Abstract
Stellar obliquity, the angle between a planet’s orbital axis and its host star’s spin axis, traces the formation and evolution of a planetary system. In transiting-exoplanet observations, ...only the sky-projected stellar obliquity can be measured, but this can be deprojected using an estimate of the stellar obliquity. In this paper, we introduce a flexible, hierarchical Bayesian framework that can be used to infer the stellar obliquity distribution solely from sky-projected stellar obliquities, including stellar inclination measurements when available. We demonstrate that while a constraint on the stellar inclination is crucial for measuring the obliquity of an individual system, it is not required for robust determination of the population-level stellar obliquity distribution. In practice, the constraints on the stellar obliquity distribution are mainly driven by the sky-projected stellar obliquities. When applying the framework to all systems with measured sky-projected stellar obliquity, which are mostly hot Jupiter systems, we find that the inferred population-level obliquity distribution is unimodal and peaked at zero degrees. Misaligned systems have nearly isotropic stellar obliquities with no strong clustering near 90°. The diverse range of stellar obliquities prefers dynamic mechanisms, such as planet–planet scattering after a convergent disk migration, which could produce both prograde and retrograde orbits of close-in planets with no strong inclination concentrations other than that at 0°.
Abstract
Transitional disks are protoplanetary disks with large and deep central holes in the gas, possibly carved by young planets. Dong & Dawson simulated systems with multiple giant planets that ...were capable of carving and maintaining such gaps during the disk stage. Here we continue their simulations by evolving the systems for 10 Gyr after disk dissipation and compare the resulting system architecture to observed giant planet properties, such as their orbital eccentricities and resonances. We find that the simulated systems contain a disproportionately large number of circular orbits compared to observed giant exoplanets. Large eccentricities are generated in simulated systems that go unstable, but too few of our systems go unstable, likely due to our demand that they remain stable during the gas-disk stage to maintain cavities. We also explore whether transitional-disk inspired initial conditions can account for the observed younger ages of 2:1 resonant systems orbiting mature host stars. Many simulated planet pairs lock into a 2:1 resonance during the gas-disk stage, but those that are disrupted tend to be disrupted early, within the first 10 Myr. Our results suggest that systems of giant planets capable of carving and maintaining transitional disks are not the direct predecessors of observed giant planets, either because the transitional disk cavities have a different origin or another process is involved, such as convergent migration that packs planets close together at the end of the transitional disk stage.
Abstract
Hot Jupiters may have formed in situ, or been delivered to their observed short periods through one of two categories of migration mechanisms: disk migration or high-eccentricity migration. ...If hot Jupiters were delivered by high-eccentricity migration, we would expect to observe some “super-eccentric” Jupiters in the process of migrating. We update a prediction for the number of super-eccentric Jupiters we would expect to observe in the Kepler sample if all hot Jupiters migrated through high-eccentricity migration and estimate the true number observed by Kepler. We find that the observations fail to match the prediction from high-eccentricity migration with 94.3% confidence and show that high-eccentricity migration can account for at most ∼62% of the hot Jupiters discovered by Kepler.
In this article, we investigate the time-periodic pulse electroosmotic flow (EOF) of Jeffreys fluids through a microannulus. By using the Laplace transform method, the velocity expression of the ...pulse EOF is derived. The effect of some variables on the time it takes for the fluid to go from a static state to a flowing state is analyzed. We find that increasing the relaxation time
and decreasing the inner and outer radius ratio
will result in longer time for the fluid to reach the flowing state, but the retardation time
and the inner and outer zeta potential ratio
have little effect on it. The impact of some related parameters on the pulse EOF velocity for different inner and outer radius ratios (
) is discussed in detail. The results show that for a smaller inner and outer radius ratio
, the velocity amplitude increases with the relaxation time
and decreases with the retardation time
. As the inner and outer radius ratio
increases, the effect of relaxation time
on velocity amplitude gradually weakens or even becomes insignificant, and the effect of the retardation time
on the velocity amplitude remains unchanged. Moreover, the velocity amplitude will decrease with the increase in the inner and outer radius ratio
and its change range will expand from the electric double layer near the annular wall to the entire flow region.
