Using Stellar Limb-Darkening to Refine the Properties of HD 209458b

By H. Knutson, D. Charbonneau, R. W. Noyes, T. Brown, R. Gilliland. 2006

240 citations recorded by the source corpus.

We use multiband photometry to refine estimates for the planetary radius and orbital inclination of the transiting planet system HD 209458. We gathered 1066 spectra over four distinct transits with the STIS spectrometer on the Hubble Space Telescope using two gratings with a resolution R = 1500 and a combined wavelength range of 290-1030 nm. We divide the spectra into 10 spectrophotometric bandpasses, five for each grating, of equal wavelength span within each grating, and fit a transit curve over all bandpasses simultaneously. In our fit we use theoretical values for the stellar limb-darkening to further constrain the planetary radius. We find that the radius of HD 209458b is (1.320 ± 0.025)RJup, which is a factor of 2 more precise than current estimates. We also obtain improved estimates for the orbital period P and time of center of transit TC. Although in principle the photon-limited precision of the STIS data should allow us to measure the timing of individual transits to a precision of 2-7 s, we find that uncertainties in the stellar limb-darkening coefficients and residual noise in the data degrade these measurements to a typical precision of ±14 s. Within this level of error, we find no significant variations in the timing of the eight events examined in this work.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/6c44f7cc139bebcd27bc65173401d9848bd54241

How researchers see this paper

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In Astronomy and Astrophysics

1. Jon Fortney
2. N. Madhusudhan
3. A. Showman
4. Sara Seager
5. D. Charbonneau
6. D. Sing
7. D. Deming
8. H. Knutson

In Instrumentation

1. Jon Fortney
2. N. Madhusudhan
3. J. Southworth
4. A. Showman
5. D. Sing
6. D. Charbonneau
7. Sara Seager
8. H. Knutson

Citations in the corpus

• An HST optical-to-near-IR transmission spectrum of the hot Jupiter WASP-19b: detection of atmospheric water and likely absence of TiO (2013, methodology): “Barman (2007) used the STIS data of Knutson et al. (2007) to show evidence of water features in the near-IR consistent with their chemical equilibrium models.”
• Transiting exoplanets from the CoRoT space mission . VI. CoRoT-Exo-3b: the first secure inhabitant of the brown-dwarf desert (2008, methodology): “The limb-darkening parameters issue has been already pointed out by various studies carried out using space-based or ground-based observations (Knutson et al. 2007; Southworth 2008).”
• THE FLAT TRANSMISSION SPECTRUM OF THE SUPER-EARTH GJ1214b FROM WIDE FIELD CAMERA 3 ON THE HUBBLE SPACE TELESCOPE (2011, background): “These ramps are reminiscent of those seen in highcadence Spitzer light curves at 8 and 16 µm (e.g. Deming et al. 2006; Knutson et al. 2007a; Charbonneau et al. 2008) which Agol et al. (2010) recently proposed may be due to “charge trapping” within the detector pixels.”
• TRANSMISSION SPECTRA OF THREE-DIMENSIONAL HOT JUPITER MODEL ATMOSPHERES (2009, methodology): “The Knutson et al. (2007b) data set was further analyzed by Barman (2007) and D. Sing and collaborators (Sing et al. 2008a,b; Lecavelier des Etangs et al. 2008b; Désert et al. 2008).”
• Transits and Occultations (2010, methodology): “Among the most spectacular data yet obtained in this field was the 33 hr observation by Knutson et al. (2007b) of the K star HD 189733, spanning both a transit and occultation of its giant planet.”
• A DETECTION OF WATER IN THE TRANSMISSION SPECTRUM OF THE HOT JUPITER WASP-12b AND IMPLICATIONS FOR ITS ATMOSPHERIC COMPOSITION (2015, result): “Similar disagreement with model limb darkening has been seen for other high quality data (e.g. Knutson et al. 2007).”
• Improving Stellar and Planetary Parameters of Transiting Planet Systems: The Case of TrES-2 (2007, background): “…planets (Charbonneau et al. 2006, 2007b; Bakos et al. 2006; Gillon et al. 2006; Holman et al. 2006, 2007a, 2007b; Winn et al. 2007a, 2007b, 2007c; Knutson et al. 2007; Pont et al. 2007; Minniti et al. 2007; Diaz et al. 2007), the measured a/R? values are likely to be much better now than in the…”
• Hubble Space Telescope transmission spectroscopy of the exoplanet HD 189733b: high‐altitude atmospheric haze in the optical and near‐ultraviolet with STIS (2011, background): “Finally, orbital phase curves can probe the global temperature distribution and study atmospheric circulation (Knutson et al. 2007a).”
• Long-term tidal evolution of short-period planets with companions (2007, background): “These are HD 209458b (Charbonneau et al. 2000; Henry et al. 2000; Knutson et al. 2007), WASP-1b (Collier Cameron et al. 2006) and HAT-P-1b (Bakos et al. 2006), for which the planetary radii and other observationally derived parameters are listed in Table 1.”
• Hubble Space Telescope hot Jupiter transmission spectral survey: a detection of Na and strong optical absorption in HAT-P-1b (2013, background): “Similar to Knutson et al. (2007) we found that the fringe effect do not influence significantly the transmission spectrum when using large bin sizes (such as our three reddest bins).”
• Hubble Space Telescope STIS Optical Transit Transmission Spectra of the Hot Jupiter HD 209458b (2008, methodology): “The relative planetary radii, when comparing between different wavelengths, are largely independent of the uncertainties of the stellar parameters and can be determined much more precisely than the actual radii values themselves (Knutson et al. 2007).”
• Exoplanet Atmospheres: Physical Processes (2010, methodology): “These properties led to the concept (Knutson et al. 2007a) that the ramp is due to charge trapping in the detector.”
• Tidal Evolution of Close-in Extrasolar Planets (2007, background): “…Bakos et al. 2007a; Bakos et al. 2007b; Butler et al. 2006; Da Silva et al. 2006; Deming et al. 2007; Gillon et al. 2007; Johnson et al. 2006; Knutson et al. 2007; Laughlin et al. 2005; Lovis et al. 2006; McArthur et al. 2004; Maness 2007; Mayor 2004; Moutou et al. 2006; Rivera et al. 2005;…”
• Homogeneous studies of transiting extrasolar planets – I. Light-curve analyses (2008, methodology): “The method has been used before on several TEPs (e.g. Bouchy et al. 2005a; Pont et al. 2005; Gillon et al. 2007a; Knutson et al. 2007a).”