First astronomical unit scale image of the GW Orionis triple system Direct detection of a new stellar companion

被引：19

作者：

Berger, J. -P. ^{[1
,2
]}

Monnier, J. D. ^{[3
]}

Millan-Gabet, R. ^{[4
]}

Renard, S. ^{[2
]}

Pedretti, E. ^{[5
]}

Traub, W. ^{[6
]}

Bechet, C. ^{[13
]}

Benisty, M. ^{[7
]}

Carleton, N. ^{[8
]}

Haguenauer, P. ^{[1
]}

Kern, P. ^{[2
]}

Labeye, P. ^{[9
]}

Longa, F. ^{[2
]}

Lacasse, M. ^{[8
]}

Malbet, F. ^{[2
]}

Perraut, K. ^{[2
]}

Ragland, S. ^{[10
]}

Schloerb, P. ^{[11
]}

Schuller, P. A. ^{[12
]}

Thiebaut, E. ^{[13
]}

机构：

[1] European So Observ, Santiago 19, Chile

[2] Univ Grenoble 1, IPAG, CNRS UMR 5571, F-38041 Grenoble, France

[3] Univ Michigan, Ann Arbor, MI 48109 USA

[4] CALTECH, Pasadena, CA 91125 USA

[5] Univ St Andrews, St Andrews KY16 9AJ, Fife, Scotland

[6] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA

[7] INAF Osservatorio Astrofis Arcetri, I-50125 Florence, Italy

[8] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA

[9] CEA DRT LETI, F-38054 Grenoble, France

[10] WM Keck Observ, Kamuela, HI 96743 USA

[11] Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA

[12] Univ Paris 11, CNRS UMR 8617, IAS, F-91405 Orsay, France

[13] CRAL Observ Lyon, F-69561 St Genis Laval, France

来源：

ASTRONOMY & ASTROPHYSICS | 2011年 / 529卷

关键词：

binaries: general; stars: variables: T Tauri; Herbig Ae/Be; accretion; accretion disks; techniques: interferometric; INTERFEROMETRY; ACCRETION; EVOLUTION; DISTANCE; NEBULA; TRACKS; STARS; IOTA;

D O I：

10.1051/0004-6361/201016219

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Context. Young and close multiple systems are unique laboratories to probe the initial dynamical interactions between forming stellar systems and their dust and gas environment. Their study is a key building block to understanding the high frequency of main-sequence multiple systems. However, the number of detected spectroscopic young multiple systems that allow dynamical studies is limited. GW Orionis is one such system. It is one of the brightest young T Tauri stars and is surrounded by a massive disk. Aims. Our goal is to probe the GW Orionis multiplicity at angular scales at which we can spatially resolve the orbit. Methods. We used the IOTA/IONIC3 interferometer to probe the environment of GW Orionis with an astronomical unit resolution in 2003, 2004, and 2005. By measuring squared visibilities and closure phases with a good UV coverage we carry out the first image reconstruction of GW Ori from infrared long-baseline interferometry. Results. We obtained the first infrared image of a T Tauri multiple system with astronomical unit resolution. We show that GW Orionis is a triple system, resolve for the first time the previously known inner pair (separation rho similar to 1.4 AU) and reveal a new more distant component (GW Ori C) with a projected separation of similar to 8 AU with direct evidence of motion. Furthermore, the nearly equal (2: 1) H-band flux ratio of the inner components suggests that either GW Ori B is undergoing a preferential accretion event that increases its disk luminosity or that the estimate of the masses has to be revisited in favour of a more equal mass-ratio system that is seen at lower inclination. Conclusions. Accretion disk models of GW Ori will need to be completely reconsidered because of this outer companion C and the unexpected brightness of companion B.

引用

页数：4