Detection of Period Variations in Extrasolar Transiting Planet OGLE-TR-111b
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Citations
The Exoplanet Handbook
The Exoplanet Handbook: Formation and evolution
Transit timing effects due to an exomoon
Transit Timing Effects Due to an Exomoon
References
A simplex method for function minimization
DAOPHOT: A Computer Program for Crowded-Field Stellar Photometry
Cosmological parameters from SDSS and WMAP
Allen's astrophysical quantities
Analytic Lightcurves for Planetary Transit Searches
Related Papers (5)
The use of transit timing to detect terrestrial-mass extrasolar planets.
Frequently Asked Questions (12)
Q2. What are the future works mentioned in the paper "Detection of period variations in extrasolar transiting planet" ?
The authors present some preliminary results here and defer a more detailed study for a future work.
Q3. How many stars were used as template light curves?
The authors obtained photometry of 19 stars distributed as uniformly as possible around OGLE-TR-111to use as template light curves for the TFA.
Q4. How was the signal reconstruction algorithm used?
The signal-reconstruction algorithm was iterated until the relative difference in the curves obtained in two successive steps was less than 10−5.
Q5. How many mmags is the standard deviation before the transit of the second night?
1. The standarddeviation before the transit of the second night is 2.65 mmag, almost reaching the photon noise limit of 2.55 mmag.
Q6. How many days were the O-C times calculated?
(1)The O-C times were computed using the ephemeris for the planetary transits presentedby W07:Tc = 2453799.7516± 0.0002 [HJD] (2) P = 4.0144479± 0.0000041 days .
Q7. What was the fit for the quadratic limb-darkenning model?
The coefficients for the quadratic limb-darkenning model were adjusted from the data instead of fixed to the values of Claret (2000) and, additionally, a linear limb darkenning model was considered, both fixing the linear coefficient to the value computed by Claret (2000) and adjusting it as part of the fit.
Q8. How far from the moon is the moon from the planet?
the hypothesis of an exomoon seems unlikely, since the mass needed to producethe observed O-C times is at least a twentieth of the planetary mass if the moon is at a Hill radius from the planet.
Q9. Why did the authors choose a 5-pixels aperture?
The authors therefore choose a 5-pixels aperture since their goal is to obtain precise measurements of the central times of transits, and therefore the relevance of obtaining the correct amplitude is diminished.
Q10. What are the possible errors in the limbs?
Possible systematic errors may be introduced by the choice of the stellar mass, theorbital period — which affects the determination of the orbital radius—, the model for the limb darkening, and the flux in the reference image.
Q11. What is the fit for the limb-darkening?
The authors considered a quadratic model for the limb-darkening, with coefficients taken from Claret (2000) for a star with Teff = 5000 K, log g = 4.5 cm s −2 and [Fe/H] = 0.2 and microturbulent velocity ξ = 2 km/s.
Q12. How did Deeg and Ribas find the planets?
Deeg et al. (2008) and Ribas et al. (2008) reported indirect detections of unseen companions by monitoring eclipse timing of the binary stellar system CM Draconis (1.5 MJ to 0.1 M candidate) and variations in the orbital parameters of the planetary system around GJ 436 (5 M⊕ companion), respectively.