raptop (π’€― π’„· π’„ˆπ’€­π’‡)17h ago
So, uh, 6 recent #exoplanet arχiv papers that I thought were neat and would encourage people to check out:
Characterizing the atmospheres of 5 hot Jupiters with JWST (1 is completely featureless, so probably cloudy): https://arxiv.org/abs/2603.21273
High-resolution spectroscopic atmospheric studies of 5 hot Jupiters across the edge of the Neptune desert

Hot Jupiters (HJs), especially the Ultra-Hot Jupiters (UHJs), are ideal targets for robust atmospheric characterization, thanks to their high equilibrium temperatures and large atmospheric scale heights, which result from their proximity to their host stars and intense stellar irradiation. Here, we present atmospheric studies of five planets, namely WASP-50b, WASP-117b, WASP-156b, WASP-167b, and WASP-173Ab. These five planets include two UHJs, two classic HJs, and one hot Neptune, with four of them just on the upper and middle borders of the Neptune desert, providing an interesting sample for investigating the connection between planetary atmospheric composition and bulk properties. We have not detected any significant absorption signals exceeding 3$Οƒ$ in the three less-inflated, relatively high-density HJs (WASP-50b, WASP-156b, and WASP-173Ab). We marginally detect H$Ξ±$ and Li I with 3.2$Οƒ$ and 3.1$Οƒ$ in WASP-117b, respectively. In WASP-167b, we report tentative detection of H$Ξ±$ and Fe I at 4.6$Οƒ$ and $\sim3.4Οƒ$, receptively. In addition, Fe I is significantly detected with a max SNR of 7.3 $Οƒ$ using the cross-correlation technique, which exhibits a blue-shifted signal. For WASP-167b, we perform an atmospheric retrieval and yield the abundances of Fe, Mg, Ca, Ti, V, and equilibrium temperature of ${2479^{+193}_{-174}}$K. Comparing WASP-173Ab and WASP-167b, both are UHJ, but with quite different extents of atmospheric signals, we propose that there may be a transition in $T_{\rm eq}$ between 1900 and 2300K.

arXiv.org
Show threadraptop (π’€― π’„· π’„ˆπ’€­π’‡)17h ago
A large sample of Kepler planets suggests that while ones around binary systems exhibit β€œpeas-in-a-pod” architectures in terms of planet sizes, like around single ones, the systems tend to have more single planets (as opposed to 2+), and what multiple planet systems are found are more compact (and with 3+ a more complex gap spacing): https://arxiv.org/abs/2603.21897
Planetary Architectures of Kepler Compact Multis with Binary Star Companions

Planets in binary-star systems exhibit demographic differences compared to planets in single-star systems. In particular, planets with binary-star hosts have a lower overall occurrence rate compared to their single-star counterparts, as well as a suppressed relative occurrence rate for sub-Neptunes ($R_p=2{-}4R_{\oplus}$) compared to super-Earths ($R_p=1.0{-}1.5R_{\oplus}$). These differences are most pronounced in close separation binaries ($ρ< 100$ au) which has been interpreted as a result of binary stars disrupting the protoplanetary disks of their stellar companions. The architectures of planetary systems -- i.e. the arrangements of planet sizes and orbits -- provide additional information about system formation and evolution. Architectures of single-star planetary systems are well studied, but architectures of binary-star planetary systems have not been investigated in detail. In this work, we analyzed a large sample of Kepler planetary systems (162 planets in 118 binary-star systems; 880 planets in 544 single-star systems) to compare their architectures as a function of stellar multiplicity. We found that planets with binary-star hosts follow a similar ``peas-in-a-pod'' tendency toward uniformity in planet radii and log-uniformity in period spacing as planets with single-star hosts. However, we also detected modest ($2.5-3Οƒ$) differences in period spacing and planet multiplicity, with binary-star systems having higher typical gap complexities (indicating more uneven spacing) and a higher prevalence of single planets. We interpret these results as evidence that binary stars primarily influence the planetary architectures of their stellar companions by shaping the protoplanetary disk at formation, with subsequent dynamical processing more gently altering the system architectures over secular timescales.

arXiv.org
Show threadraptop (π’€― π’„· π’„ˆπ’€­π’‡)17h ago
We’re slowly characterizing the radius valley along different axes (eg: metallicity, stellar activity, C/O ratios), though there’s still a lot unknown. Also core-powered mass loss matters, not just stellar irradiation: https://arxiv.org/abs/2603.21581
Insights into the Exoplanet Radius Valley from Host-Star Ages, Activity, Chemistry, and Birth Radius

