Proceedings of the International Astronomical Union

Direct Imaging of Exoplanets: Science & Techniques
Contributed Papers

PEGASE: a DARWIN/TPF pathfinder

M. Ollivier a1, J.-M. Le Duigou a2, D. Mourard a3, O. Absil a4, F. Cassaing a5, E. Herwats a4, L. Escarrat a5, B. Chazelas a1, F. Allard a6, R. Clédassou a2, V. Coudé du Foresto a7, M. Delpech a2, P. Duchon a2, P.-Y. Guidotti a2, A. Léger a1, X. Leyre a8, F. Malbet a9, D. Rouan a7 and S. Udry a10
a1 Institut d'Astrophysique Spatiale (IAS), bâtiment 121, F-91405 Orsay (France), Université Paris-Sud 11 and CNRS (UMR 8617), email:
a2 Centre National d'Etudes Spatiales - TOULOUSE
a3 Observatoire de la Côte d'Azur, Dpt GEMINI
a4 Université de Liège
a5 Office National d'Etudes et de Recherches Aéronautiques
a6 Ecole Normale Supérieure de Lyon
a7 LESIA, Observatoire de Paris
a8 Alcatel Alenia Space, CANNES
a9 Laboratoire d'Astrophysique de l'Observatoire de Grenoble
a10 Observatoire de Genève

Article author query
ollivier m   [Google Scholar] 
le duigou j   [Google Scholar] 
mourard d   [Google Scholar] 
absil o   [Google Scholar] 
cassaing f   [Google Scholar] 
herwats e   [Google Scholar] 
escarrat l   [Google Scholar] 
chazelas b   [Google Scholar] 
allard f   [Google Scholar] 
cledassou r   [Google Scholar] 
du foresto vc   [Google Scholar] 
delpech m   [Google Scholar] 
duchon p   [Google Scholar] 
guidotti p   [Google Scholar] 
leger a   [Google Scholar] 
leyre x   [Google Scholar] 
malbet f   [Google Scholar] 
rouan d   [Google Scholar] 
udry s   [Google Scholar] 
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The space mission PEGASE, proposed to the CNES (Centre National d'Etudes Spatiales = French Space Agency) in the framework of its call for scientific proposals : “formation flying missions”, is a 2-aperture interferometer, composed by 3 free flying satellites (2 siderostats and 1 beam combiner), allowing baselines from 50 to 500 m in both nulling and visibility modes. With an angular resolution of a few mas and a spectral resolution of several tens in the spectral range 2.5-5 microns, PEGASE has several goals:

  • science : spectroscopy of hot jupiters (Pegasides) and brown dwarves, exploration of the inner part of protoplanetary disks
  • technology : validation in real space conditions of formation flying, nulling and visibility interferometry concepts.
PEGASE has been studied at a 0-level. In this paper, we summarize the scientific program and associated technological and mission trade-off coming from this 0-level study. We also discuss how PEGASE can be considered as a TPF/DARWIN pathfinder in an international roadmap towards more complex space interferometry missions such as DARWIN/TPF.

Key Words: Interferometry; Formation flying; Spectroscopy of low mass objects; Protoplanetary disks.