Dust Around NEarby Stars. The survey observational results

Debris discs are a consequence of the planet formation process and constitute the fingerprints of planetesimal systems. Their solar system’s counterparts are the asteroid and Edgeworth-Kuiper belts. The DUNES (Dust Around NEarby Stars, Herschel Open Time Key Program) survey aims at detecting extra-solar analogues to the Edgeworth-Kuiper belt around solar-type stars, putting in this way the solar system into context. The survey allows us to address some questions related to the prevalence and properties of planetesimal systems.
We used Herschel/PACS to observe a sample of nearby FGK stars. Data at 100 and 160 μm were obtained, complemented in some cases with observations at 70 μm, and at 250, 350 and 500 μm using SPIRE. The observing strategy was to integrate as deep as possible at 100 μm to detect the stellar photosphere.
The survey’s objectives have been accomplished. Debris discs with fractional luminosities, black body radii and temperatures in the range of the Edgeworth-Kuiper belt have been detected. The incidence rate of discs around the DUNES stars is increased from a rate of ∼ 12.1% ± 5% before Herschel to ∼ 20.2% ± 2%. A significant fraction (52%) of the discs are resolved, which represents an enormous step ahead from the previously known resolved discs. Some stars are associated with faint far-IR excesses attributed to a new class of cold discs. Although it cannot be excluded that these excesses are produced by coincidental alignment of background galaxies, statistical arguments suggest that at least some of them are true debris discs. Some discs display peculiar SEDs with spectral indexes in the 70–160 μm range steeper than the Rayleigh-Jeans one. An analysis of the debris disc parameters suggests that a decrease might exist of the mean black body radius from the F-type to the K-type stars. In addition, a weak trend is suggested for a correlation of disc sizes and an anticorrelation of disc temperatures with the stellar age.

The following mosaic has been constructed with the Herschel/PACS 100 micron data. Clicking on any individual image will lead you to a more detail description of that particular source.

HIP10138 HIP101955 HIP101997 HIP103389 HIP104214 HIP104217 HIP105312
HIP106696 HIP107350 HIP107649 HIP10798 HIP108870 HIP109378 HIP109422
HIP110109 HIP113357 HIP113576 HIP11452 HIP114948 HIP116745 HIP11964
HIP120005 HIP12777 HIP13402 HIP14954 HIP15330 HIP15371 HIP15799
HIP16134 HIP171 HIP17420 HIP17439 HIP19849 HIP19884 HIP22263
HIP23311 HIP25110 HIP27887 HIP28103 HIP28442 HIP29271 HIP2941
HIP29568 HIP3093 HIP32439 HIP32480 HIP33277 HIP34017 HIP34065
HIP3497 HIP35136 HIP36439 HIP3821 HIP38382 HIP38784 HIP3909
HIP40693 HIP40843 HIP4148 HIP42430 HIP42438 HIP43587 HIP43726
HIP44897 HIP45333 HIP45617 HIP46580 HIP47592 HIP49081 HIP49908
HIP51459 HIP51502 HIP53721 HIP544 HIP54646 HIP56452 HIP57507
HIP57939 HIP58345 HIP62145 HIP62207 HIP62523 HIP64792 HIP64797
HIP65026 HIP65721 HIP67275 HIP67422 HIP67620 HIP68184 HIP68682
HIP69965 HIP70319 HIP70857 HIP71181 HIP71681 HIP71683 HIP71908
HIP72567 HIP72603 HIP72848 HIP73100 HIP73182 HIP73184 HIP73996
HIP7513 HIP77052 HIP78459 HIP78775 HIP79248 HIP7978 HIP80725
HIP82860 HIP83389 HIP84862 HIP85235 HIP85295 HIP86036 HIP86796
HIP8768 HIP88601 HIP88972 HIP89042 HIP91009 HIP910 HIP92043
HIP95995 HIP96100 HIP96441 HIP97944 HIP98959 HIP99240 HIP99461