness across all electromagnetic wavelengths provides an unprecedented opportunity to study a member of this still-mysterious class of transients in exquisite detail. We present multiwavelength observations of this extraordinary event, spanning 15 orders of magnitude in photon energy from radio to γ -rays. We find that the data can be partially explained by a forward shock (FS) from a highly collimated relativistic jet interacting with a low-density, wind-like medium. Under this model, the jet’s beaming-corrected kinetic energy ( E K ∼ 4 × 10 50 erg) is typical for the GRB population. The radio and millimeter data provide strong limiting constraints on the FS model, but require the presence of an additional emission component. From equipartition arguments, we find that the radio emission is likely produced by a small amount of mass (≲6 × 10 −7 M ⊙ ) moving relativistically (Γ ≳ 9) with a large kinetic energy (≳10 49 erg). However, the temporal evolution of this component does not follow prescriptions for synchrotron radiation from a single power-law distribution of electrons (e.g., in a reverse shock or two-component jet), or a thermal-electron population, perhaps suggesting that one of the standard assumptions of afterglow theory is violated. GRB 221009A will likely remain detectable with radio telescopes for years to come, providing a valuable opportunity to track the full lifecycle of a powerful relativistic jet. 

Abstract The mergers of binary compact objects such as neutron stars and black holes are of central interest to several areas of astrophysics, including as the progenitors of gamma-ray bursts (GRBs)¹, sources of high-frequency gravitational waves (GWs)²and likely production sites for heavy-element nucleosynthesis by means of rapid neutron capture (ther-process)³. Here we present observations of the exceptionally bright GRB 230307A. We show that GRB 230307A belongs to the class of long-duration GRBs associated with compact object mergers^4–6and contains a kilonova similar to AT2017gfo, associated with the GW merger GW170817 (refs. ^7–12). We obtained James Webb Space Telescope (JWST) mid-infrared imaging and spectroscopy 29 and 61 days after the burst. The spectroscopy shows an emission line at 2.15 microns, which we interpret as tellurium (atomic massA = 130) and a very red source, emitting most of its light in the mid-infrared owing to the production of lanthanides. These observations demonstrate that nucleosynthesis in GRBs can creater-process elements across a broad atomic mass range and play a central role in heavy-element nucleosynthesis across the Universe.