ABSTRACT The formation of tight stellar binaries remains an unsolved problem. There is too much angular momentum in a collapsing and fragmenting protostellar cloud to form a stellar binary in situ with a separation less than an AU, yet thousands of these short-period binaries have been discovered. One indication of a binary’s formation is the angle between the stellar spin and orbital axes – its obliquity. The classical method for determining projected stellar obliquities is the Rossiter–McLaughlin effect. This has been applied to 132 hot Jupiters, but only a handful of stellar binaries. Of the binary systems with measured projected obliquities, even fewer have measured 3D obliquities. In this paper, we add five more short-period binary 3D obliquity measurements to the sample previously consisting of one system. We present Rossiter–McLaughlin measurements for EBLM J0239-20, EBLM J0941-31, EBLM J1037-25, EBLM J1141-37, and EBLM J2025-45. These systems consist of an M-dwarf eclipsing an F/G-type primary. We combine CORALIE and HARPS spectroscopy with TESS photometry of primary and secondary eclipses. We show that even though the sky-projected obliquities seem to be aligned, there is modest but non-zero spin-orbit misalignment ($\psi$ between 5 and 20$^{\circ }$). Our primary stars straddle the Kraft break at $\sim 6250$ K. We derive the M-dwarf masses and radii to precisions better than 3 per cent. With the exception of EBLM J0941-31, each system has an inflated radius, exceeding stellar model predictions by more than 5$\sigma$.

We identify two large-radius planets around the F-type star HD 114082 as the longest-period young transiting exoplanets known. From the first transit, detected by NASA's Transiting Exoplanet Survey Satellite (TESS), and a second dip, spotted by the Next-Generation Transit Survey (NGTS), we predicted midtransit times for HD 114082 b (planet b). We pinpoint its orbit (period P-b = 225.5504 +/- 0.0004 days) from a third transit captured with the ESA's CHaracterising ExOplanet Satellite and the upgraded Antarctic Search for Transiting ExoPlanets telescope (ASTEP+), alongside orbit-discriminating observations. Another dimming partly covered by ASTEP+ completes the four-transit series. We support with dynamical evidence the planetary nature of a deeper transit detected with TESS and NGTS, identifying planet c. Additionally, we reexamine the debris disk, fitting its excess emission with two dust components. Fundamental stellar parameters are inferred from stellar evolution models, while a joint modeling of photometric and radial velocity time series yields the planetary parameters, with masses further constrained using an N-body code. For planet b, the semimajor axis a(b) = 0.791 +/- 0.008 au, eccentricity e(b) approximate to 0, inclination i(b) = 89 . degrees 791 +/- 0.014, radius R-b = 1.046 +/- 0.014 R-J, and 95% confidence upper limit on its mass M-95%,M-b = 1.6 M-J. For planet c, a(c) = 0.99 - 0.04 + 0.03 au, e(c) approximate to 0, i(c) = 89 . degrees 701 +/- 0.011, R-c = 1.36 +/- 0.03 R-J, and M-95%,M-c = 2.0 M-J (0.24 M-J if adding transit-timing-variation constraints). They seem to be moderate-to-low-mass giants in nearly resonant, coplanar, circular orbits that formed in situ, or beyond the snow line, and migrated inward, shaping the disk.

The Neptunian desert is a distinct lack of Neptune-sized planets at short orbital periods, purportedly carved by photoevaporation and tidal circularisation following high-eccentricity migration. Constraining these processes and how they vary across different hoststar spectral types requires detailed characterisation of the planets in the desert and around its boundaries. In this study, we confirm the planetary nature of a massive super-Neptune identified by TESS around the M0 dwarf TOI-672. We analysed photometry from TESS and ExTrA and precise radial velocity measurements taken with the recently commissioned Near-InfraRed Planet Searcher (NIRPS) and HARPS spectrographs. We measured a planetary orbital period of 3.634 days, a radius of 5.31−0.26+0.24 R⊕, and mass of 50.9−4.4+4.5 M⊕. Our findings place TOI-672 b within the Neptunian ridge, a pile-up of planets from 3-5 days at the Neptunian desert boundary. We used a novel approach to determine the desert boundaries in period-radius space and instellation-radius space, and for the first time, we compared the Neptunian desert boundaries for planets orbiting FGK versus M dwarf stars. We determined that the boundary ridge shifts slightly inwards from 3.3 ± 1.4 days for FGK host stars to 2.2 ± 1.0 days for M dwarf host stars. Statistically, these values do not significantly differ from each other, and the shift to shorter periods for M dwarf planets is smaller than what theoretical photoevaporation models predict. We also find that TOI-672 b is a single-planet system within the sensitivity limits of our RV and TTV datasets.

