of Sheffield, Sheffield, S3 7RH, UK\
    $^3$Astrophysics Research Institute, Liverpool John Moores University, Liverpool, L3 5RF, UK\
    $^4$ARC, School of Mathematics and Physics, Queen’s University Belfast, University Road, Belfast BT7 1NN, UK\
    $^5$Instituto de Astrofísica de Canarias, Vía Láctea s/n, 38205, La Laguna, Spain
bibliography:
- 'Report\_ref.bib'
title: 'Transmission spectroscopy of the inflated exoplanet WASP-52b, and evidence for a bright region on the stellar surface'
---

stars: planetary systems – stars: individual: WASP-52 – stars: starspots

Introduction
============

Transmission spectroscopy using HST/STIS was used to detect the first spectral feature of any exoplanet, that of the narrow core of atomic sodium originating from the upper atmosphere of HD209458b [@Charbonneau2002]. Broad-band opacity sources were later detected in this planet’s atmosphere in the form of the pressure broadened wings of NaI [@Sing2008_spectra] and a blueward slope in the transmission spectrum interpreted as Rayleigh scattering by H$_2$ [@Etangs2008_HD209]. This feature was also seen in HST data for HD189733b (@Pont2008; @Sing2011), however the absence of the broad wings of NaI suggested the presence of silicate condensates in the upper atmosphere of the planet [@Etangs2008_HD189]. Recent studies of hot Jupiters with HST have revealed a diverse array of atmospheres from clear to cloudy (e.g. @Sing2016). 