Séminaire Doctoral / Seminar PhD |
| « The mass measurement of radial-velocity brown dwarves and planets » |
|
Flavien Kiefer |
| Mass is one of the most important parameters for determining the true nature of an astronomical object. Yet, many published exoplanets detected thanks to radial velocity (RV) variations of their host star still lack a measurement of their true mass. For those, only the minimum mass, or m sin(i), is known, owing to the insensitivity of RVs to the inclination of the detected orbit compared to the plane-of-the-sky. The derived mass is generally that of an assumed edge-on system (90 degrees). But many other inclinations are likely, even extreme values closer to 0 degree (face-on configuration). In such case, the mass of the companion could be strongly underestimated, possibly up to few orders of magnitude. Using high-precision astrometry can help dissipate this indetermination. In a few months now, the exquisite precision of the astrometric telescope Gaia will allow directly detecting exoplanets through astrometry, something never yet achieved. In this talk, I will show how already published Gaia data, although still incomplete, can be used to constrain the mass of exoplanetary and brown-dwarf candidates. |
|
vendredi 25 février 2022 - 15:00 Salle des séminaires Évry Schatzman, Institut d'Astrophysique |
| Page web du séminaire / Seminar's webpage |