Atmospheric Characterization of Hot Jupiter CoRoT-1b Based on Secondary Eclipse Spectroscopy

Despite the inability to spatially resolve exoplanets from their host stars, substantial amounts of information can be acquired ranging from chemical composition, thermal structure, and constraints on planet formation. Hot Jupiters present good test cases as they are large, hot, and easily characterizable. In particular, exoplanet CoRoT-1b found in 2007, is especially interesting as it is predicted to be a transitionary planet between hot Jupiters (equilibrium temperatures around 1500K) and ultra hot Jupiters (equilibrium temperature over 2000K). Hot Jupiter atmospheres are expected to have temperatures that decrease with altitude while ultra hot Jupiters may be temperature inverted. In 2012, observations of CoRoT-1b included one primary transit and three secondary eclipses with the Hubble Space Telescope Wide Field Camera 3 (WFC3) combined with the 141 grism (1.1-1.7 μm) in stare mode. This wavelength range is predicted to contain the water absorption feature at 1.4 μm. In 2014, the primary transit of CoRoT-1b was analyzed to probe the structure and composition of the atmosphere but found it to return a featureless spectrum. Despite this, we aimed to further analyze CoRoT-1b through secondary eclipse data producing spectrophotometric light curves corrected for charge trapping also known as the ramp effect in time-series observations with the WFC3. We implemented and improved code for the Time Series Helper & Integration Reduction Tool (tshirt) which extracted spectroscopic data and the Ramp Effect Charge Trapping Eliminator (RECTE). We found that by correcting the ramp effect we are better able to constrain and optimize the transit and secondary eclipse spectra which we compare with representative models in this transitionary temperature regime. It is critical to better understand the effects of systematics to characterize exoplanets as a new generation of observations with the James Webb Space Telescope (JWST), which has stare mode, approach.