The PLATO mission is scheduled for launch early 2027. In this paper we present an overview of the performance drivers for the mission at the time where all flight models of the cameras have been tested and integrated on the optical bench. The PLATO consortium needs an estimate of the planet detection yield to dimension the ground-based radial velocity follow-up resources. We provide updated estimates on the yield of planet detections that can be expected from the mission under certain assumptions. As of today, large uncertainties remain on the planet occurrence rates, especially for small planets in long-period orbits, and on our ability to detect these planets in the presence of stellar variability and instrumental noise. To partially overcome these limitations, we compare results using different planet occurrence rates, detectability rates, and we include an estimate on the expected contribution of stellar variability to the noise budget. The final detection yield of PLATO will provide constraints to planet occurrence rates which in turn will help constraining planet formation models.

The radii of small exoplanets form two populations, super-Earths and sub-Neptunes, separated by a gap known as the radius valley. This feature could be produced by the removal of atmospheres by stellar or internal heating or by the lack of an initial envelope. We used transit photometry and radial velocity measurements to detect and characterize four exoplanets orbiting LHS 1903, a red dwarf star in the Milky Way's thick disk. These four planets have orbital periods ranging from 2.2 to 29.3 days and span the radius valley within a single planetary system. The derived densities indicate that LHS 1903 b is rocky, whereas LHS 1903 c and LHS 1903 d have extended atmospheres. The most distant planet from the host star, LHS 1903 e, has no gaseous envelope, indicating that it formed from gas-depleted material.

We report the discovery and characterisation of NGTS-39 b (TIC 453147896 b), a warm Jupiter transiting a Sun-like star on a 58.2 day, eccentric (e = 0.386 +/- 0.019) orbit. NGTS-39 b was first identified from a TESS single-transit event, and subsequently confirmed with NGTS photometry and radial-velocity measurements from CORALIE and HARPS. The host star is a bright (Tmag = 11.02) F9 dwarf with an effective temperature of Teff = 6053 +67/-30 K. NGTS-39 b is a Jupiter-sized gas giant with a radius of 1.088 +/- 0.012 RJ and a mass of 1.467 +/- 0.081 MJ. Its equilibrium temperature is 519 +6/-5 K, placing it between short-period hot Jupiters and cold, Jupiter-like giants. The high orbital eccentricity and intermediate equilibrium temperature of NGTS-39 b make it a valuable test case for formation and migration models, particularly in the poorly sampled regime of long-period gas giants. The RV data show a linear trend of gamma dot = -17.75 m s^-1 yr^-1, which indicates the presence of an outer companion. The discovery of NGTS-39 b contributes to the small but growing population of transiting warm Jupiters with P > 50 days orbiting bright stars.

