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The Use of High-resolution Infrared Thermography HRIT for the Study of Ice Nucleation and Ice Propagation in Plants
Published on: May 8, 2015
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Infrared radiation from an extrasolar planet.
Drake Deming1, Sara Seager, L Jeremy Richardson
1Planetary Systems Laboratory and Goddard Center for Astrobiology, Code 693, NASA's Goddard Space Flight Center, Greenbelt, Maryland 20771, USA. Leo.D.Deming@nasa.gov
Nature
|March 24, 2005
Summary
Astronomers detected infrared radiation from the hot Jupiter HD 209458b, confirming it is heated by its star. This finding suggests the planet likely has a circular orbit, challenging previous theories about its large size.
Area of Science:
- Astronomy and Astrophysics
- Exoplanetary Science
Background:
- Hot Jupiters are gas giant exoplanets orbiting very close to their stars.
- These planets are expected to be hot and emit infrared radiation.
- HD 209458b is an exoplanet with an unusually large radius, possibly due to tidal dissipation requiring orbital eccentricity.
Purpose of the Study:
- To detect and characterize infrared radiation from the exoplanet HD 209458b.
- To investigate the thermal emission of HD 209458b and its implications for orbital dynamics.
Main Methods:
- Observing the decrement in infrared flux (24 micrometers) during the secondary eclipse of HD 209458b.
- Analyzing the timing of the secondary eclipse relative to planetary transits.
Main Results:
- Direct detection of 24-micrometer infrared radiation from HD 209458b (55 +/- 10 microJy).
- Measured brightness temperature of 1,130 +/- 150 K, consistent with stellar irradiation.
- Secondary eclipse timing indicates a near-circular orbit, contradicting theories requiring significant orbital eccentricity.
Conclusions:
- The detected infrared emission confirms significant stellar heating of HD 209458b.
- The precise timing of the secondary eclipse suggests HD 209458b has a dynamically insignificant orbital eccentricity.
- This challenges explanations for the planet's large radius that rely on tidal dissipation driven by orbital eccentricity.
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