Dans la même rubrique :
A new Nova eruption followed by AMBER on the VLTI
AMBER second commissioning (15-26 Oct 2004)
First results of AMBER stability tests (20 March 2004)
First images obtained with AMBER
AMBER has been commissionned with pair and triplet of 8m telescopes
Fringes alignment complete (16 March 2004)
AMBER scrutinizes the inner region of the young star MWC 147
Is AMBER observing the formation of a planet ?
Fuel for the black hole
On the trail of a disk around a star
The spin-orbit alignment of the Fomalhaut planetary system probed by AMBER
14 avril 2009
- Spectro-astrometric positions of Fomalhaut with AMBER.
- AMBER spectro-astrometric positions in the continuum (a) and across the Brackett gamma absorption line (b). Colors refer to the wavelength bin. The signature of the rotating photosphere (c) is clearly detected and is compared to the debris disk and the planetary companion (d) imaged in the visible by Kalas et al. (2008).
Using the combination of spectral resolution and spatial resolution provided by the instrument AMBER on the VLTI, a European team led by J.-B. Le Bouquin from ESO has been able to obtain precise spectro-astrometric measurements across the Brackett gamma absorption line of the Fomalhaut stellar system. The achieved astrometric accuracy of 3 nano-arcsecond and the spectral resolution R=1500 from the AMBER/VLTI instrument allowed them to spatially and spectrally resolve the rotating photosphere. They found a position angle 65 +/- 3 degrees for the stellar rotation axis, perfectly perpendicular with the literature measurement for the disk position angle. This is the first time such test can be performed for a debris disk, and in a non-eclipsing system. Their observations validate the standard scenario for star and planet formation, in which the angular momentum of the planetary systems are expected to be collinear with the stellar spins.
The spin-orbit alignment of the Fomalhaut planetary system probed by optical long baseline interferometry
J.-B. LeBouquin, O. Absil, M. Benisty, F. Massi, A. Mérand, and S. Steﬂ 2009, A&A in press (astro-ph/0904.1688)