In order to meet the science goals of the PLATO space mission, an extensive science calibration and validation plan has been designed. This paper describes this plan, as well as the methodology adopted to select the science calibration and validation stars that have entered its input catalogue. This is the so-called scvPIC, which is part of the general PLATO Input Catalogue (PIC) for the first selected long pointing field in the Southern Hemisphere known as LOPS2. While many of PLATO's science requirements needed dedicated stars as calibrators as discussed here, its most stringent requirement is the delivery of the age of the host stars of exoplanetary systems with an accuracy better than 10% for a G0V star of V = 10 mag, i.e. a nearby Sun-like star. This is presently not within reach for large populations of dwarfs and subgiants in the Milky Way as it requires the models of their stellar interiors to be improved. We discuss how this ambitious age requirement led to the selection of tens of thousands of red giants, and of thousands of main-sequence early F-type gravity-mode pulsators in order to deduce their internal rotation profile across stellar evolution. This asteroseismic observable will then be imported as key information into improved models of dwarfs and subgiants in the Milky Way as optimal modelling tools for ever better age-dating of the exoplanet hosts as the PLATO mission moves along. Additional calibrators and validators included in the scvPIC are a few thousands of binaries, a few hundreds of legacy and benchmark stars, a few hundred photometrically stable stars, and six transiting brown dwarfs.

Beyond orbital periods of 10 days, there is a dearth of known transiting gas giants. On longer orbits, planets are less affected by their host star, and become ideal probes of planet formation, migration and evolution. We report the discovery of a long period Neptune and two Saturns, each initially identified as single transits in the TESS photometry, and solved through additional transits from ground-based follow-up photometric observations by NGTS and ASTEP. High-resolution radial velocity mass measurements using CORALIE and HARPS confirm their planetary nature. From joint modelling of the photometric and spectroscopic data, we determine an orbital period of $43.12655_{-0.00017}^{+0.00012}~$days, radius of 3.65 ± 0.22 R⊕, and mass of $19.1_{-4.5}^{+4.9}~\mathrm{M_{\rm{\oplus }}}$ for NGTS-34 b, making it one of the longest period well-characterized transiting Neptunes. Orbiting a late F-type star, bright in the K-band (Kmag ≃ 7.9), it is amenable for cool atmosphere studies using JWST or Ariel. TOI-4940 b is a small Saturn on a $25.867811_{-0.000056}^{+0.000058}~$day orbit with a radius of 6.61 ± 0.37 R⊕ and an upper mass limit <89 M⊕. NGTS-35 b(=TOI-6669 b) is a larger Saturn on a 25.241192 ± 0.000022 day, moderately eccentric orbit ($e = 0.192_{-0.033}^{+0.037}$), with a radius of 10.90 ± 0.65 R⊕ and a mass of $152_{-19}^{+22}~\mathrm{M_{\rm{\oplus }}}$. With an assumed albedo A = 0.3, each of these planets has an equilibrium temperature below 700K, with NGTS-35 b especially cold at 450 K. These three giants add to the small but growing population of long period planets that can further our understanding of planet formation mechanisms.

Context. Gas giant planets orbiting low-mass stars (T-eff less than or similar to 4600 K) are uncommon outcomes of planet formation. Increasing the sample of well-characterised giants around early M dwarfs will enable population-level studies of their properties, offering valuable insights into their formation and evolutionary histories. Aims. We aim to confirm and characterise giant exoplanets transiting M dwarfs identified by the TESS mission. To this end, we have started the Gas giAnts Transiting 1Ow-mass Stars (GATOS) programme within the NIRPS guaranteed time observations (GTO). Methods. High-resolution spectroscopic data were obtained in the optical and near-infrared (nIR), combining HARPS and NIRPS. We derived radial velocities (RVs) via the cross-correlation function and implemented a novel post-processing procedure to further mitigate telluric contamination in the nIR. The resulting RVs were jointly fit with TESS and ground-based photometry to derive the orbital and physical parameters of the systems. Results. We present the GATOS programme and its first results. We confirm two gas giants transiting the low-mass stars TOI-3288 A (K9V, T-eff = 3933 +/- 48 K) and TOI-4666 (M2.5V, T-eff = 3512 +/- 36 K). TOI-3288 A hosts a hot Jupiter with a mass of 2.11 +/- 0.08 M-Jup and a radius of 1.00 +/- 0.03 R-Jup, with an orbital period of 1.43 days (T-eq = 1059 +/- 20 K). TOI-4666 hosts a 0.70 +/- 0.06 M-Jup warm Jupiter (T-eq = 713 +/- 14 K) with a radius of 1.11 +/- 0.04 R-Jup, with an orbital period of 2.91 days. At a population level, we identify a decrease in planetary mass with spectral type, whereby late M dwarfs host less massive giant planets than early M dwarfs. More massive gas giants that deviate from this trend are preferentially hosted by more metal-rich stars. Furthermore, we find an increased binarity fraction among low-mass stars hosting gas giants, which may play a role in enhancing giant planet formation around low-mass stars. Conclusions. These mass characterisations contribute to the growing catalogue of well-defined giant exoplanets around low-mass stars. The observed population trends agree with theoretical predictions, whereby higher metallicity can compensate for lower disc masses, and wide binary systems may influence planet formation and migration through Kozai-Lidov cycles or disc instabilities.