The radius valley, a bimodal feature in the size distribution of close-in small exoplanets, is widely interpreted as a signature of atmospheric loss and therefore provides a key constraint on the formation and atmospheric evolution of these planets. We investigate its dependence on host-star properties using 769 planets orbiting 558 stars, for which we derive stellar ages, chromospheric activity, and Galactic birth radius, together with elemental abundances. We find that the radius valley is not fully established at ages $\sim 3$ Gyr and evolves over gigayear timescales, with its prominence strongly affected by stellar population mixing. The dependence on magnetic activity is non-monotonic: a clear valley is present even among magnetically quiet stars, while highly active systems do not show a systematically stronger depletion. The valley morphology also varies with stellar composition: the valley is strongest in metal-poor stars, weakens near solar metallicity, and partially strengthens again at the highest metallicities. In addition, the valley shows sensitivity to refractory element ratios such as [Mg/Si], while correlations with [C/O] are weaker, indicating a dependence on planetary interior structure. Our results are more consistent with a dominant role for core-powered atmospheric mass loss than with purely irradiation-driven photoevaporation. Finally, the radius valley also depends on the Galactic birth environment, with systems near the estimated solar birth radius $\sim 4.5$ kpc showing a high fraction of Earth-like planets and a well-defined bimodal structure, suggesting that the Solar System formed in a region with a well-developed Earth-sized planet population.

arXiv.org
Show threadraptop (π’€― π’„· π’„ˆπ’€­π’‡)

Another day, another code. But this one looks to have found 100 planets in TESS data and points to 2000 more good candidates! The uniform bit also suggests that this will give a population good for characterization and demographics studies: https://arxiv.org/abs/2603.22597

(also, πŸ¦β€β¬›)

Automatic search for transiting planets in TESS-SPOC FFIs with RAVEN: over 100 newly validated planets and over 2000 vetted candidates

Space-based missions such as TESS are identifying a wealth of short-period ($\lesssim30$ d) transiting planets. Despite the growing number of confirmed and candidate planets, the sample is still incomplete and highly biased, challenging demographic studies. Moreover, there are still a large number of unconfirmed candidates that can end up being false positives. We use the new pipeline RAVEN to perform a uniform search and validation of transiting planet candidates in TESS data. We focus on a magnitude-limited sample of over 2.2 million main sequence stars well characterised by Gaia and observed by TESS in its Full Frame Images during its first 4 years of operations (sectors 1 to 55). We aim to detect candidates with periods within $0.5-16$ days. RAVEN detects candidates with a box least squares algorithm, classifies them into transiting planets and false positives using machine learning models trained with realistic simulations, and performs statistical validation. We present several samples of candidates with different levels of vetting and validation. We newly validate 118 planets, including 31 newly detected here. We also present a sample of over 2000 candidates not validated but with high probability of being planets, including $\sim1000$ new candidates, a small sample of newly identified mono- and duo-transiting candidates, and a sample of large radii ($>8~\mathrm{R_{\oplus}}$) candidates with high planet probability suited for further follow-up. Our samples of vetted and validated transiting planet candidates represent a major effort towards improving the candidate sample from TESS.

arXiv.org
Mar 25 at 10:03pmWeb
Show threadraptop (π’€― π’„· π’„ˆπ’€­π’‡)17h ago
Finally, hot Jupiter formation (well, okay also warm and cold Jupiters as well) is becoming understood, including the orbital inclination and eccentricity distributions of the various populations. So it’s mostly planet-planet scattering (with warm Jupiters mostly forming in place but getting perturbed orbits?). There are a lot of other details of the population features that won’t fit in a toot: https://arxiv.org/abs/2603.22409 https://arxiv.org/abs/2603.22426
Unified Formation Channel of Hot and Warm Jupiters via Planet-Planet Scattering

Recent observations show distinct orbital architectures for hot and warm Jupiters: hot Jupiters span a wide range of stellar obliquities and tend to host distant companions without close-by companions, whereas warm Jupiters are often aligned and accompanied by both close-by and distant companions. In this paper, we revisit planet-planet scattering and demonstrate that it provides a unified framework for both populations. Using N-body simulations with tides, we explore three regimes: hot (a_1 < 0.1 AU), warm (0.1 < a_1 < 1 AU), and cold (1 < a_1 < 10 AU) scattering. Hot scattering predominantly produces compact hot-Jupiter pairs, which are rarely observed, implying this channel is rare. Cold scattering readily produces retrograde hot Jupiters and likely constitutes a main reservoir feeding the hot-Jupiter population. However, cold scattering produces few inner warm Jupiters at a at about 0.1-0.3 AU. We show that warm scattering naturally fills this gap: high-inclination inner warm Jupiters produced by warm scattering are preferentially removed through further eccentricity excitation followed by tidal circularization into hot Jupiters. As a result, the surviving inner warm Jupiters are biased toward a broad range of eccentricities but modest inclinations, producing the observed "eccentric-but-aligned" population. This story makes testable predictions: (i) warm Jupiters, especially at a >~ 0.3 AU, should not be exclusively aligned, and (ii) warm Jupiters should often host nearby companions with non-negligible mutual inclinations up to <~ 30 degrees.

arXiv.org
Show threadraptop (π’€― π’„· π’„ˆπ’€­π’‡)16h ago
Oh, and πŸ”ͺ πŸ”ͺ πŸ”ͺ the popular articles calling this "AI detects 100 TESS planets"