Context : Solar-analog stars provide an excellent opportunity to study the Sun ’ s evolution , i.e .
the changes with time in stellar structure , activity , or rotation for solar-like stars .
The unparalleled photometric data from the NASA space telescope Kepler allows us to study and characterise solar-like stars through asteroseismology .

Aims : We aim to spectroscopically investigate the fundamental parameter and chromospheric activity of solar analogues and twins , based on observations obtained with the Hermes spectrograph and combine them with asteroseismology .
Therefore , we need to build a solar atlas for the spectrograph , to provide accurate calibrations of the spectroscopically determined abundances of solar and late type stars observed with this instrument and thus perform differential spectral comparisons .

Methods : We acquire high-resolution and high signal-to-noise ( S/N ) spectroscopy to construct three solar reference spectra by observing the reflected light of Vesta and Victoria asteroids and the jovian moon Europa ( 100 \lesssim S/N \lesssim 450 ) with the Hermes spectrograph .
We then observe the Kepler solar analog KIC 3241581 ( S/N \sim 170 ) .
For this star , the fundamental spectral parameters are extracted in a differential analysis .
Sufficient S/N in the near ultraviolet allows us to investigate the chromospheric magnetic activity in both objects .

Results : We constructed three solar spectrum atlases from 385 to 900 nm obtained with the Hermes spectrograph from observations of two bright asteroids and a jovian moon .
A comparison between our solar spectra atlas to the Kurucz and HARPS solar spectrum shows an excellent agreement .
KIC 3241581 was found to be a long-periodic binary system .
The fundamental parameter for the stellar primary component are T _ { eff } = 5689 \pm 11K , \log g = 4.385 \pm 0.005 , [ Fe/H ] = +0.22 \pm 0.01 , being in agreement with the published global seismic values confirming its status of solar analogue .
The chromospheric activity level is compatible to the solar magnetic activity observed during 2014 and 2015 .

Conclusions : Our solar atlas is an essential tool for the analysis of solar-like stars and to characterise solar analogs and twins with Hermes .
The differential analysis , using the presented solar atlas from Hermes observations allows us to obtain the fundamental parameters with a very high accuracy .
KIC 3241581 is a metal rich solar analogue with a solar-like activity level in a binary system of unknown period .