Transmission Spectroscopy

Using HST WFC3, STIS, and Spitzer Data to characterise Planetary Atmospheres


Transmission spectroscopy is a powerful tool to probe exoplanetary atmospheres. Here, we study HAT-P-11b, a warm Neptune (~800 K) planet on an eccentric orbit that has a significant water feature in the HST WFC3 bandpass. We re-analyse previously published HST WFC3 data and Spitzer data along with new data from HST STIS using a global consistent framework 'ExoTEP'. The STIS data is useful for characterising the scattering properties of the atmosphere. This work has been accepted for publication in The Astronomical Journal (AJ) and a preprint is available at arXiv:1910.07523.

Atmospheric Forward Models and Retrievals

We wanted to create a publically available retrieval tool that could serve as a first pass test for the numerous observers and scientists out there. Therfore, we used 'ExoTransmit', a widely used tool, to develop a modular Python repository called PLATON. PLATON stands for PLanetary Atmospheric Transmission for Observer Noobs and is designed for easy use and modification. It will serve as a useful first pass retrieval for observers as soon as they have their transmission spectra. This work is led by Michael Zhang and myself under the supervision of Heather Knutson and Eliza Kempton. The first release of the repository is available on Github.