SETI bioastro: Can stellar wobble in triple systems mimic a planet?

• Previous message: LARRY KLAES: "SETI bioastro: Oxygen abundances in planet-harbouring stars. Comparison of different abundance"

astro-ph/0509331 [abs, ps, pdf, other] :

Title: Can stellar wobble in triple systems mimic a planet?

Authors: J. Schneider, J. Cabrera

Comments: 6 pages, 5 figures

The first extrasolar planets have been detected by the measurement of the
wobble of the parent star. This wobble leads to the periodic modulation of
three observables: the radial velocity, the position on the sky and the time
of arrival of periodic signals. We show that the same wobble, and therefore
the same modulation of the three observables, can be due to the presence of
a more distant binary stellar companion. Thus, the observation of the wobble
does not, by itself, constitute a proof of a planet detection. In
particular, astrometric confirmation of a wobble does not necessarily
provide a sufficient proof of the existence of a planet candidate detected
by radial velocity. Additional conditions, which we discuss here, must be
fulfilled. We investigate the observed wobble for the planet candidates
already detected and we find that, for each case, a wobble due to a binary
stellar companion can be excluded. But for apparent Saturn-like planets in
wide orbits, there may be an ambiguity in future detections, especially in
spaceborne astrometric missions. We conclude that, in some cases, a
definitive proof for the presence of a planet requires further observations
such as direct imaging.

http://arxiv.org/abs/astro-ph/0509331

• Previous message: LARRY KLAES: "SETI bioastro: Oxygen abundances in planet-harbouring stars. Comparison of different abundance"

This archive was generated by hypermail 2.1.6 : Wed Sep 14 2005 - 15:57:50 UTC