  Till date, only a handful exo-atmospheres have been well characterized,
mostly by means of the transit method. Data show exoplanet atmospheres to be
diverse. However, this is based on a small number of cases. Here we focus our
study on the exo-atmosphere of Qatar-1b, an exoplanet that looks much like HD
189733b regarding its host star activity level, their surface gravity, scale
height, equilibrium temperature and transit parameters. Thus, our motivation
relied on carrying out a comparative study of their atmospheres, and assess if
these are regulated by their environment. In this work we present one primary
transit of Qatar-1b obtained during September, 2014, using the 8.1 m GEMINI
North telescope. The observations were performed using the GMOS-N instrument in
multi-object spectroscopic mode. We collected fluxes of Qatar-1 and six more
reference stars, covering the wavelength range between 460 and 746 nm. The
achieved photometric precision of 0.18 parts-per-thousand in the white light
curve, at a cadence of 165 seconds, makes this one of the most precise datasets
obtained from the ground. We created 12 chromatic transit light curves that we
computed by integrating fluxes in wavelength bins of different sizes, ranging
between 3.5 and 20 nm. Although the data are of excellent quality, the
wavelength coverage and the precision of the transmission spectrum are not
sufficient to neither rule out or to favor classic atmospheric models.
Nonetheless, simple statistical analysis favors the clear atmosphere scenario.
A larger wavelength coverage or space-based data is required to characterize
the constituents of Qatar-1b's atmosphere and to compare it to the well known
HD 189733b. On top of the similarities of the orbital and physical parameters
of both exoplanets, from a long Halpha photometric follow-up of Qatar-1,
presented in this work, we find Qatar-1 to be as active as HD 189733.
