The SpHere INfrared Exoplanet (SHINE) project is a 500-star survey performed with SPHERE on the Very Large Telescope for the purpose of directly detecting new substellar companions and understanding their formation and early evolution. Here we present an initial statistical analysis for a subsample of 150 stars spanning spectral types from B to M that are representative of the full SHINE sample. Our goal is to constrain the frequency of substellar companions with masses between 1 and 75 M Jup and semimajor axes between 5 and 300 au. For this purpose, we adopt detection limits as a function of angular separation from the survey data for all stars converted into mass and projected orbital separation using the BEX-COND-hot evolutionary tracks and known distance to each system. Based on the results obtained for each star and on the 13 detections in the sample, we use a Markov chain Monte Carlo tool to compare our observations to two different types of models. The first is a parametric model based on observational constraints, and the second type are numerical models that combine advanced core accretion and gravitational instability planet population synthesis. Using the parametric model, we show that the frequencies of systems with at least one substellar companion are 23.0 +13.5 −9.7 %, 5.8 +4.7 −2.8 %, and 12.6 +12.9 −7.1 % for BA, FGK, and M stars, respectively. We also demonstrate that a planet-like formation pathway probably dominates the mass range from 1-75 M Jup for companions around BA stars, while for M dwarfs, brown dwarf binaries dominate detections. In contrast, a combination of binary star-like and planet-like formation is required to best fit the observations for FGK stars. Using our population model and restricting our sample to FGK stars, we derive a frequency of 5.7 +3.8 −2.8 %, consistent with predictions from the parametric model. More generally, the frequency values that we derive are in excellent agreement with values obtained in previous studies.

Context. Giant planets in short-period orbits around bright stars represent optimal candidates for atmospheric and dynamical studies of exoplanetary systems. Aims. We aim to analyse four transits of WASP-33b observed with the optical high-resolution HARPS-N spectrograph to confirm its nodal precession, study its atmosphere, and investigate the presence of star-planet interactions. Methods. We extracted the mean line profiles of the spectra using the least-squares deconvolution method, and we analysed the Doppler shadow and the radial velocities. We also derived the transmission spectrum of the planet, correcting it for the stellar contamination due to rotation, centre-to-limb variations, and pulsations. Results. We confirm the previously discovered nodal precession of WASP-33b, almost doubling the time coverage of the inclination and projected spin-orbit angle variation. We find that the projected obliquity reached a minimum in 2011, and we used this constraint to derive the geometry of the system, and in particular its obliquity at that epoch (ϵ = 113.99° ± 0.22°) and the inclination of the stellar spin axis (is = 90.11° ± 0.12°). We also derived the gravitational quadrupole moment of the star J2 = (6.73 ± 0.22) × 10−5, which we find to be in close agreement with the theoretically predicted value. Small systematics errors are computed by shifting the date of the minimum projected obliquity. We present detections of Hα and Hβ absorption in the atmosphere of the planet, with a contrast almost twice as small as that previously detected in the literature. We also find evidence for the presence of a pre-transit signal, which repeats in all four analysed transits and should thus be related to the planet. The most likely explanation lies in a possible excitation of a stellar pulsation mode by the presence of the planetary companion. Conclusions. A future common analysis of all available datasets in the literature will help shed light on the possibility that the observed Balmer lines’ transit depth variations are related to stellar activity and pulsation, and to set constraints on the planetary temperature–pressure structure and thus on the energetics possibly driving atmospheric escape. A complete orbital phase coverage of WASP-33b with high-resolution spectroscopic (and spectro-polarimetric) observations could help us to understand the nature of the pre-transit signal.

Stellar associations can be discerned as overdensities of sources not only in the physical space but also in the velocity space. The common motion of their members, gradually eroded by the galactic tidal field, is partially reminiscent of the initial kinematic structure. Using recent data from Gaia EDR3, combined with radial velocities from GALAH and APOGEE, we traced back the present positions of stars belonging to Upper Scorpius, a subgroup of Scorpius-Centaurus, the nearest OB association. About one half of the subgroup (the “clustered” population) appears composed of many smaller entities, which were in a more compact configuration in the past. The presence of a kinematic duality is reflected into an age spread between this younger clustered population and an older diffuse population, in turn confirmed by a different fraction fD of disc-bearing stars (fD = 0.24 ± 0.02 versus fD = 0.10 ± 0.01). Star formation in Upper Scorpius appears to have lasted more than 10 Myr and proceeded in small groups that, after a few Myr, dissolve in the field of the older population but retain for some time memory of their initial structure. The difference of ages inferred through isochrones and kinematics, in this regard, could provide a powerful tool to quantify the timescale of gas removal.

Context. Detecting and characterizing substellar companions for which the luminosity, mass, and age can be determined independently is of utter importance to test and calibrate the evolutionary models due to uncertainties in their formation mechanisms. HD 19467 is a bright and nearby star hosting a cool brown dwarf companion detected with radial velocities and imaging, making it a valuable object for such studies. Aims. We aim to further characterize the orbital, spectral, and physical properties of the HD 19467 system. Methods. We present new high-contrast imaging data with the SPHERE and NaCo instruments. We also analyze archival data from the instruments HARPS, NaCo, HIRES, UVES, and ASAS. Furthermore, we use proper motion data of the star from HIPPARCOS and Gaia. Results. We refined the properties of the host star and derived an age of 8.0+2.0−1.0 Gyr based on isochrones, gyrochronology, and chemical and kinematic arguments. This age estimate is slightly younger than previous age estimates of ~9–11 Gyr based on isochrones. No orbital curvature is seen in the current imaging, radial velocity, and astrometric data. From a joint fit of the data, we refined the orbital parameters for HD 19467B, including: a period of 398+95−93 yr, an inclination of 129.8+8.1−5.1 deg, an eccentricity of 0.56 ± 0.09, a longitude of the ascending node of 134.8 ± 4.5 deg, and an argument of the periastron of 64.2+5.5−6.3 deg. We assess a dynamical mass of 74+12−9 MJ. The fit with atmospheric models of the spectrophotometric data of the companion indicates an atmosphere without clouds or with very thin clouds, an effective temperature of 1042+77−71 K, and a high surface gravity of 5.34+0.8−0.9 dex. The comparison to model predictions of the bolometric luminosity and dynamical mass of HD 19467B, assuming our system age estimate, indicates a better agreement with the Burrows et al. (1997, ApJ, 491, 856) models; whereas, the other evolutionary models used tend to underestimate its cooling rate.

The planets HR8799bc display nearly identical colours and spectra as variable young exoplanet analogues such as VHS 1256-1257ABb and PSO J318.5-22, and are likely to be similarly variable. Here we present results from a 5-epoch SPHERE IRDIS broadband-H search for variability in these two planets. HR 8799b aperture photometry and HR 8799bc negative simulated planet photometry share similar trends within uncertainties. Satellite spot lightcurves share the same trends as the planet lightcurves in the August 2018 epochs, but diverge in the October 2017 epochs. We consider Δ(mag)b − Δ(mag)c to trace non-shared variations between the two planets, and rule out non-shared variability in Δ(mag)b − Δ(mag)c to the 10-20% level over 4-5 hours. To quantify our sensitivity to variability, we simulate variable lightcurves by inserting and retrieving a suite of simulated planets at similar radii from the star as HR 8799bc, but offset in position angle. For HR 8799b, for periods <10 hours, we are sensitive to variability with amplitude $>5\%$. For HR 8799c, our sensitivity is limited to variability $>25\%$ for similar periods.