Explore the vast range of titles available.

With its imaged debris disk of dust, its evaporating exocomets, and an imaged giant planet, the young (~23 Myr) β Pictoris system is a unique proxy for detailed studies of planet formation processes as well as planet–disk interactions. Here, we study ten years of European Southern Observatory/High Accuracy Radial Velocity Planet Searcher (HARPS) high-resolution spectroscopic data of β Pictoris. After removing the radial velocity (RV) signals arising from the δ Scuti pulsations of the star, a ~1,200-d periodic signal remains, which, within our current knowledge, we can only attribute to a second planet in the system. The β Pic c mass is about nine times the mass of Jupiter; it orbits at ~2.7 au on an eccentric (e ~ 0.24) orbit. More RV data are needed to obtain more precise estimates of the properties of β Pic c. The current modelling of the planet’s properties and the dynamic of the whole system has to be reinvestigated in light of this detection.Radial velocity data of the young β Pictoris system acquired by HARPS and spanning 15 years show evidence of β Pic c, a gas giant of ~9 Jupiter masses orbiting on an eccentric orbit at ~2.4 au from the star, near the theoretical snowline. Both β Pic b and c, located close to the star, may have formed in situ by core accretion.

We present three-dimensional (3D) maps of Jupiter's atmospheric circulation at cloud-top level from Doppler-imaging data obtained in the visible domain with JIVE, the second node of the JOVIAL network, which is mounted on the Dunn Solar Telescope at Sunspot, New Mexico. We report on 12 nights of observations between May 4 and May 30, 2018, representing a total of about 80 hours. Firstly, the average zonal wind profile derived from our data is compatible with that derived from cloud-tracking measurements performed on Hubble Space Telescope images obtained in April 2018 from the Outer Planet Atmospheres Legacy (OPAL) program. Secondly, we present the first ever two-dimensional maps of Jupiter's atmospheric circulation from Doppler measurements. The zonal velocity map highlights well-known atmospheric features, such as the equatorial hot spots and the Great Red Spot (GRS). In addition to zonal winds, we derive meridional and vertical velocity fields from the Doppler data. The motions attributed to vertical flows are mainly located at the boundary between the equatorial belts and tropical zones, which could indicate active motion in theses regions. Qualitatively, these results compare well to recent Juno data that have unveiled the three-dimensional structure of Jupiter's wind field. To the contrary, the motions attributed to meridional circulation are very different from what is obtained by cloud tracking, except at the GRS. Because of limitations with data resolution and processing techniques, we acknowledge that our measurement of vertical or meridional flows of Jupiter are still to be confirmed.

We recently proposed a new lucky imaging technique, the Power Spectrum Extended (PSE), adapted for image reconstruction of short-exposure astronomical images in case of weak turbulence or partial adaptive optics correction. In this communication we show applications of this technique to observations of about 30 binary stars in H band with the 1m telescope of the Calern C2PU observatory. We show some images reconstructed at the diffraction limit of the telescope and provide measurements of relative astrometry and photometry of observed couples.

On December 2021, a new camera box for two-colour simultaneous visible photometry was successfully installed on the ASTEP telescope at the Concordia station in Antarctica. The new focal box offers increased capabilities for the ASTEP+ project. The opto-mechanical design of the camera was described in a previous paper. Here, we focus on the laboratory tests of each of the two cameras, the low-temperature behaviour of the focal box in a thermal chamber, the on-site installation and alignment of the new focal box on the telescope, the measurement of the turbulence in the tube and the operation of the telescope equipped with the new focal box. We also describe the data acquisition and the telescope guiding procedure and provide a first assessment of the performances reached during the first part of the 2022 observation campaign. Observations of the WASP19 field, already observed previously with ASTEP, demonstrates an improvement of the SNR by a factor 1.7, coherent with an increased number of photon by a factor of 3. The throughput of the two cameras is assessed both by calculation of the characteristics of the optics and quantum efficiency of the cameras, and by direct observations on the sky. We find that the ASTEP+ two-colour transmission curves (with a dichroic separating the fluxes at 690nm) are similar to those of GAIA in the blue and red channels, but with a lower transmission in the ASTEP+ red channel leading to a 1.5 magnitude higher B-R value compared to the GAIA B-R value. With this new setting, the ASTEP+ telescope will ensure the follow-up and the characterization of a large number of exoplanetary transits in the coming years in view of the future space missions JWST and Ariel.