We report the discovery of TOI-4127 b, which is a transiting, Jupiter-sized exoplanet on a long period (P=56.39879 +0.00010-0.00010days) and a high-eccentricity orbit around a late F-type dwarf star. ...This warm Jupiter was first detected and identified as a promising candidate from a search for single-transit signals in TESS Sector 20 data and was later characterized as a planet following two subsequent transits (TESS Sectors 26 and 53) and follow-up ground-based RV observations with the NEID and SOPHIE spectrographs. We jointly fit the transit and RV data to constrain the physical (Rp=1.096+0.039-0.032RJ, Mp=2.30+0.11-0.11MJ) and orbital parameters of the exoplanet. Given its high orbital eccentricity (𝓮=0.7471+0.0078-0.0086), TOI-4127 b is a compelling candidate for studies of warm Jupiter populations and of hot Jupiter formation pathways. We show that the present periastron separation of TOI-4127 b is too large for high-eccentricity tidal migration to circularize its orbit, and that TOI-4127 b is unlikely to be a hot Jupiter progenitor unless it is undergoing angular momentum exchange with an undetected outer companion. Although we find no evidence for an external companion, the available observational data are insufficient to rule out the presence of a perturber that can excite eccentricity oscillations and facilitate tidal migration.
We confirm the planetary nature of TOI-1728b using a combination of ground-based photometry, near-infrared Doppler velocimetry and spectroscopy with the Habitable-zone Planet Finder. TOI-1728 is an ...old, inactive M0 star with Teff = K, which hosts a transiting super-Neptune at an orbital period of ∼3.49 days. Joint fitting of the radial velocities and TESS and ground-based transits yields a planetary radius of R⊕, mass M⊕, and eccentricity . We estimate the stellar properties, and perform a search for He 10830 absorption during the transit of this planet and claim a null detection with an upper limit of 1.1% with 90% confidence. A deeper level of He 10830 absorption has been detected in the planet atmosphere of GJ 3470b, a comparable gaseous planet. TOI-1728b is the largest super-Neptune-the intermediate subclass of planets between Neptune and the more massive gas-giant planets-discovered around an M dwarf. With its relatively large mass and radius, TOI-1728 represents a valuable data point in the M-dwarf exoplanet mass-radius diagram, bridging the gap between the lighter Neptune-sized planets and the heavier Jovian planets known to orbit M dwarfs. With a low bulk density of g cm−3, and orbiting a bright host star (J ∼ 9.6, V ∼ 12.4), TOI-1728b is also a promising candidate for transmission spectroscopy both from the ground and from space, which can be used to constrain planet formation and evolutionary models.
Abstract
We present the first exoplanet phase-curve measurement made with the JWST NIRSpec instrument, highlighting the exceptional stability of this newly commissioned observatory for exoplanet ...climate studies. The target, WASP-121b, is an ultrahot Jupiter with an orbital period of 30.6 hr. We analyze two broadband light curves generated for the NRS1 and NRS2 detectors, covering wavelength ranges of 2.70–3.72
μ
m and 3.82–5.15
μ
m, respectively. Both light curves exhibit minimal systematics, with approximately linear drifts in the baseline flux level of 30 ppm hr
−1
(NRS1) and 10 ppm hr
−1
(NRS2). Assuming a simple brightness map for the planet described by a low-order spherical harmonic dipole, our light-curve fits suggest that the phase curve peaks coincide with orbital phases 3.°36 ± 0.°11 (NRS1) and 2.°66 ± 0.°12 (NRS2) prior to mideclipse. This is consistent with the strongest dayside emission emanating from eastward of the substellar point. We measure planet-to-star emission ratios of 3924 ± 7 ppm (NRS1) and 4924 ± 9 ppm (NRS2) for the dayside hemisphere and 136 ± 8 ppm (NRS1) and 630 ± 10 ppm (NRS2) for the nightside hemisphere. The latter nightside emission ratios translate to planetary brightness temperatures of 926 ± 12 K (NRS1) and 1122 ± 10 K (NRS2), which are low enough for a wide range of refractory condensates to form, including enstatite and forsterite. A nightside cloud deck may be blocking emission from deeper, hotter layers of the atmosphere, potentially helping to explain why cloud-free 3D general circulation model simulations systematically overpredict the nightside emission for WASP-121b.
