Resolving the cold debris disc around a planet-hosting star. PACS photometric imaging observations of q1 Eridani (HD 10647, HR 506)
Journal article, 2010
Context. About two dozen exo-solar debris systems have been spatially resolved. These debris discs commonly display a variety of structural features such as clumps, rings, belts, excentric distributions and spiral patterns. In most cases, these features are believed to be formed, shaped and maintained by the dynamical influence of planets orbiting the host stars. In very few cases has the presence of the dynamically important planet(s) been inferred from direct observation. Aims. The solar-type star q(1) Eri is known to be surrounded by debris, extended on scales of less than or similar to 30 ''. The star is also known to host at least one planet, albeit on an orbit far too small to make it responsible for structures at distances of tens to hundreds of AU. The aim of the present investigation is twofold: to determine the optical and material properties of the debris and to infer the spatial distribution of the dust, which may hint at the presence of additional planets. Methods. The Photodetector Array Camera and Spectrometer (PACS) aboard the Herschel Space Observatory allows imaging observations in the far infrared at unprecedented resolution, i.e. at better than 6 '' to 12 '' over the wavelength range of 60 mu m to 210 mu m. Together with the results from ground-based observations, these spatially resolved data can be modelled to determine the nature of the debris and its evolution more reliably than what would be possible from unresolved data alone. Results. For the first time has the q(1) Eri disc been resolved at far infrared wavelengths. The PACS observations at 70 mu m, 100 mu m and 160 mu m reveal an oval image showing a disc-like structure in all bands, the size of which increases with wavelength. Assuming a circular shape yields the inclination of its equatorial plane with respect to that of the sky, i > 53 degrees. The results of image de-convolution indicate that i likely is larger than 63 degrees, where 90 degrees corresponds to an edge-on disc. Conclusions. The observed emission is thermal and optically thin. The resolved data are consistent with debris at temperatures below 30 K at radii larger than 120 AU. From image de-convolution, we find that q(1) Eri is surrounded by an about 40 AU wide ring at the radial distance of similar to 85 AU. This is the first real Edgeworth-Kuiper Belt analogue ever observed.
circumstellar matter
stars: individual: q(1) Eri (HD 10647
belt
planetary
spitzer
HR 506
hst
stars: formation
HIP 7978)
systems
Author
René Liseau
Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics
C. Eiroa
Universidad Autonoma de Madrid (UAM)
D. Fedele
Universidad Autonoma de Madrid (UAM)
Max Planck Society
Johns Hopkins University
J. C. Augereau
Grenoble Alpes University
G. Olofsson
AlbaNova University Center
B. Gonzalez
European Space Astronomy Centre (ESAC)
J. Maldonado
Universidad Autonoma de Madrid (UAM)
B. Montesinos
Centro de Astrobiologia (CAB)
A. Mora
Universidad Autonoma de Madrid (UAM)
European Space Astronomy Centre (ESAC)
O. Absil
University of Liège
D. R. Ardila
Spitzer Science Center
D. Barrado
California Institute of Technology (Caltech)
Calar Alto Astronomical Observatory
Centro de Astrobiologia (CAB)
A. Bayo
Centro de Astrobiologia (CAB)
European Southern Observatory Santiago
C. Beichman
UNINOVA-CA3
G. Bryden
California Institute of Technology (Caltech)
W. Danchi
National Aeronautics and Space Administration (NASA)
C. del Burgo
UNINOVA-CA3
S. Ertel
University of Kiel
Malcolm Fridlund
European Space Research and Technology Centre (ESA ESTEC)
A. Heras
European Space Research and Technology Centre (ESA ESTEC)
A. Krivov
Friedrich Schiller University Jena
R. Launhardt
Max Planck Society
J. Lebreton
Grenoble Alpes University
T. Lohne
Friedrich Schiller University Jena
J. P. Marshall
Open University
G. Meeus
Universidad Autonoma de Madrid (UAM)
S. Muller
Friedrich Schiller University Jena
G.L. Pilbratt
European Space Research and Technology Centre (ESA ESTEC)
A. Roberge
UNINOVA-CA3
J. Rodmann
Materials Space Evaluation and Radiation Effects Section
E. Solano
Centro de Astrobiologia (CAB)
K. R. Stapelfeldt
California Institute of Technology (Caltech)
P. Thebault
Observatoire de Paris-Meudon
G. J. White
Open University
STFC Rutherford Appleton Laboratory
S. Wolf
University of Kiel
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 518 Article Number: L132 L132Subject Categories (SSIF 2011)
Astronomy, Astrophysics and Cosmology
DOI
10.1051/0004-6361/201014601