EDP Sciences
Free access
Issue A&A
Volume 431, Number 1, February III 2005
Page(s) 175 - 182
Section Interstellar and circumstellar matter
DOI http://dx.doi.org/10.1051/0004-6361:20041490

A&A 431, 175-182 (2005)
DOI: 10.1051/0004-6361:20041490

Mid-IR observations of circumstellar disks

II. Vega-type stars and a post-main sequence object
O. Schütz1, G. Meeus2 and M. F. Sterzik3

1  Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
    e-mail: schuetz@mpia.de
2  Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany
3  European Southern Observatory, Alonso de Cordova 3107, Santiago 19, Chile

(Received 18 June 2004 / Accepted 10 September 2004 )

We present spectral energy distributions and new N-band photometry and spectroscopy for a sample of six main sequence stars and one post-MS object using the ESO TIMMI2 camera at La Silla observatory (Chile). All objects are thought to possess circumstellar material and for the majority of the targets this is their first N-band spectroscopic observation. The emission spectra (observed in three cases), modelled with a mixture of silicates consisting of different grain sizes and composition, confirm the suspected presence of disks around these targets. The most important discovery is that HD 113766, a young Vega-type star, is host to highly processed dust which is probably second generation. It is the first time a Vega-type star with such highly evolved dust has been observed. Silicate emission of basically unevolved dust is seen in case of the post-MS object HD 41511 and the Vega-type star HD 172555. In addition, to study the cold dust, we observed a subsample at 1200  $\mu$m with the bolometer array SIMBA at the SEST in La Silla but we only got upper limits for those five objects. This shows that these Vega-type stars have a smaller amount of dust than their precursors, the T Tauri and Herbig Ae/Be stars.

Key words: stars: circumstellar matter -- stars: planetary systems: protoplanetary disks -- infrared: stars -- techniques: spectroscopic -- submillimeter

SIMBAD Objects

© ESO 2005

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.
  • If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
  • You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
  • You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.

Editor-in-Chief: T. Forveille
Letters Editor-in-Chief: J. Alves
Managing Editor: N. Aghanim

ISSN: 0004-6361 ; e-ISSN: 1432-0746
Frequency: 12 volumes per year
Published by: EDP Sciences

Mirror sites: CDS | EDP Sciences
  RSS feeds
© The European Southern Observatory (ESO)