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Séminaire du Jeudi 7 janvier 2016

Radii, masses and ages of 18 bright stars using interferometry and new estimations of exoplabetary parameters

Roxanne Ligi (LAM)
Thursday January 7th - 11am
IPAG Seminar Room - IPAG

Accurate stellar parameters are needed in numerous domains of astrophysics. In particular, stellar parameters are required elements for studying exoplanetary systems, including their story. I will present the results of an interferometric survey of 18 bright exoplanet host and potential host stars using the VEGA/CHARA interferometer operating in the visible domain. We measured their angular diameters and combined them with their distance to get their radius. We used photometry to derive their bolometric flux and, then, their effective temperature and luminosity to place them on the H-R diagram. We then used the PARSEC models to derive their best fit ages and masses, with error bars derived from Monte Carlo calculations. From these stellar parameters and RV measurements, we provide new estimates of semi-major axes and minimum masses of exoplanets with reliable uncertainties, along with the new stellar habitable zones. We paid particular attention to the 55 Cnc system, for which we brought new estimations of the radius and mass of the transiting exoplanet it hosts, 55 Cnc e. We could also derive its density and confirm that it is an Earth-like planet.

PDF - 5.5 Mo

Sous la tutelle de:


Sous la tutelle de:

CNRS Université Grenoble Alpes