Free access
Astron. Astrophys. Suppl. Ser.
Volume 134, Number 3, February I 1999
Page(s) 553 - 560
DOI: 10.1051/aas:1999148

Astron. Astrophys. Suppl. Ser. 134, 553-560

On the detection of satellites of extrasolar planets with the method of transits

P. Sartoretti1 - J. Schneider2

Send offprint request: P. Sartoretti

1 - Institut d'Astrophysique de Paris, 98 bis boulevard Arago, 75014 Paris, France
2 - DARC, Observatoire de Meudon, Place Jules Janssen, 92195 Meudon, France

Received March 27; accepted September 9, 1998


We compute the detection probability of satellites of extrasolar planets with the method of transits, under the assumption that the duration of the observations is at least as long as the planet orbital period. We separate the cases when the parent planet does and does not also transit over the star. The possible satellites are assumed to have orbital radii between the Roche limit and the Hill radius. We find that if a satellite is extended enough to produce a detectable drop in the stellar lightcurve, the probability to detect it when the planet also transits over the star is nearly unity. If the planet does not transit, the probability to detect a Jupiter-like or terrestrial satellite is modest, but it can be comparable to that of detecting a planet if the satellite orbital radius is large. If a satellite is not extended enough to produce a detectable drop in the stellar lightcurve during a transit, it might still be detected through the time shift of planetary transits resulting from the rotation of the planet around the barycenter of the planet-satellite system.

Key words: planets and satellites: general -- stars: planetary systems -- techniques: photometric

Copyright The European Southern Observatory (ESO)

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 You should disable this module if you wish to use the OpenURL server that you or your library have defined.