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The study of spiral structures in protoplanetary disks is of great importance for understanding the processes in the disks, including planet formation. Bright spiral arms were detected in the disk of young star CQ Tau by Uyama et al. in the H and L bands. The spiral arms are located inside the gap in millimeter-sized dust, discovered earlier using Atacama Large Millimeter/submillimeter Array observations. To explain the gap, Ubeira Gabellini et al. proposed the existence of a planet with the semimajor axis of 20 au. We obtained multi-epoch observations of a spiral feature in the circumstellar envelope of CQ Tau in the I c band using a novel technique of differential speckle polarimetry. The observations covering a period from 2015 to 2021 allow us to estimate the pattern speed of the spiral: −0.°2 ± 1.°1 yr−1 (68% credible interval; positive value indicates counterclockwise rotation), assuming a face-on orientation of the disk. This speed is significantly smaller than expected for a companion-induced spiral, if the perturbing body has a semimajor axis of 20 au. We emphasize that the morphology of the spiral structure is likely to be strongly affected by shadows of a misaligned inner disk detected by Eisner et al.

Characterizing the bulk compositions of transiting exoplanets within the M dwarf radius valley offers a unique means to establish whether the radius valley emerges from an atmospheric mass-loss process or is imprinted by planet formation itself. We present the confirmation of such a planet orbiting an early-M dwarf (T mag = 11.0294 ± 0.0074, M s = 0.513 ± 0.012 M ⊙, R s = 0.515 ± 0.015 R ⊙, and T eff = 3690 ± 50 K): TOI-1695 b (P = 3.13 days and Rp=1.90−0.14+0.16R⊕ ). TOI-1695 b’s radius and orbital period situate the planet between model predictions from thermally driven mass loss versus gas depleted formation, offering an important test case for radius valley emergence models around early-M dwarfs. We confirm the planetary nature of TOI-1695 b based on five sectors of TESS data and a suite of follow-up observations including 49 precise radial velocity measurements taken with the HARPS-N spectrograph. We measure a planetary mass of 6.36 ± 1.00 M ⊕, which reveals that TOI-1695 b is inconsistent with a purely terrestrial composition of iron and magnesium silicate, and instead is likely a water-rich planet. Our finding that TOI-1695 b is not terrestrial is inconsistent with the planetary system being sculpted by thermally driven mass loss. We present a statistical analysis of seven well-characterized planets within the M dwarf radius valley demonstrating that a thermally driven mass-loss scenario is unlikely to explain this population.

We report the confirmation of three exoplanets transiting TOI-4010 (TIC-352682207), a metal-rich K dwarf observed by the Transiting Exoplanet Survey Satellite in Sectors 24, 25, 52, and 58. We confirm these planets with the High Accuracy Radial velocity Planet Searcher for the Northern Hemisphere radial velocity observations and measure their masses with 8−12% precision. TOI-4010 b is a sub-Neptune (P = 1.3 days, Rp=3.02−0.08+0.08R⊕ , Mp=11.00−1.27+1.29M⊕ ) in the hot-Neptune desert, and is one of the few such planets with known companions. Meanwhile, TOI-4010 c (P = 5.4 days, Rp=5.93−0.12+0.11R⊕ , Mp=20.31−2.11+2.13M⊕ ) and TOI-4010 d (P = 14.7 days, Rp=6.18−0.14+0.15R⊕ , Mp=38.15−3.22+3.27M⊕ ) are similarly sized sub-Saturns on short-period orbits. Radial velocity observations also reveal a super-Jupiter-mass companion called TOI-4010 e in a long-period, eccentric orbit (P ∼ 762 days and e ∼ 0.26 based on available observations). TOI-4010 is one of the few systems with multiple short-period sub-Saturns to be discovered so far.

We present the discovery of TOI-1420b, an exceptionally low-density (ρ = 0.08 ± 0.02 g cm−3) transiting planet in a P = 6.96 days orbit around a late G-dwarf star. Using transit observations from TESS, LCOGT, Observatoire Privé du Mont, Whitin, Wendelstein, OAUV, Ca l’Ou, and KeplerCam, along with radial velocity observations from HARPS-N and NEID, we find that the planet has a radius of R p = 11.9 ± 0.3R ⊕ and a mass of M p = 25.1 ± 3.8M ⊕. TOI-1420b is the largest known planet with a mass less than 50M ⊕, indicating that it contains a sizeable envelope of hydrogen and helium. We determine TOI-1420b’s envelope mass fraction to be fenv=82−6+7% , suggesting that runaway gas accretion occurred when its core was at most four to five times the mass of the Earth. TOI-1420b is similar to the planet WASP-107b in mass, radius, density, and orbital period, so a comparison of these two systems may help reveal the origins of close-in low-density planets. With an atmospheric scale height of 1950 km, a transmission spectroscopy metric of 580, and a predicted Rossiter–McLaughlin amplitude of about 17 m s−1, TOI-1420b is an excellent target for future atmospheric and dynamical characterization.

