Herscheldiscovery of a new class of cold, faint debris discs
Open Access
- 6 December 2011
- journal article
- research article
- Published by EDP Sciences in Astronomy & Astrophysics
- Vol. 536, L4
- https://doi.org/10.1051/0004-6361/201117797
Abstract
We present Herschel PACS 100 and 160 μm observations of the solar-type stars α 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 Stars). Our observations show small infrared excesses at 160 μm for all three stars. HD 210277 also shows a small excess at 100 μm, while the 100 μm fluxes of α 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 α Men and HD 88230 are spatially resolved in the PACS 160 μm images, while HD 210277 is point-like at that wavelength. The projected linear sizes of the extended emission lie in the range from ~115 to ≤ 250 AU. The estimated black body temperatures from the 100 and 160 μm fluxes are ≲22 K, and the fractional luminosity of the cold dust is L dust/L ⋆ ~ 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.Keywords
This publication has 21 references indexed in Scilit:
- New insights on ices in Centaur and Transneptunian populationsIcarus, 2011
- Dissecting the cosmic infra-red background withHerschel/PEPAstronomy & Astrophysics, 2010
- Cold DUst around NEarby Stars (DUNES). First resultsAstronomy & Astrophysics, 2010
- FOMALHAUT'S DEBRIS DISK AND PLANET: CONSTRAINING THE MASS OF FOMALHAUT B FROM DISK MORPHOLOGYThe Astrophysical Journal, 2009
- Variations on Debris Disks: Icy Planet Formation at 30–150 AU for 1–3M⊙Main‐Sequence StarsThe Astrophysical Journal Supplement Series, 2008
- Optical Images of an Exosolar Planet 25 Light-Years from EarthScience, 2008
- New Debris Disks around Nearby Main‐Sequence Stars: Impact on the Direct Detection of PlanetsThe Astrophysical Journal, 2006
- Circumstellar material in the Vega inner system revealed by CHARA/FLUORAstronomy & Astrophysics, 2006
- Drizzle: A Method for the Linear Reconstruction of Undersampled ImagesPublications of the Astronomical Society of the Pacific, 2002
- Discovery of a shell around Alpha LyraeThe Astrophysical Journal, 1984