Measuring accurate transit parameters

Winn, Joshua N.

doi:10.1017/s174392130802629x

Cited by 16 publications

(12 citation statements)

References 71 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Besides the well‐known evidence for circularization of planetary orbits, we look for signs of evolution of the stellar rotation towards synchronization. Spin‐orbit alignment is another tidal process accessible to observations in transiting systems, but the present data are not sufficient for statistical analysis (Hébrard et al 2008; Winn 2009). The fourth observable tidal effect – tidal locking of the planet's rotation – is out of reach of observations for extrasolar planets.…”

Section: Introductionmentioning

confidence: 86%

Empirical evidence for tidal evolution in transiting planetary systems

Pont

2009

Monthly Notices of the Royal Astronomical Society

129

102

View full text Add to dashboard Cite

Most transiting planets orbit very close to their parent star, causing strong tidal forces between the two bodies. Tidal interaction can modify the dynamics of the system through orbital alignment, circularisation, synchronisation, and orbital decay by exchange of angular moment. Evidence for tidal circularisation in close-in giant planet is well-known. Here we review the evidence for excess rotation of the parent stars due to the pull of tidal forces towards spin-orbit synchronisation. We find suggestive empirical evidence for such a process in the present sample of transiting planetary systems. The corresponding angular momentum exchange would imply that some planets have spiralled towards their star by substantial amounts since the dissipation of the protoplanetary disc. We suggest that this could quantitatively account for the observed mass-period relation of close-in gas giants. We discuss how this scenario can be further tested and point out some consequences for theoretical studies of tidal interactions and for the detection and confirmation of transiting planets from radial-velocity and photometric surveys.Comment: 10 pages, MNRAS, in Pres

show abstract

Section: Introductionmentioning

confidence: 86%

Empirical evidence for tidal evolution in transiting planetary systems

Pont

2009

Monthly Notices of the Royal Astronomical Society

129

102

View full text Add to dashboard Cite

show abstract

“…from Winn (2009) where δ is the transit depth, T is the total transit duration and τ is the partial, flat transit duration. This leads to an overestimation of the stellar radius, R * from b = a cos i R *…”

Section: Application To Markov Chain Monte Carlo Analysismentioning

confidence: 99%

“…for a circular orbit, modified from Winn (2009), where a is semimajor axis and i is orbital inclination. To avoid this overestimation of stellar radius, the MCMC-fitted stellar radii are generally constrained to reasonably closely follow a Main Sequence relationship to the stellar mass, i.e.…”

Section: Application To Markov Chain Monte Carlo Analysismentioning

confidence: 99%

An improved method for estimating the masses of stars with transiting planets

Enoch¹,

Cameron²,

Parley³

et al. 2010

A&A

133

146

View full text Add to dashboard Cite

Context. To determine the physical parameters of a transiting planet and its host star from photometric and spectroscopic analysis, it is essential to independently measure the stellar mass. This is often achieved by the use of evolutionary tracks and isochrones, but the mass result is only as reliable as the models used. Aims. The recent paper by Torres et al. (2010, A&ARv, 18, 67) showed that accurate values for stellar masses and radii could be obtained from a calibration using T eff , log g and [Fe/H]. We investigate whether a similarly good calibration can be obtained by substituting log ρ -the fundamental parameter measured for the host star of a transiting planet -for log g, and apply this to starexoplanet systems. Methods. We perform a polynomial fit to stellar binary data provided in Torres et al. (2010) to obtain the stellar mass and radius as functions of T eff , log ρ and [Fe/H], with uncertainties on the fit produced from a Monte Carlo analysis. We apply the resulting equations to measurements for seventeen SuperWASP host stars, and also demonstrate the application of the calibration in a Markov Chain Monte Carlo analysis to obtain accurate system parameters where spectroscopic estimates of effective stellar temperature and metallicity are available. Results. We show that the calibration using log ρ produces accurate values for the stellar masses and radii; we obtain masses and radii of the SuperWASP stars in good agreement with isochrone analysis results. We ascertain that the mass calibration is robust against uncertainties resulting from poor photometry, although a good estimate of stellar radius requires good-quality transit light curve to determine the duration of ingress and egress.

show abstract

“…However, following the detection of a transiting exoplanet (Charbonneau et al 2000), several ground-based and space-based survey projects have dramatically increased the number of known systems. Transiting exoplanets allow parameters such as the mass, radius, and density to be precisely determined, as well as their atmospheric properties to be studied during their transits and occultations (Charbonneau et al 2005;Southworth 2009;Winn 2009). …”

Section: Introductionmentioning

confidence: 99%

WASP-78b and WASP-79b: two highly-bloated hot Jupiter-mass exoplanets orbiting F-type stars in Eridanus

Smalley

Anderson

Cameron

et al. 2012

A&A

View full text Add to dashboard Cite

We report the discovery of WASP-78b and WASP-79b, two highly-bloated Jupiter-mass exoplanets orbiting F-type host stars. WASP-78b orbits its V = 12.0 host star (TYC 5889-271-1) every 2.175 days and WASP-79b orbits its V = 10.1 host star (CD-30 1812) every 3.662 days. Planetary parameters have been determined using a simultaneous fit to WASP and TRAPPIST transit photometry and CORALIE radial-velocity measurements. For WASP-78b a planetary mass of 0.89 ± 0.08 M Jup and a radius of 1.70 ± 0.11 R Jup is found. The planetary equilibrium temperature of T P = 2350 ± 80 K for WASP-78b makes it one of the hottest of the currently known exoplanets. WASP-79b its found to have a planetary mass of 0.90 ± 0.08 M Jup , but with a somewhat uncertain radius due to lack of sufficient TRAPPIST photometry. The planetary radius is at least 1.70 ± 0.11 R Jup , but could be as large as 2.09 ± 0.14 R Jup , which would make WASP-79b the largest known exoplanet.

show abstract

Measuring accurate transit parameters

Cited by 16 publications

References 71 publications

Empirical evidence for tidal evolution in transiting planetary systems

Empirical evidence for tidal evolution in transiting planetary systems

An improved method for estimating the masses of stars with transiting planets

WASP-78b and WASP-79b: two highly-bloated hot Jupiter-mass exoplanets orbiting F-type stars in Eridanus

Contact Info

Product

Resources

About