We report the discovery and characterization of three giant exoplanets orbiting solar-analog stars, detected by the \\tess space mission and confirmed through ground-based photometry and radial velocity (RV) measurements taken at La Silla observatory with \\textit{FEROS}. TOI-2373\\,b is a warm Jupiter orbiting its host star every \\(\\sim\\) 13.3 days, and is one of the two most massive known exoplanet with a precisely determined mass and radius around a star similar to the Sun, with an estimated mass of m\\(_p\\) = \\(9.3^{+0.2}_{-0.2}\\,M_{\\mathrm{jup}}\\), and a radius of \\(r_p\\) = \\(0.93^{+0.2}_{-0.2}\\,R_{\\mathrm{jup}}\\). With a mean density of \\(\\rho = 14.4^{+0.9}_{-1.0}\\,\\mathrm{g\\,cm}^{-3}\\), TOI-2373\\,b is among the densest planets discovered so far. TOI-2416\\,b orbits its host star on a moderately eccentric orbit with a period of \\(\\sim\\) 8.3 days and an eccentricity of \\(e\\) = \\(0.32^{+0.02}_{-0.02}\\). TOI-2416\\,b is more massive than Jupiter with \\(m_p\\) = 3.0\\(^{+0.10}_{-0.09}\\,M_{\\mathrm{jup}}\\), however is significantly smaller with a radius of \\(r_p\\) = \\(0.88^{+0.02}_{-0.02},R_{\\mathrm{jup}}\\), leading to a high mean density of \\(\\rho = 5.4^{+0.3}_{-0.3}\\,\\mathrm{g\\,cm}^{-3}\\). TOI-2524\\,b is a warm Jupiter near the hot Jupiter transition region, orbiting its star every \\(\\sim\\) 7.2 days on a circular orbit. It is less massive than Jupiter with a mass of \\(m_p\\) = \\(0.64^{+0.04}_{-0.04}\\,M_{\\mathrm{jup}}\\), and is consistent with an inflated radius of \\(r_p\\) = \\(1.00^{+0.02}_{-0.03}\\,R_{\\mathrm{jup}}\\), leading to a low mean density of \\(\\rho = 0.79^{+0.08}_{-0.08}\\,\\mathrm{g\\,cm}^{-3}\\). The newly discovered exoplanets TOI-2373\\,b, TOI-2416\\,b, and TOI-2524\\,b have estimated equilibrium temperatures of \\(860^{+10}_{-10}\\) K, \\(1080^{+10}_{-10}\\) K, and \\(1100^{+20}_{-20}\\) K, respectively, placing them in the sparsely populated transition zone between hot and warm Jupiters.

We present numerical simulations and laboratory experiments on an eight-octant phase-mask (EOPM) coronagraph. The numerical simulations suggest that an achievable contrast for the EOPM coronagraph can be greatly improved as compared to that of a four-quadrant phase-mask (FQPM) coronagraph for a partially resolved star. On-sky transmission maps reveal that the EOPM coronagraph has relatively high optical throughput, a small inner working angle, and large discovery space. We have manufactured an eight-segment phase mask utilizing a nematic liquid-crystal device, which can be easily switched between the FQPM and the EOPM modes. The laboratory experiments demonstrate that the EOPM coronagraph has a better tolerance of the tip-tilt error than the FQPM one. We also discuss feasibility of a fully achromatic and high-throughput EOPM coronagraph utilizing a polarization interferometric technique.

Hot jupiters (P < 10 d, M > 60 \\(\\mathrm{M}_\\oplus\\)) are almost always found alone around their stars, but four out of hundreds known have inner companion planets. These rare companions allow us to constrain the hot jupiter's formation history by ruling out high-eccentricity tidal migration. Less is known about inner companions to hot Saturn-mass planets. We report here the discovery of the TOI-2000 system, which features a hot Saturn-mass planet with a smaller inner companion. The mini-neptune TOI-2000 b (\\(2.70 \\pm 0.15 \\,\\mathrm{R}_\\oplus\\), \\(11.0 \\pm 2.4 \\,\\mathrm{M}_\\oplus\\)) is in a 3.10-day orbit, and the hot saturn TOI-2000 c (\\(8.14^{+0.31}_{-0.30} \\,\\mathrm{R}_\\oplus\\), \\(81.7^{+4.7}_{-4.6} \\,\\mathrm{M}_\\oplus\\)) is in a 9.13-day orbit. Both planets transit their host star TOI-2000 (TIC 371188886, V = 10.98, TESS magnitude = 10.36), a metal-rich ([Fe/H] = \\(0.439^{+0.041}_{-0.043}\\)) G dwarf 174 pc away. TESS observed the two planets in sectors 9-11 and 36-38, and we followed up with ground-based photometry, spectroscopy, and speckle imaging. Radial velocities from CHIRON, FEROS, and HARPS allowed us to confirm both planets by direct mass measurement. In addition, we demonstrate constraining planetary and stellar parameters with MIST stellar evolutionary tracks through Hamiltonian Monte Carlo under the PyMC framework, achieving higher sampling efficiency and shorter run time compared to traditional Markov chain Monte Carlo. Having the brightest host star in the V band among similar systems, TOI-2000 b and c are superb candidates for atmospheric characterization by the JWST, which can potentially distinguish whether they formed together or TOI-2000 c swept along material during migration to form TOI-2000 b.