Purpose Ovarian cancer (OC) is characterized by a high recurrence rate, and homologous recombination deficiency (HRD) is an important biomarker in the clinical management of OC. We investigated the ...differences in clinical genomic profiles between the primary and platinum-sensitive recurrent OC (PSROC), focusing on HRD status. Materials and methods A total of 40 formalin-fixed paraffin-embedded (FFPE) tissues of primary tumors and their first platinum-sensitive recurrence from 20 OC patients were collected, and comprehensive genomic profiling (CGP) analysis of FoundationOne.sup.RCDx (F1CDx) was applied to explore the genetic (dis)similarities of the primary and recurrent tumors. Results By comparing between paired samples, we found that genomic loss of heterozygosity (gLOH) score had a high intra-patient correlation (r.sup.2 = 0.79) and that short variants (including TP53, BRCA1/2 and NOTCH1 mutations), tumor mutational burden (TMB) and microsatellite stability status remained stable. The frequency of (likely) pathological BRCA1/2 mutations was 30% (12/40) in all samples positively correlated with gLOH scores, but the proportion of gLOH-high status (score > 16%) was 50% (10/20) and 55% (11/20) in the primary and recurrent samples, respectively. An additional 20% (4/20) of patients needed attention, a quarter of which carried the pathological BRCA1 mutation but had a gLOH-low status (gLOH < 16%), and three-quarters had different gLOH status in primary-recurrent pairs. Furthermore, we observed the PSROC samples had higher gLOH scores (16.1 + or - 9.24 vs. 19.4 + or - 11.1, p = 0.007), more CNVs (36.1% vs. 15.1% of discordant genomic alternations), and significant enrichment of altered genes in TGF-beta signaling and Hippo signaling pathways (p < 0.05 for all) than their paired primaries. Lastly, mutational signature and oncodrive gene analyses showed that the computed mutational signature similarity in the primary and recurrent tumors were best matched the COSMI 3 signature (Aetiology of HRD) and had consistent candidate cancer driver genes of MSH2, NOTCH1 and MSH6. Conclusion The high genetic concordance of the short variants remains stable along OC recurrence. However, the results reveal significantly higher gLOH scores in the recurrent setting than in paired primaries, supporting further clinically instantaneity HRD assay strategy. Keywords: Ovarian cancer, Homologous recombination deficiency (HRD), Genomic loss of heterozygosity (gLOH), Comprehensive genomic profiling (CGP)
Abstract
We report the measurement of the sky-projected obliquity angle
λ
of the warm Jovian exoplanet TOI-1670 c via the Rossiter–McLaughlin effect. We observed the transit window during UT 2023 ...April 20 for 7 continuous hours with NEID on the 3.5 m WIYN Telescope at Kitt Peak National Observatory. TOI-1670 hosts a sub-Neptune (
P
∼ 11 days; planet b) interior to the warm Jovian (
P
∼ 40 days; planet c), which presents an opportunity to investigate the dynamics of a warm Jupiter with an inner companion. Additionally, TOI-1670 c is now among the longest-period planets to date to have its sky-projected obliquity angle measured. We find planet c is well aligned to the host star, with
λ
= − 0.°3 ± 2.°2. TOI-1670 c joins a growing census of aligned warm Jupiters around single stars and aligned planets in multiplanet systems.
TOI-2076 b is a sub-Neptune-sized planet (R = 2.39 ± 0.10 Rꚛ) that transits a young (204 ± 50 MYr) bright (V = 9.2) K-dwarf hosting a system of three transiting planets. Using spectroscopic ...observations obtained with the NEID spectrograph on the WIYN 3.5 m Telescope, we model the Rossiter–McLaughlin effect of TOI-2076 b, and derive a sky-projected obliquity of λ = -3 +16o −15 . Using the size of the star (R = 0.775 ± 0.015 Re), and the stellar rotation period (Prot = 7.27 ± 0.23 days), we estimate an obliquity of 𝜓=18 +10o −9 (𝜓 < 34° at 95% confidence), demonstrating that TOI-2076 b is in a well-aligned orbit. Simultaneous diffuser-assisted photometry from the 3.5 m telescope at Apache Point Observatory rules out flares during the transit. TOI-2076 b joins a small but growing sample of young planets in compact multi-planet systems with well-aligned orbits, and is the fourth planet with an age ≲300 Myr in a multi-transiting system with an obliquity measurement. The low obliquity of TOI-2076 b and the presence of transit timing variations in the system suggest the TOI-2076 system likely formed via convergent disk migration in an initially well-aligned disk.
PDF
