Reference : Coronagraphic imaging of three weak-line T Tauri stars: evidence of planetary formation ...
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Space science, astronomy & astrophysics
http://hdl.handle.net/2268/22981
Coronagraphic imaging of three weak-line T Tauri stars: evidence of planetary formation around PDS 70
English
Riaud, Pierre mailto [IAGL, Université de Liège, 17 Allée du 6 Août, 4000 Sart Tilman, Belgium]
Mawet, Dimitri [IAGL, Université de Liège, 17 Allée du 6 Août, 4000 Sart Tilman, Belgium]
Absil, Olivier mailto [Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Astroph. extragalactique et observations spatiales (AEOS) >]
Boccaletti, A. [LESIA, Observatoire de Paris-Meudon, 5 pl. Jules Janssen, 92195 Meudon, France]
Baudoz, P. [LESIA, Observatoire de Paris-Meudon, 5 pl. Jules Janssen, 92195 Meudon, France]
Herwats, Emilie [Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Astroph. extragalactique et observations spatiales (AEOS) >]
Surdej, Jean mailto [Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Astroph. extragalactique et observations spatiales (AEOS) >]
Oct-2006
Astronomy and Astrophysics
EDP Sciences
458
317-325
Yes (verified by ORBi)
International
0004-6361
1432-0746
Les Ulis
France
[en] stars: circumstellar matter ; instrumentation: adaptive optics ; methods: observational ; stars: planetary systems: protoplanetary disks
[en] Context: High angular resolution imaging of nearby pre-main sequence stars with ages between 1 and 30 Myr can give valuable information on planet formation mechanisms. This range of ages is thought to correspond to the dissipation of the optically thick dust disks surrounding young stars and to the end of the planet formation. Aims: This paper presents new observations of three weak-line T Tauri Stars (WTTS) of intermediate ages ranging from 7 to 16 Myr. It aims at increasing the knowledge and sample of circumstellar disks around "old" WTTS. Methods: We observed three stars with the VLT's NAOS-CONICA adaptive optics system in coronagraphic mode. The four-quadrant phase mask coronagraph was used to improve the dynamic range (by a factor of 100) while preserving the high angular resolution (inner working angle of 0farcs 15). Results: One object of our sample (PDS 70), a K5 star, exhibits a brown dwarf companion and a disk in scattered light with a surface brightness power law of r[SUP]-2.8[/SUP], extending from a distance of 14 to 140 AU (assuming a stellar distance of 140 pc) and an integrated luminosity of 16.7 mJy in the K_s-band. The mass of the companion can be estimated to be within a range between 27 and 50 Jupiter masses with an effective temperature of 2750 ± 100 K. This object also shows a resolved outflow stretching up to 550 AU. Conclusions: This newly detected circumstellar disk shows strong similarities with the disk around TW Hya, and adds to the observed population of "old" TTS surrounded by circumstellar material. Moreover, three clues of planetary formation are brought to light by this study.
Researchers
http://hdl.handle.net/2268/22981
also: http://hdl.handle.net/2268/18840
10.1051/0004-6361:20065232
http://esoads.eso.org/abs/2006A%26A...458..317R
http://www.aanda.org/index.php?option=article&access=bibcode&bibcode=2006A%2526A...458..317RFUL - Copyright ESO 2006, published by EDP Sciences.

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