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 6,000 candidates remain unvalidated. In this manuscript, we discuss the findings from the ongoing VaTEST (Validation of Transiting Exoplanets using Statistical Tools) 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); One super-Earth (TOI-2194b) orbiting a bright (V = 8.42 mag), metal-poor ([Fe/H] = -0.3720 \\(\\pm\\) 0.1) star; one short-period Neptune-like planet (TOI-5704) in the Hot Neptune Desert. In total, we validated 1 super-Earth, 7 sub-Neptunes, 1 Neptune-like, and 2 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.

While the sample of confirmed exoplanets continues to increase, the population of transiting exoplanets around early-type stars is still limited. These planets allow us to investigate the planet properties and formation pathways over a wide range of stellar masses and study the impact of high irradiation on hot Jupiters orbiting such stars. We report the discovery of TOI-615b, TOI-622b, and TOI-2641b, three Saturn-mass planets transiting main sequence, F-type stars. The planets were identified by the Transiting Exoplanet Survey Satellite (TESS) and confirmed with complementary ground-based and radial velocity observations. TOI-615b is a highly irradiated (\\(\\sim\\)1277 \\(F_{\\oplus}\\)) and bloated Saturn-mass planet (1.69$^{+0.05}_{-0.06}$$R_{Jup}\\( and 0.43\\)^{+0.09}_{-0.08}$$M_{Jup}\\() in a 4.66 day orbit transiting a 6850 K star. TOI-622b has a radius of 0.82\\)^{+0.03}_{-0.03}$$R_{Jup}\\( and a mass of 0.30\\)^{+0.07}_{-0.08}\\(~\\)M_{Jup}\\( in a 6.40 day orbit. Despite its high insolation flux (\\)\\sim\\(600 \\)F_{\\oplus}\\(), TOI-622b does not show any evidence of radius inflation. TOI-2641b is a 0.39\\)^{+0.02}_{-0.04}$$M_{Jup}\\( planet in a 4.88 day orbit with a grazing transit (b = 1.04\\)^{+0.05}_{-0.06 }\\() that results in a poorly constrained radius of 1.61\\)^{+0.46}_{-0.64}$$R_{Jup}\\(. Additionally, TOI-615b is considered attractive for atmospheric studies via transmission spectroscopy with ground-based spectrographs and \\)\\textit{JWST}$. Future atmospheric and spin-orbit alignment observations are essential since they can provide information on the atmospheric composition, formation and migration of exoplanets across various stellar types.

We present ground and space-based photometric observations of TOI-270 (L231-32), a system of three transiting planets consisting of one super-Earth and two sub-Neptunes discovered by TESS around a bright (K-mag=8.25) M3V dwarf. The planets orbit near low-order mean-motion resonances (5:3 and 2:1), and are thus expected to exhibit large transit timing variations (TTVs). Following an extensive observing campaign using 8 different observatories between 2018 and 2020, we now report a clear detection of TTVs for planets c and d, with amplitudes of \\(\\sim\\)10 minutes and a super-period of \\(\\sim\\)3 years, as well as significantly refined estimates of the radii and mean orbital periods of all three planets. Dynamical modeling of the TTVs alone puts strong constraints on the mass ratio of planets c and d and on their eccentricities. When incorporating recently published constraints from radial velocity observations, we obtain masses of \\(M_{\\mathrm{b}}=1.48\\pm0.18\\,M_\\oplus\\), \\(M_{c}=6.20\\pm0.31\\,M_\\oplus\\) and \\(M_{\\mathrm{d}}=4.20\\pm0.16\\,M_\\oplus\\) for planets b, c and d, respectively. We also detect small, but significant eccentricities for all three planets : \\(e_\\mathrm{b} =0.0167\\pm0.0084\\), \\(e_{c} =0.0044\\pm0.0006\\) and \\(e_{d} = 0.0066\\pm0.0020\\). Our findings imply an Earth-like rocky composition for the inner planet, and Earth-like cores with an additional He/H\\(_2\\)O atmosphere for the outer two. TOI-270 is now one of the best-constrained systems of small transiting planets, and it remains an excellent target for atmospheric characterization.