Dynamics of the young multiple system GG Tauri.

H. Beust (1) , Anne Dutrey (2, 3, 4)

1 LAOG - Laboratoire d'Astrophysique de Grenoble
2 L3AB - Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux
3 OASU - Observatoire aquitain des sciences de l'univers
4 LAB - Laboratoire d'Astrophysique de Bordeaux [Pessac]

The GG Tauri system is a prototype example of a young, pre-main sequence multiple stellar system. Both millimeter and optical observations reveal that the central binary (GG Tau A) harbors a ring-shape circumbinary disk. In this paper, we analyse a compilation of astrometric data of the GG Tau A binary over 12 years that allow us, in combination with information coming from the disk observations (millimeter data), to derive a fairly accurate fit of the orbit (a=32.4 AU, e=0.34). We also perform a dynamical study of the circumbinary disk, and show that in order to be in agreement with the orbit deduced from the fit, the inner gap of the disk should be approximatively twice as small as observed. We show that if we allow the error bars on the astrometric data to be larger, another orbit may be found (a=62 AU, e=0.35), compatible with the location of the inner disk gap, although only marginally compatible with the astrometric data. Possible solutions to solve this discrepancy are discussed.

Mots clés: planetary systems: protoplanetary disks; stars: individual: GG Tau; methods: numerical; celestial mechanics; stars: circumstellar matter

Domaines: Astrophysique galactique [astro-ph.GA]

H. Beust, Anne Dutrey. Dynamics of the young multiple system GG Tauri.: I. Orbital fits and inner edge of the circumbinary disk of GG Tau A. Astronomy and Astrophysics - A&A, 2005, 439 (2), pp.585-594. ⟨10.1051/0004-6361:20042441⟩. ⟨hal-00417586⟩