Context. Condensates are ubiquitous to all Solar System planets with significant (>10 mbar) atmospheres. The same is true for most exoplanets with characterised atmospheres, with even ultra-hot exoplanets being able to form clouds on their cooler nightsides. One high-interest condensate is titanium, a highly refractory element that as an oxide (TiO) is a potent optical absorber long believed to be a driver of thermal inversions in highly irradiated exoplanet atmospheres. Observations have shown that some ultra-hot Jupiters have strong thermal inversions despite being significantly Ti-depleted, likely due to cold trapping, raising doubts about whether TiO is the main cause of their inverted temperature structures. Aims. Our aim was to retrieve the titanium-to-iron ratio of the dayside atmosphere of the ultra-hot Jupiter WASP-189b to determine whether the full titanium budget is accounted for in the gas phase. Methods. We analysed thermal emission observations of WASP-189b taken with the HARPS and NIRPS spectrographs using different atmospheric retrieval prescriptions to infer the planet’s atmospheric thermal structure and composition. Results. We observed Fe and Ti signals in cross-correlation and measured a sub-solar Ti/Fe ratio for WASP-189b using both free and chemical equilibrium retrieval approaches. We find the Ti/Fe of the planetary atmosphere to be between 28% and 81% (1-σ bounds) that of the stellar value. Conclusions. The slight underabundance of Ti with respect to Fe on the dayside atmosphere of WASP-189b suggests that some titanium is missing from the gas phase, potentially due to a partial nightside cold trap. In the context of the ultra-hot Jupiter population, the onset of titanium in exoplanetary atmospheres appears to occur progressively, coinciding not with when thermal inversions begin but rather when the vapourisation threshold of titanium is reached on the nightside.

Context. LHS 3844 b (TOI-136b) is an ultra short-period, Earth-size exoplanet detected by TESS. It is one of the most favourable objects for atmospheric characterisation and study of its surface with the James Webb Space Telescope. However, the dynamical mass of this planet has not yet been measured. Aims. We aim to determine the mass of LHS 3844 b using high-precision radial velocity (RV) measurements and assess the robustness of the inferred signal across different noise and orbital modelling assumptions. Methods. We analyse 25 ESPRESSO RV observations within a fully Bayesian framework. We explore 15 competing RV models that differ in their treatment of correlated stellar variability (through different Gaussian process (GP) kernels) and long-term drifts. Marginal likelihoods are computed for all models and used for Bayesian model comparison and evidence-weighted parameter estimation. Results. The RV planetary signal is robustly detected across all models, and the inferred semi-amplitude remains stable under all tested noise and drift prescriptions. From the evidence-weighted posterior samples we derive a planetary mass of 2.27 ± 0.23 M⊕ and a bulk density of 5.67 ± 0.65 gcm−3, consistent with a predominantly rocky composition. Model comparison favours GP kernels including periodic or quasi-periodic components associated with stellar rotation and disfavours models with additional long-term drifts. Using interior-structure inference, we find that the core mass fraction is comparable to (or slightly smaller than) Earth's and only trace amounts of water are permitted, supporting a dry, terrestrial interior. We also investigate a tentative additional signal near ~6.9 days, but Bayesian model comparison does not provide conclusive support for its planetary interpretation. Conclusions. We report the first dynamical mass measurement of LHS 3844 b, confirming it as a dense, terrestrial ultra-short-period planet. With its exceptionally well-constrained bulk properties and extensive JWST programme, LHS 3844 b remains a benchmark target for studies of the atmospheres and surfaces of rocky exoplanets.

