Debris discs are belts of dust particles created from collisions of planetesimals (comets and asteroids) in extrasolar planetary systems. The prototype disc around Vega was discovered virgul25 years ago by IRAS, and virgul20 discs have been imaged to date, primarily by HST, SCUBA and Spitzer. Despite the relatively low numbers, debris discs are seen to be extraordinarily diverse in character, including systems with vast populations of comets or with perturbations by planets at tens of AU from the host star. Due to this low number, however, our knowledge of debris discs is incomplete; there has been no unbiased survey specifically designed to image a large number of discs. Spitzer greatly improved our understanding of the disc-rich A stars but the number of detections is still low for solar-analogue FGK stars and especially the numerous M stars. For Herschel, we therefore propose the DEBRIS (..Disc Emission via a Bias-free Reconnaissance in the Infrared-Submillimetre) Key Project which will probe 450 nearby A-M stellar systems for debris and measure Solar System dust levels in debris discs for the first time. The large sample is statistically robust and without bias, providing a rich legacy for debris disc and exo-planet science. This deep, flux-limited survey will obtain PACS 100-160 images of all 450 systems (472 fields due to wide binaries), and it will be possible to resolve discs toward each one with the PACS. high resolution. DEBRIS includes SPIRE imaging in systems where debris is detected with PACS (a rate of 50% is expected). The key science questions are: (a) which kinds of stars have debris and why? (b) what are the sizes, temperatures and masses of the debris discs? (c) what is the relation of resolved disc structures to the exo-planets? and (d) is our Kuiper Belt common or unusual? The Herschel DEBRIS Key Project will answer these questions using Herschel.s high sensitivity, spectral coverage and resolut...ion. Our team includes world experts in debris discs and exo-planet science from 8 countries.
Publication
VLT-SPHERE Multiwavelength High-contrast Imaging of the HD 115600 Debris Disk: New Constraints on the Dust Geometry and the Presence of Young Giant Planets . Gibbs Aidan et al. . The Astronomical Journal, Volume 157, Issue 1, article id. 39, 11 pp. (2019). . 157 . 10.3847/1538-3881/aaf1bd . 2019AJ....157...39G , The dust grain size-stellar luminosity trend in debris discs . Pawellek Nicole et al. . Monthly Notices of the Royal Astronomical Society, Volume 454, Issue 3, p.3207-3221 . 454 . 10.1093/mnras/stv2142 . 2015MNRAS.454.3207P , Stellar multiplicity and debris discs: an unbiased sample . Rodriguez David R. et al. . Monthly Notices of the Royal Astronomical Society, Volume 449, Issue 3, p.3160-3170 . 449 . 10.1093/mnras/stv483 . 2015MNRAS.449.3160R , A-type Stellar Abundances: A Corollary to Herschel Observations of Debris Disks . Draper Zachary H. et al. . The Astrophysical Journal, Volume 857, Issue 2, article id. 93, 16 pp. (2018). . 857 . 10.3847/1538-4357/aab1fd . 2018ApJ...857...93D , Resolving debris discs in the far-infrared: Early highlights from the DEBRIS survey . Matthews B. C. et al. . Astronomy and Astrophysics, Volume 518, id.L135, 5 pp. . 518 . 10.1051/0004-6361/201014667 . 2010A&A...518L.135M , Disk Radii and Grain Sizes in Herschel-resolved Debris Disks . Pawellek Nicole et al. . The Astrophysical Journal, Volume 792, Issue 1, article id. 65, 19 pp. (2014). . 792 . 10.1088/0004-637X/792/1/65 . 2014ApJ...792...65P ,
Herschel was launched on 14 May 2009! It is the fourth 'cornerstone' mission in the ESA science programme. With a 3.5 m Cassegrain telescope it is the largest space telescope ever launched. It is performing photometry and spectroscopy in approximately the 55-671 µm range, bridging the gap between earlier infrared space missions and groundbased facilities.