NASA’s Transiting Exoplanet Survey Satellite (TESS) is an all-sky survey mission designed to find transiting exoplanets orbiting nearby bright stars. It has identified more than 329 transiting exoplanets, and almost 6000 candidates remain unvalidated. In this manuscript, we discuss the findings from the ongoing Validation of Transiting Exoplanets using Statistical Tools (VaTEST) project, which aims to validate new exoplanets for further characterization. We validated 11 new exoplanets by examining the light curves of 24 candidates using the LATTE and TESS-Plot tools and computing the false-positive probabilities using the statistical validation tool TRICERATOPS. These include planets suitable for atmospheric characterization using transmission spectroscopy (TOI-2194b), emission spectroscopy (TOI-3082b and TOI-5704b) and for both transmission and emission spectroscopy (TOI-672b, TOI-1694b, and TOI-2443b). Our validated planets have one super-Earth (TOI-2194b) orbiting a bright (V = 8.42 mag), metal-poor ([Fe/H] = −0.3720 ± 0.1) star, and one short-period Neptune-like planet (TOI-5704) in the hot-Neptune desert. In total, we validated one super-Earth, seven sub-Neptunes, one Neptune-like, and two sub-Saturn or super-Neptune-like exoplanets. Additionally, we identify five likely planet candidates (TOI-323, TOI-1180, TOI-2200, TOI-2408, and TOI-3913), which can be further studied to establish their planetary nature.

We confirm the planetary nature of a pair of transiting sub-Neptune exoplanets orbiting the bright F-type subgiant star TOI-6054 (V = 8.02, K = 6.673) as a part of the OrCAS radial velocity survey using WIYN/NEID observations. We find that TOI-6054b and TOI-6054c have radii of 2.64 ± 0.15R⊕ and 2.82 ± 0.17R⊕, respectively, and masses of 12.5 ± 1.7M⊕ and 9.3 ± 1.9M⊕. The planets have zero-albedo equilibrium temperatures of 1360 ± 32 K and 1143 ± 28 K. The host star has expanded and will evolve off of the main sequence within the next ∼500 Myr, and the resulting increase in stellar luminosity has more than doubled the stellar flux the two planets receive compared to the start of the host star’s main-sequence phase. Consequently, TOI-6054b may be losing some of its primordial hydrogen/helium atmosphere—if it has one. Based on dynamical simulations performed using the orbital parameters of the two planets, TOI-6054b, and TOI-6054c are very likely in a 5:3 mean motion resonance. The TOI-6054 system thus has the potential to be an excellent candidate for future atmospheric follow-up observations, with two similarly sized sub-Neptunes around a bright star. We also estimate that if TOI-6054b is currently losing its H/He atmosphere, this should be observable from space and from the ground.

We confirm the planetary nature of a pair of transiting sub-Neptune exoplanets orbiting the bright F-type sub-giant star TOI-6054 (\\(V=8.02\\), \\(K=6.673\\)) as a part of the OrCAS radial velocity survey using WIYN/NEID observations. We find that TOI-6054b and TOI-6054c have radii of \\(2.65 \\pm 0.15\\) \\(R_{\\oplus}\\) and \\(2.81 \\pm 0.18\\) \\(R_{\\oplus}\\), respectively, and masses of \\(12.4 \\pm 1.7\\) \\(M_{\\oplus}\\) and \\(9.2 \\pm 2.0\\) \\(M_{\\oplus}\\). The planets have zero-albedo equilibrium temperatures of \\(1360 \\pm 33\\) K and \\(1144 \\pm 28\\) K. The host star has expanded and will evolve off of the Main Sequence within the next \\(\\sim\\)500 Myr, and the resulting increase in stellar luminosity has more than doubled the stellar flux the two planets receive compared to the start of the host star's main sequence phase. Consequently, TOI-6054b may be losing some of its primordial H/He atmosphere -- if it has one. Based on dynamical simulations performed using the orbital parameters of the two planets, TOI-6054b, and TOI-6054c are very likely in a 5:3 mean motion resonance. The TOI-6054 system thus has the potential to be an excellent candidate for future atmospheric follow-up observations, with two similarly sized sub-Neptunes around a bright star. We also estimate that if TOI-6054b is currently losing its H/He atmosphere this should be observable from space and from the ground.