We report the discovery of TOI-4507 b, a transiting sub-Saturn with a density <0.2 g cm(-3) on a 10(5) days prograde orbit around a 700 Myr old F star. The transits were detected using data from TESS as well as the Antarctic telescope ASTEP. A joint analysis of the light curves and radial velocities from HARPS, FEROS, and CORALIE confirmed the planetary nature of the signal, by limiting the mass to be below 20 M-circle plus at 95% confidence. The radial velocities also exhibit the Rossiter-McLaughlin effect and imply that the planet orbits the star in a prograde orbit with a sky-projected obliquity lambda=-15(-44)(+50 degrees )(divided by lambda divided by < 80 degrees at 3 sigma). With these characteristics, TOI-4507 is one of the longest-period systems for which the stellar obliquity has been measured, and the planet is among the longest-period and youngest "superpuff" planets yet discovered.

We present the discovery of TIC-65910228 b / NGTS-38 b, a giant exoplanet with a radius of 1 . 081 +/- 0 . 047 R-J and a mass of 4 . 77(-0.37)(+0 . 39) M-J on a long-period ( 180 . 52797 +/- 0 . 00036 d), moderately eccentric ( e = 0 . 3086 +/- 0 . 010 ) orbit transiting a bright (V=10 . 230 +/- 0 . 020 mag) metal rich ([Fe/H] =0 . 33 +/- 0 . 09 'dex') F6V-F7V type host star. The planet was initially detected from a single transit in TESS Sector 33. A photometric monitoring campaign of 228 nights with NGTS detected a transit egress of the planet, which together with spectroscopic radial velocity monitoring with CORALIE and HARPS identified an orbital period of 180.5 d. These radial velocity measurements also showed the mass of the companion to be planetary. Additional transit observations coordinated by the TESS follow-up observing program allowed further confirmation and refinement of this period. With its relatively cool equilibrium temperature of 457 +/- 11 K, NGTS-38 b joins a small but growing population of well characterized transiting warm-Jupiters and has one of the longest periods of any discovered to date. The target is situated in the LOPS2 field of the upcoming PLATO mission which will allow for greater refinement of the system parameters and potential for the discovery of additional companions too small and/or too long-period to be seen by TESS or NGTS. NGTS-38 b's bright host star and wide orbital separation make it an attractive target for further study, including potential measurement of its spin-orbit alignment or targeted exomoon/ring searches.

Ground-based spectrographs operating in the near-infrared (NIR) regime are hampered by various absorption and emission features of Earth's atmosphere. While considerable attention has been paid to mitigating telluric absorption, correcting telluric emission features remains non-trivial and can significantly affect the observation of faint targets. We aim to develop and implement automated algorithms for sky background emission correction in the context of high-resolution spectroscopy. These empirical-based algorithms have been officially integrated into both NIRPS data reduction pipelines: NIRPS DRS and APERO DRS. Designed for flexibility, these techniques can be incorporated into the reduction workflow of any high-resolution spectrograph to improve the radial velocity (RV) performance. In our approach, a reference sky spectrum is first created by deep-stacking NIRPS sky calibration frames on a common wavelength grid and calculating the weighted median flux per pixel, separately for both the high-accuracy and high-efficiency instrument modes. This process is repeated for all spectral orders and for both the object and sky-calibration fibres: fibre A and fibre B, respectively. In this reference sky spectrum, the sky emission lines can be identified and used to construct a static library. During the data reduction process, the emission features in the library are individually scaled in terms of flux using two distinct techniques, each specific to the two DRS pipelines. Finally, they are locally subtracted from the science observations to minimise their noise contribution to the final spectrum. We find that the correction algorithms significantly improve the RV measurements obtained using both the cross-correlation function and line-by-line techniques, enabling NIRPS to achieve submetre-per-second precision in the NIR. The techniques have been successfully validated and demonstrated.

