• DOI:10.1093/mnras/stx984
• Corpus ID: 118826582

A precise optical transmission spectrum of the inflated exoplanet WASP-52b

@article{Louden2017APO,
  title={A precise optical transmission spectrum of the inflated exoplanet WASP-52b},
  author={Tom Louden and Peter J. Wheatley and Patrick G. J. Irwin and James Kirk and Ian Skillen},
  journal={Monthly Notices of the Royal Astronomical Society},
  year={2017},
  volume={470},
  pages={742-754}
}

• T. Louden, P. Wheatley, +2 authors I. Skillen
• Published 27 March 2017
• Physics, Geology
• Monthly Notices of the Royal Astronomical Society

We have measured a precise optical transmission spectrum for WASP-52b, a highly inflated hot Jupiter with an equilibrium temperature of 1300 K. Two transits of the planet were observed spectroscopically at low resolution with the auxiliary-port camera (ACAM) on the William Herschel Telescope (WHT), covering a wide range of 4000-8750 \AA. We use a Gaussian process approach to model the correlated noise in the multi-wavelength light curves, resulting in a high precision relative transmission spectrum with errors on the order of a pressure scale height. We attempted to fit a variety of different representative model atmospheres to the transmission spectrum, but did not find a satisfactory match to the entire spectral range. For the majority of the covered wavelength range (4000-7750 \AA) the spectrum is flat, and can be explained by an optically thick and grey cloud layer at 0.1 mbar, but this is inconsistent with a slightly deeper transit at wavelengths $> 7750$ \AA. We were not able to find an obvious systematic source for this feature, so this opacity may be the result of an additional unknown absorber.