Heather A. Knutson

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'Hot Jupiter' extrasolar planets are expected to be tidally locked because they are close (<0.05 astronomical units, where 1 au is the average Sun-Earth distance) to their parent stars, resulting in permanent daysides and nightsides. By observing systems where the planet and star periodically eclipse each other, several groups have been able to estimate the(More)
We use multi-band 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(More)
We present new visible and infrared observations of the hot Jupiter Kepler-7b to determine its atmospheric properties. Our analysis allows us to 1) refine Kepler-7b’s relatively large geometric albedo of Ag = 0.35 ± 0.02, 2) place upper limits on Kepler-7b thermal emission that remains undetected in both Spitzer bandpasses and 3) report a westward shift in(More)
The nearby transiting planet HD 189733b was observed during three transits with the Advanced Camera for Surveys of the Hubble Space Telescope in spectroscopic mode. The resulting timeseries of 675 spectra covers the 550–1050 nm range, with a resolution element of ∼8 nm, at extremely high accuracy (signal-to-noise ratio up to 10 000 in 50-nm intervals in(More)
Exoplanetary transmission spectroscopy in the near-infrared using Hubble/NICMOS is currently ambiguous because different observational groups claim different results from the same data, depending on their analysis methodologies. Spatial scanning with Hubble/WFC3 provides an opportunity to resolve this ambiguity. We here report WFC3 spectroscopy of the giant(More)
We present Hubble Space Telescope (HST) optical and near-ultraviolet transmission spectra of the transiting hot Jupiter HD 189733b, taken with the repaired Space Telescope Imaging Spectrograph (STIS) instrument. The resulting spectra cover the range 2900–5700 Å and reach per exposure signal-to-noise ratio levels greater than 11 000 within a 500-Å bandwidth.(More)
We present an optical to near-infrared transmission spectrum of the hot Jupiter HAT-P-1b, based on Hubble Space Telescope observations, covering the spectral regime from 0.29 to 1.027μm with Space Telescope Imaging Spectrograph (STIS), which is coupled with a recent Wide Field Camera 3 (WFC3) transit (1.087 to 1.687μm). We derive refined physical parameters(More)
We present Hubble Space Telescope (HST) optical transmission spectra of the transiting hot Jupiter WASP-12b, taken with the Space Telescope Imaging Spectrograph (STIS) instrument. The resulting spectra cover the range 2900 to 10300 Å which we combined with archival WFC3 spectra and Spitzer photometry to cover the full optical to infrared wavelength regions.(More)
We present Hubble Space Telescope optical and near-IR transmission spectra of the transiting hot-Jupiter WASP-31b. The spectrum covers 0.3–1.7 μm at a resolution R ∼ 70, which we combine with Spitzer photometry to cover the full-optical to IR. The spectrum is dominated by a cloud deck with a flat transmission spectrum which is apparent at(More)
Kepler-13Ab (= KOI-13.01) is a unique transiting hot Jupiter. It is one of very few known short-period planets orbiting a hot A-type star, making it one of the hottest planets currently known. The availability of Kepler data allows us to measure the planet’s occultation (secondary eclipse) and phase curve in the optical, which we combine with occultations(More)