Small temperate planets are prime targets for exoplanet studies due to their possible similarities with the rocky planets in the Solar system. M dwarfs are promising hosts since the planetary signals are within our current detection capabilities. Gliese 12 b is a Venus-sized temperate planet orbiting a quiet M dwarf. We present here the first precise mass measurement of this small exoplanet. We performed a detailed analysis using HARPS-N (High Accuracy Radial velocity Planet Searcher for the Northern Hemisphere), ESPRESSO (Echelle Spectrograph for Rocky Exoplanets and Stable Spectroscopic Observations), and CARMENES (Calar Alto high-Resolution search for M dwarfs with Exoearths with Near-infrared and optical Echelle Spectrographs) radial velocities, along with new and archival TESS (Transiting Exoplanet Survey Satellite), CHEOPS (CHaracterising ExOPlanet Satellite), and MuSCAT2/3 (Multicolor Simultaneous Camera for studying Atmospheres of Transiting exoplanets) photometry data. From fitting the available data, we find that the planet has a radius of R-p = 0.93 +/- 0.06 R(circle plus )and a mass of M-p = 0.95(-0.30 )(+0.29)M(circle plus )(a3.2 sigma measurement of the semi-amplitude K = 0.67 +/- 0.21 m s(-1)), and is on an orbit with a period of 2.761418(-0.000055)(+0.000060)d. A variety of techniques were utilized to attenuate stellar activity signals. Gliese 12 b has an equilibrium temperature of T-eq = 317 +/- 8K, assuming an albedo of zero, and a density consistent with that of Earth and Venus (rho(p )= 6.4 +/- 2.4 g cm(-3)). We find that Gliese 12 b has a predominantly rocky interior and simulations indicate that it is unlikely to have retained any of its primordial gaseous envelope. The bulk properties of Gliese 12 b place it in an extremely sparsely populated region of both mass-radius and density-T-eq parameter space, making it a prime target for follow-up observations, including Lyman-alpha studies.

Studying planetary interactions in exoplanet systems informs theories of planet formation and evolution, providing essential context for understanding our own solar system. We combine spectroscopy, transit photometry, transit timing variations, and astrometry to characterize the TOI-201 system. The cotransiting system consists of a super-Earth, warm Jupiter, and massive companion at 5.8-, 53-, and 2900-day orbital periods, respectively. We perform dynamical simulations to study the past and future of the system. von-Zeipel-Kozai-Lidov oscillations emerge as the most plausible scenario to explain the outer companion's high orbital eccentricity, with planet-planet scattering a possible but less likely contender. Because of nonzero mutual inclinations between the planets, the system is visibly evolving on very short timescales, with the current cotransiting configuration ending in 200 years.

PLATO (PLAnetary Transits and Oscillations of stars) is ESA’s M3 mission and designed to detect and characterize extrasolar planets by high-precision, long-term photometric and asteroseismic monitoring of a large number of stars. PLATO will detect small planets around bright stars, including terrestrial planets in the habitable zone of solar-like stars. With asteroseismology of their host stars and complementary radial velocity observation from ground-based telescopes, planets will be characterized for their radius, mass, and age with high accuracy. PLATO will provide us the first large-scale catalogue of well-characterized small planets up to intermediate orbital periods, relevant for a meaningful comparison to planet formation theories and to better understand planet evolution. It will make possible comparative exoplanetology to place our solar system planets in a broader context. PLATO will study host stars using asteroseismology, allowing us to determine the stellar properties with high accuracy, substantially enhancing our knowledge of stellar structure and evolution.PLATO is scheduled for a launch date in Q1 2027. At this point, spring 2026, the payload including 26 wide-angle cameras with 12cm aperture each is finalized and integrated on the satellite platform. Final spacecraft and ground-segment tests will be performed during 2026. This presentation will give an overview of the PLATO science goals, of its instrument and mission profile status as well as the planned data releases.

