  We explore the general astrobiological significance of F-type main-sequence
stars with masses between 1.2 and 1.5 Msun. Special consideration is given to
stellar evolutionary aspects due to nuclear main-sequence evolution. DNA is
taken as a proxy for carbon-based macromolecules following the paradigm that
extraterrestrial biology may be most likely based on hydrocarbons.
Consequently, the DNA action spectrum is utilized to represent the impact of
the stellar UV radiation. Planetary atmospheric attenuation is taken into
account based on parameterized attenuation functions. We found that the damage
inflicted on DNA for planets at Earth-equivalent positions is between a factor
of 2.5 and 7.1 higher than for solar-like stars, and there are intricate
relations for the time-dependence of damage during stellar main-sequence
evolution. If attenuation is considered, smaller factors of damage are obtained
in alignment to the attenuation parameters. This work is motivated by earlier
studies indicating that the UV environment of solar-type stars is one of the
most decisive factors in determining the suitability of exosolar planets and
exomoons for biological evolution and sustainability.
