Resolving the cold debris disc around a planet-hosting star. PACS photometric imaging observations of q1 Eridani (HD 10647, HR 506)
Artikel i vetenskaplig tidskrift, 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.

hst

HR 506

systems

planetary

belt

stars: formation

circumstellar matter

spitzer

stars: individual: q(1) Eri (HD 10647

HIP 7978)

Författare

René Liseau

Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik

C. Eiroa

Universidad Autonoma de Madrid (UAM)

D. Fedele

Johns Hopkins University

Universidad Autonoma de Madrid (UAM)

Max Planck-institutet

J. C. Augereau

Université Grenoble Alpes

G. Olofsson

AlbaNova University Center

B. Gonzalez

European Space Astronomy Centre (ESA)

J. Maldonado

Universidad Autonoma de Madrid (UAM)

B. Montesinos

Centro de Astrobiologia (CAB)

A. Mora

European Space Astronomy Centre (ESA)

Universidad Autonoma de Madrid (UAM)

O. Absil

Universite de Liège

D. R. Ardila

Spitzer Science Center

D. Barrado

Calar Alto Astronomical Observatory

Centro de Astrobiologia (CAB)

CalTech

A. Bayo

Centro de Astrobiologia (CAB)

European Southern Observatory Santiago

C. Beichman

UNINOVA-CA3

G. Bryden

Jet Propulsion Laboratory, California Institute of Technology

W. Danchi

NASA Goddard Space Flight Center

C. del Burgo

UNINOVA-CA3

S. Ertel

Christian-Albrechts-Universität zu Kiel

C. W. M. Fridlund

ESTEC/SRE-SA

A. Heras

ESTEC/SRE-SA

A. Krivov

Friedrich-Schiller-Universität Jena

R. Launhardt

Max Planck-institutet

J. Lebreton

Université Grenoble Alpes

T. Lohne

Friedrich-Schiller-Universität Jena

J. P. Marshall

Open University

G. Meeus

Universidad Autonoma de Madrid (UAM)

S. Muller

Friedrich-Schiller-Universität Jena

G.L. Pilbratt

ESTEC/SRE-SA

A. Roberge

UNINOVA-CA3

J. Rodmann

Materials Space Evaluation and Radiation Effects Section

E. Solano

Centro de Astrobiologia (CAB)

K. R. Stapelfeldt

Jet Propulsion Laboratory, California Institute of Technology

P. Thebault

GEPI - Galaxies, Etoiles, Physique, Instrumentation

G. J. White

Rutherford Appleton Laboratory

Open University

S. Wolf

Christian-Albrechts-Universität zu Kiel

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 518 Article Number: L132 L132

Ämneskategorier

Astronomi, astrofysik och kosmologi

DOI

10.1051/0004-6361/201014601