Characterization of the hot Neptune GJ 436b with Spitzer and ground-based observations

Understand

We present Spitzer Space Telescope infrared photometry of a secondary eclipse of the hot Neptune GJ436b.

• The observations were obtained using the 8-micron band of the InfraRed Array Camera (IRAC).
• The data spanning the predicted time of secondary eclipse show a clear flux decrement with the expected shape and duration.
• The observed eclipse depth of 0.58 mmag allows us to estimate a blackbody brightness temperature of T_p = 717 +- 35 K at 8 microns.