  We present model atmospheres for an Earth-like planet orbiting the entire
grid of main sequence FGK stars with effective temperatures ranging from Teff =
4250K to Teff = 7000K in 250K intervals. We model the remotely detectable
spectra of Earth-like planets for clear and cloudy atmospheres at the 1AU
equivalent distance from the VIS to IR (0.4 {\mu}m - 20 {\mu}m) to compare
detectability of features in different wavelength ranges in accordance with
JWST and future design concepts to characterize exo-Earths. We also explore the
effect of the stellar UV levels as well as spectral energy distribution on a
terrestrial atmosphere concentrating on detectable atmospheric features that
indicate habitability on Earth, namely: H2O, O3, CH4, N2O and CH3Cl. The
increase in UV dominates changes of O3, OH, CH4, N2O and CH3Cl whereas the
increase in stellar temperature dominates changes in H2O. The overall effect as
stellar effective temperatures and corresponding UV increase, is a lower
surface temperature of the planet due to a bigger part of the stellar flux
being reflected at short wavelengths, as well as increased photolysis.
Earth-like atmospheric models show more O3 and OH but less stratospheric CH4,
N2O, CH3Cl and tropospheric H2O (but more stratospheric H2O) with increasing
effective temperature of Main Sequence stars. The corresponding spectral
features on the other hand show different detectability depending on the
wavelength observed. We concentrate on directly imaged planets here as
framework to interpret future lightcurves, direct imaging and secondary eclipse
measurements of atmospheres of terrestrial planets in the HZ at varying orbital
positions.