Characterizing the bulk compositions of transiting exoplanets within the M dwarf radius valley offers a unique means to establish whether the radius valley emerges from an atmospheric mass loss process or is imprinted by planet formation itself. We present the confirmation of such a planet orbiting an early M dwarf (\\(T_{\\rm mag} = 11.0294 \\pm 0.0074, M_s = 0.513 \\pm 0.012\\ M_\\odot, R_s = 0.515 \\pm 0.015\\ R_\\odot, T_{\\rm eff} =3690\\pm 50 K\\)): TOI-1695 b (\\(P = 3.13\\) days, \\(R_p = 1.90^{+0.16}_{-0.14}\\ R_\\oplus\\)). TOI-1695 b's radius and orbital period situate the planet between model predictions from thermally-driven mass loss versus gas depleted formation, offering an important test case for radius valley emergence models around early M dwarfs. We confirm the planetary nature of TOI-1695 b based on five sectors of TESS data and a suite of follow-up observations including 49 precise radial velocity measurements taken with the HARPS-N spectrograph. We measure a planetary mass of \\(6.36 \\pm 1.00\\ M_\\oplus\\), which reveals that TOI-1695 b is inconsistent with a purely terrestrial composition of iron and magnesium silicate, and instead is likely a water-rich planet. Our finding that TOI-1695 b is not terrestrial is inconsistent with the planetary system being sculpted by thermally driven mass loss. We present a statistical analysis of seven well-characterized planets within the M dwarf radius valley demonstrating that a thermally-driven mass loss scenario is unlikely to explain this population.

HIP 9618 (HD 12572, TOI-1471, TIC 306263608) is a bright (\\(G=9.0\\) mag) solar analogue. TESS photometry revealed the star to have two candidate planets with radii of \\(3.9 \\pm 0.044\\) \\(R_\\oplus\\) (HIP 9618 b) and \\(3.343 \\pm 0.039\\) \\(R_\\oplus\\) (HIP 9618 c). While the 20.77291 day period of HIP 9618 b was measured unambiguously, HIP 9618 c showed only two transits separated by a 680-day gap in the time series, leaving many possibilities for the period. To solve this issue, CHEOPS performed targeted photometry of period aliases to attempt to recover the true period of planet c, and successfully determined the true period to be 52.56349 d. High-resolution spectroscopy with HARPS-N, SOPHIE and CAFE revealed a mass of \\(10.0 \\pm 3.1 M_\\oplus\\) for HIP 9618 b, which, according to our interior structure models, corresponds to a \\(6.8\\pm1.4\\%\\) gas fraction. HIP 9618 c appears to have a lower mass than HIP 9618 b, with a 3-sigma upper limit of \\(< 18M_\\oplus\\). Follow-up and archival RV measurements also reveal a clear long-term trend which, when combined with imaging and astrometric information, reveal a low-mass companion (\\(0.08^{+0.12}_{-0.05} M_\\odot\\)) orbiting at \\(26^{+19}_{-11}\\) au. This detection makes HIP 9618 one of only five bright (\\(K<8\\) mag) transiting multi-planet systems known to host a planet with \\(P>50\\) d, opening the door for the atmospheric characterisation of warm (\\(T_{\\rm eq}<750\\) K) sub-Neptunes.

We report the confirmation of three exoplanets transiting TOI-4010 (TIC-352682207), a metal-rich K dwarf observed by TESS in Sectors 24, 25, 52, and 58. We confirm these planets with HARPS-N radial velocity observations and measure their masses with 8 - 12% precision. TOI-4010 b is a sub-Neptune (\\(P = 1.3\\) days, \\(R_{p} = 3.02_{-0.08}^{+0.08}~R_{\\oplus}\\), \\(M_{p} = 11.00_{-1.27}^{+1.29}~M_{\\oplus}\\)) in the hot Neptune desert, and is one of the few such planets with known companions. Meanwhile, TOI-4010 c (\\(P = 5.4\\) days, \\(R_{p} = 5.93_{-0.12}^{+0.11}~R_{\\oplus}\\), \\(M_{p} = 20.31_{-2.11}^{+2.13}~M_{\\oplus}\\)) and TOI-4010 d (\\(P = 14.7\\) days, \\(R_{p} = 6.18_{-0.14}^{+0.15}~R_{\\oplus}\\), \\(M_{p} = 38.15_{-3.22}^{+3.27}~M_{\\oplus}\\)) are similarly-sized sub-Saturns on short-period orbits. Radial velocity observations also reveal a super-Jupiter-mass companion called TOI-4010 e in a long-period, eccentric orbit (\\(P \\sim 762\\) days and \\(e \\sim 0.26\\) based on available observations). TOI-4010 is one of the few systems with multiple short-period sub-Saturns to be discovered so far.