Bibcode
Doyle, L. R.; Jenkins, J. M.; Deeg, H.-J.; Martin, E.; Schneider, J.; Chevreton, M.; Paleologou, E.; Kylafis, N.; Lee, W.-B.; Kim, H.-I.; Dunham, E.; Blue, E.; Toublanc, D.
Referencia bibliográfica
American Astronomical Society, 187th AAS Meeting, #70.18; Bulletin of the American Astronomical Society, Vol. 27, p.1382
Fecha de publicación:
12
1995
Número de citas
0
Número de citas referidas
0
Descripción
We present preliminary results from the ongoing ground-based photometric
observing program of the TEP (Transit of Extrasolar Planets) network to
detect planets in orbit around eclipsing binary stars. Observing
eclipsing binaries overcomes the statistical improbability of planetary
transits as the planetary orbital plane may be expected to be parallel
with the binary orbital plane due to precessionally induced damping
(Schneider and Doyle 1995). Observing the smallest such systems assists
in overcoming the atmospheric scintillation limits on photometric
detection. (We are presently observing the CM Draconis system whose
equivalent stellar area is only 12% that of a solar-type star, allowing
direct detections of transiting planets an order of magnitude smaller in
area than could be detected around solar-type stars.) Significant
improvement in the detectability,- well below the rms noise,- is also
achieved by cross-correlating the observational light curves with models
of all possible planetary transit configurations (a matched-filter
signal detection algorithm). In this approach the expected
quasi-periodic transit signals are ``co-added" to obtain a high
cumulative signal-to-noise ratio (SNR) from the low SNR individual
points. As an example, with moderately good photometry (~ 0.7%) using
0.9-meter ground-based telescopes, this technique should allow the
detection of 87% of all >= 2-Earth-radii planets with periods of 60
days or less at the 99.9% confidence level (i.e. 0.001 chance of a false
alarm) within a 6-month observational period (Jenkins et al.1995). On
the other hand, giant outer planets may also be photometrically detected
without having to await a transit. A small eclipsing binary system will
be significantly displaced about a binary / planet barycenter if a giant
(i.e. jovian-mass) planet is in orbit around the system. This will cause
a slow, periodic drift in the times of eclipse minima (Doyle et al.
1995). We show that occasional timing of eclipse minima to within a
couple seconds accuracy (using a standard GPS system) over a few years
is sufficient to allow a survey of eclipsing binary systems with
``Jupiters" around them in over 200 such small-mass systems. Schneider,
J. and L.R. Doyle, (1995), ``Ground-Based Detection of Terrestrial
Planets By Photometry: The Case for CM Draconis," Planetary and Space
Science, in press. Jenkins, J.M., L.R. Doyle, D.K. Cullers, (1995), ``A
Matched Filter Method for Ground-Based Sub-Noise Detection of
Terrestrial Extrasolar Planets in Eclipsing Binaries: Application to CM
Draconis," Icarus, in press. Doyle, L.R., E.T. Dunham, H.-J. Deeg, J.E.
Blue, and J.M. Jenkins, "Detectability of Terrestrial Extrasolar
Planets: U.C. Lick Observations of CM Draconis, J.G.R. Planets, in
press.