Description
Astrometry and direct imaging techniques are the only self-consistent ones as they provide the complete orbital configuration and masses of the system. Only a few planetary systems have been found to date using these techniques, but they are among some of the most interesting ones (long period orbits and young systems). Moreover, the situation is about to change drastically. The GAIA data release #4 (expected for 2026) will provide the full astrometric orbital solution of thousands of exoplanets, which is very timely for the DDE meeting.
Absolute astrometry and direct imaging enable the detection of (mostly) giant planets located beyond 5–10 AU – distances typically inaccessible to transit photometry and radial velocity methods. As such, they play a crucial role in probing the population of distant giant planets and testing models of planet formation. The youngest of these planets also provide unique opportunities to study...
Astrometric detections of exoplanets by missions like Gaia and JASMINE rely on measuring minute changes in the positions of stars - known as astrometric jitter - arising from the gravitational pull of the planetary companions. Another source of astrometric jitter is stellar magnetic activity which can interfere with the detection and characterization of Earth-mass planets through astrometric...
I wish to present a new tool called GaiaPMEX, introduced in two recent papers (Kiefer et al. 2024 a, b). It characterizes the mass and semi-major axis relative to the central star (sma) of any possible companion around any source observed with Gaia. It uses for the first time the value of RUWE published in the DR3 archives, and when available, combines it with the Gaia-Hipparcos proper motion...
HR8799 is a young multi-planet system that uniquely hosts four super-Jupiter planets and has been well-monitored through imaging and spectroscopy observations. This is the only directly imaged system for which we observe more than two exoplanets-- presenting a unique study of planet-planet interactions through astrometric measurements of high enough precision. Through the continued monitoring...
M-type stars, the most common in the universe, are a major focus for surveys because they are well-suited for detecting low-mass planets in the habitable zone. Despite their importance in the formation and evolution of low-mass planets, little is known about giant planets (GPs) in M star systems. Detecting long period GPs (with semi-major axis typically greater than 1 au) is difficult with...
The relation between the inner and outer regions of exoplanetary systems is still an open question, for example considering that recent studies are still presenting conflicting results on the relationship between short-period small planets and cold Jupiters. One of the key obstacles to solving this issue is that the most prolific detection techniques so far are strongly biased towards...
Hot- and cold-start planet formation models predict differing luminosities for the young, bright planets that direct imaging surveys are most sensitive to. However, precise mass estimates are required to distinguish between these models observationally. The presence of two directly imaged planets, PDS 70 b and c, in the PDS 70 protoplanetary disk provides us a unique opportunity for dynamical...
Analogues to the giant planets in our solar system are difficult to detect in the exoplanet context with our current observational methods. However, with new missions based on astrometry, these planets will become a prime population to study. The release of the Gaia DR4 catalogue in 2026, detecting ~1,000-10,000 giant planets at large orbital separations, will provide the first demographic...
With the ever-growing population of detected exoplanets, the startling variety in planetary configurations remains mostly unexplained. Studying planet formation in young stellar systems is a crucial step in order to truly understand this great diversity in observed exoplanets. To this end, the search for protoplanets is crucial; however, only two of them have been robustly confirmed so far,...
Blind direct imaging (DI) surveys carried-on with state-of-the-art high-contrast imaging instruments allow to detect just a low number of new planetary mass companions due to the paucity of such objects at the typical separations explored by such instruments. The possibility to couple DI with other techniques (e.g., astrometry and RV) allows to select targets with an high probability to host a...
The Keck Planet Imager and Characterizer (KPIC) is a high contrast imaging suite that feeds a high resolution spectrograph (1.9-2.5 microns, R~35,000) at the W.M. Keck Observatory. One target accessible with KPIC is GQ Lup B, a substellar companion with a detected circumplanetary disk, or CPD. Observations of the CPD suggest the presence of a cavity, possibly formed by an exo-satellite. Using...
