Gemini/GMOS optical transmission spectroscopy of WASP-121b: signs of variability in an ultra-hot Jupiter?

  title={Gemini/GMOS optical transmission spectroscopy of WASP-121b: signs of variability in an ultra-hot Jupiter?},
  author={Jamie Wilson and Neale P. Gibson and Joshua D. Lothringer and David K. Sing and Thomas Mikal-Evans and Ernst J W de Mooij and Nikolay Nikolov and Christopher A. Watson},
  journal={Monthly Notices of the Royal Astronomical Society},
We present ground-based, spectroscopic observations of two transits of the ultra-hot Jupiter WASP-121b covering the wavelength range ≈500–950 nm using Gemini/GMOS. We use a Gaussian process framework to model instrumental systematics in the light curves, and also demonstrate the use of the more generalized Student’s-T process to verify our results. We find that our measured transmission spectrum, whilst showing overall agreement, is slightly discrepant with results obtained using HST/STIS… 

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