  Small planets around low-mass stars often show orbital periods in a range
that corresponds to the temperate zones of their host stars which are therefore
of prime interest for planet searches. Surface phenomena such as spots and
faculae create periodic signals in radial velocities and in observational
activity tracers in the same range, so they can mimic or hide true planetary
signals. We aim to detect Doppler signals corresponding to planetary
companions, determine their most probable orbital configurations, and
understand the stellar activity and its impact on different datasets. We
analyze 22 years of data of the M1.5V-type star Gl49 (BD+61 195) including
HARPS-N and CARMENES spectrographs, complemented by APT2 and SNO photometry.
Activity indices are calculated from the observed spectra, and all datasets are
analyzed with periodograms and noise models. We investigate how the variation
of stellar activity imprints on our datasets. We further test the origin of the
signals and investigate phase shifts between the different sets. To search for
the best-fit model we maximize the likelihood function in a Markov Chain Monte
Carlo approach. As a result of this study, we are able to detect the
super-Earth Gl49b with a minimum mass of 5.6 Ms. It orbits its host star with a
period of 13.85d at a semi-major axis of 0.090 au and we calculate an
equilibrium temperature of 350 K and a transit probability of 2.0%. The
contribution from the spot-dominated host star to the different datasets is
complex, and includes signals from the stellar rotation at 18.86d, evolutionary
time-scales of activity phenomena at 40-80d, and a long-term variation of at
least four years.
