Herschel discovery of a new class of cold, faint debris discs
Journal article, 2011

We present Herschel PACS 100 and 160 mu m observations of the solar-type stars alpha Men, HD 88230 and HD 210277, which form part of the FGK stars sample of the Herschel open time key programme (OTKP) DUNES (DUst around NEarby S tars). Our observations show small infrared excesses at 160 mu m for all three stars. HD 210277 also shows a small excess at 100 mu m, while the 100 mu m fluxes of alpha Men and HD 88230 agree with the stellar photospheric predictions. We attribute these infrared excesses to a new class of cold, faint debris discs. Both alpha Men and HD 88230 are spatially resolved in the PACS 160 mu m images, while HD 210277 is point-like at that wavelength. The projected linear sizes of the extended emission lie in the range from similar to 115 to <= 250 AU. The estimated black body temperatures from the 100 and 160 mu m fluxes are less than or similar to 22 K, and the fractional luminosity of the cold dust is L(dust)/L(*) similar to 10(-6), close to the luminosity of the solar-system's Kuiper belt. These debris discs are the coldest and faintest discs discovered so far around mature stars, so they cannot be explained easily invoking "classical" debris disc models.

HD 210277 (HIP 109378)

disks

planetary systems

images

stars: individual:

(HIP 29271)

stars: individual: HD 88230 (HIP 49908)

circumstellar matter

stars: individual: alpha Men

pacs

main-sequence stars

planets

Author

C. Eiroa

Universidad Autonoma de Madrid (UAM)

J. P. Marshall

Universidad Autonoma de Madrid (UAM)

A. Mora

European Space Astronomy Centre (ESA)

A. Krivov

Friedrich Schiller University Jena

B. Montesinos

Centro de Astrobiologia (CAB)

O. Absil

University of Liège

D. R. Ardila

CalTech

M. Arevalo

Centro de Astrobiologia (CAB)

J. C. Augereau

Université Grenoble Alpes

A. Bayo

European Space Observatory

W. Danchi

NASA Goddard Space Flight Center

C. del Burgo

UNINOVA-CA3

S. Ertel

University of Kiel

M. Fridlund

ESTEC/SRE-SA

B. M. Gonzalez-Garcia

European Space Astronomy Centre (ESA)

A. Heras

ESTEC/SRE-SA

J. Lebreton

Université Grenoble Alpes

René Liseau

Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics

J. Maldonado

Universidad Autonoma de Madrid (UAM)

G. Meeus

Universidad Autonoma de Madrid (UAM)

D. Montes

Complutense University

G.L. Pilbratt

ESTEC/SRE-SA

A. Roberge

NASA Goddard Space Flight Center

J. Sanz-Forcada

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

University of Kiel

Astronomy and Astrophysics

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

Vol. 536 L4

Subject Categories

Astronomy, Astrophysics and Cosmology

DOI

10.1051/0004-6361/201117797