AWhat changed
Knutson and colleagues used the Spitzer Space Telescope to measure an 8-micrometre phase curve of the transiting hot Jupiter HD 189733b over slightly more than half an orbit. They inferred a modest day–night brightness contrast and an eastward offset of the brightest hemisphere, consistent with atmospheric transport of heat. A regularized longitudinal-slice fit gave a coarse brightness map rather than a spatially resolved picture.
Scientific scope
Knutson and colleagues used the Spitzer Space Telescope to measure an 8-micrometre phase curve of the transiting hot Jupiter HD 189733b over slightly more than half an orbit. They inferred a modest day–night brightness contrast and an eastward offset of the brightest hemisphere, consistent with atmospheric transport of heat. A regularized longitudinal-slice fit gave a coarse brightness map rather than a spatially resolved picture. The measured signal is combined star-plus-planet flux and depends on correction of an illumination-dependent detector ramp and potential stellar-spot variability. The reported 973 ± 33 K and 1212 ± 11 K are minimum and maximum hemisphere-averaged brightness temperatures at one wavelength, not full three-dimensional atmospheric temperatures. The phase-curve maximum is about 16° before opposition; the separately fitted brightest longitude slice is around 30° east of the substellar point. Latitude structure is assumed, not measured, and the map has coarse 30° longitudinal bins. Winds, heat redistribution and orbital eccentricity are interpretations subject to model and timing assumptions.
Evidence
The linked original works support the scoped statement and contribution attribution. WRS has not independently replayed experiments or reconstructed a full mathematical proof. The measured signal is combined star-plus-planet flux and depends on correction of an illumination-dependent detector ramp and potential stellar-spot variability. The reported 973 ± 33 K and 1212 ± 11 K are minimum and maximum hemisphere-averaged brightness temperatures at one wavelength, not full three-dimensional atmospheric temperatures. The phase-curve maximum is about 16° before opposition; the separately fitted brightest longitude slice is around 30° east of the substellar point. Latitude structure is assumed, not measured, and the map has coarse 30° longitudinal bins. Winds, heat redistribution and orbital eccentricity are interpretations subject to model and timing assumptions.
Contributors
- The named authors in the research record · SCIENCE: These are the listed authors of the cited contribution sources. Paper authorship does not quantify individual effort. An incomplete list is explicitly marked; same names are not automatically merged.
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