We report the discovery and characterization of the multiplanetary system around TOI-4311, a K dwarf kinematically between the Galactic thick disc and Hercules stream. TOI-4311 hosts an ultra-short-period super-Earth (P similar to 0.99 d, 1 . 376(-0.080)(+0 . 077) R-circle plus) and a longer period sub-Neptune (P similar to 15 d, 2.47(-0 . 11)(+0.12) R-circle plus) that was first detected in the Transiting Exoplanet Survey Satellite photometry. Using follow-up observations with CHaracterising ExOPlanet Satellite and High Accuracy Radial Velocity Planet Searcher (HARPS), we refine the planetary radius of both planets, derive the mass of planet b ( 4 . 5(-1.4)(+1 . 5) M-circle plus), and confirm the planetary nature of planet c. Intriguingly, a third periodic signal is clearly detected in our HARPS Radial Velocities (RVs) that we cannot link to stellar activity. This signal could be attributed to a third planet (P similar to 38 d, Msin(i) = 26.4(-6.8)(+6 . 3) M-circle plus) in the system; however, with the current photometric data set we do not find a transit. Our dynamical analysis highlights that this potential outer planet would remain stable. Using the precise radius and mass for TOI-4311 b, we model its interior structure and find that it is very dense given the host star's galactic kinematics and chemistry. Hence, this system could challenge current formation theories and provide insights into planet formation across the galaxy.

Tidal interactions in close stellar binaries are central to their orbital and rotational evolution, making observational tests of theoretical predictions essential for our understanding of the evolution of these, as well as close exoplanetary systems. Such tests require precise measurements of the orbital eccentricity and stellar rotation. The EBLM (Eclipsing Binary Low Mass) survey delivers a homogeneous sample of eclipsing binaries, composed of F/G/K primaries and M-dwarf (or low-mass K-dwarf) secondaries. We analyse 68 unequal mass binaries (0 . 1 <= q <= 0 . 6, where q is the mass ratio), with measurable primary star rotation rates from TESS, and over a decade of radial velocity observations. This sample probes the critical regime where tidal effects are expected to transition between being efficient and inefficient. We find that similar to 75 per cent of our sample has circularized, with eccentric systems confined to P-orb greater than or similar to 3 d, with modest eccentricities (e < 0.25). Roughly similar to 78 per cent of our sample is synchronized, with nearly all binaries within a 3-d orbital period residing in a well-defined 'synchronization zone'. Beyond this, a minority of asynchronous systems persist, which cannot be easily explained by our application of current tidal mechanisms or by differential rotation.

The Neptunian desert is a distinct lack of Neptune-sized planets at short orbital periods, purportedly carved by photoevaporation and tidal circularisation following high-eccentricity migration. Constraining these processes and how they vary across different hoststar spectral types requires detailed characterisation of the planets in the desert and around its boundaries. In this study, we confirm the planetary nature of a massive super-Neptune identified by TESS around the M0 dwarf TOI-672. We analysed photometry from TESS and ExTrA and precise radial velocity measurements taken with the recently commissioned Near-InfraRed Planet Searcher (NIRPS) and HARPS spectrographs. We measured a planetary orbital period of 3.634 days, a radius of 5.31(-0.26)(+0.24) R-circle plus, and mass of 50.9(-4.4)(+4.5) M-circle plus. Our findings place TOI-672 b within the Neptunian ridge, a pile-up of planets from 3-5 days at the Neptunian desert boundary. We used a novel approach to determine the desert boundaries in period-radius space and instellation-radius space, and for the first time, we compared the Neptunian desert boundaries for planets orbiting FGK versus M dwarf stars. We determined that the boundary ridge shifts slightly inwards from 3.3 +/- 1.4 days for FGK host stars to 2.2 +/- 1.0 days for M dwarf host stars. Statistically, these values do not significantly differ from each other, and the shift to shorter periods for M dwarf planets is smaller than what theoretical photoevaporation models predict. We also find that TOI-672 b is a single-planet system within the sensitivity limits of our RV and TTV datasets.