J/A+A/508/1011 Planetary transit of TrES-1 and TrES-2 (Rabus+, 2009)
IAC80 time-series photometry of the planetary transit of TrES-1 and TrES-2.
Rabus M., Deeg H.J., Alonso R., Belmonte J.A., Almenara J.M.
<Astron. Astrophys. 508, 1011 (2009)>
=2009A&A...508.1011R 2009A&A...508.1011R
ADC_Keywords: Stars, variable ; Planets ; Photometry
Keywords: planetary systems - methods: N-body simulations -
techniques: photometric
Abstract:
The aim of this work is a detailed analysis of transit light curves
from TrES-1 and TrES-2, obtained over a period of three to four years,
in order to search for variabilities in observed mid-transit times and
to set limits for the presence of additional third bodies. Using the
IAC 80cm telescope, we observed transits of TrES-1 and TrES-2 over
several years. Based on these new data and previously published work,
we studied the observed light curves and searched for variations in
the difference between observed and calculated (based on a fixed
ephemeris) transit times. To model possible transit timing variations,
we used polynomials of different orders, simulated O-C diagrams
corresponding to a perturbing third mass and sinusoidal fits. For each
model we calculated the chi-squared residuals and the False Alarm
Probability (FAP). For TrES-1 we can exclude planetary companions
(>1M{earth}) in the 3:2 and 2:1 MMRs having high FAPs based on our
transit observations from ground. Additionally, the presence of a
light time effect caused by e.g. a 0.09M☉ mass star at a
distance of 7.8AU is possible. As for TrES-2, we found a better
ephemeris of Tc=2453957.63512(28)+2.4706101(18)xEpoch and a good fit
for a sine function with a period of 0.2days, compatible with a moon
around TrES-2 and an amplitude of 57s, but it was not a uniquely low
chi-squared value that would indicate a clear signal. In both cases,
TrES-1 and TrES-2, we were able to put upper limits on the presence of
additional perturbers masses. We also conclude that any sinusoidal
variations that might be indicative of exomoons need to be confirmed
with higher statistical significance by further observations, noting
that TrES-2 is in the field-of-view of the Kepler Space Telescope.
Description:
We observed several transits of TrES-1 and TrES-2 with the IAC 80cm
telescope.
Objects:
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RA (2000) DE Designation(s) (files)
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19 04 09.8 +36 37 58 TrES-1 = NAME TrES-1b (tres1pho)
19 07 14.0 +49 18 59 TrES-2 = NAME TrES-2b (tres2pho)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tres1pho.dat 24 395 IAC80 relative photometry of TrES-1
(phased and binned)
tres2pho.dat 24 207 IAC80 relative photometry of TrES-2
(phased and binned)
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See also:
J/A+A/458/997 : Abundances for 6 transiting planet host stars (Santos+, 2006)
J/AJ/131/2274 : TrES-1 equivalent widths (Sozzetti+, 2006)
J/A+A/475/359 : Extrasolar planets predicting radio fluxes (Griessmeier+ 2007)
J/ApJ/657/1098 : Transit of TrES-1 (Winn+, 2007)
J/A+A/500/L45 : TrES-2 exoplanet transit observations (Mislis+, 2009)
Byte-by-byte Description of file: tres1pho.dat tres2pho.dat
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Bytes Format Units Label Explanations
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1- 9 F9.6 --- Phase Orbital phase
11- 17 F7.4 mag Dmag Differential magnitude
19- 24 F6.4 mag e_Dmag Standard deviation inside bin
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Acknowledgements:
Markus Rabus, mrabus(at)astro.puc.cl
(End) Patricia Vannier [CDS] 22-Oct-2009