"Measurements of the $W^+\rightarrow\mu^+\nu$ and $W^-\rightarrow\mu^-\bar{\nu}$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton-proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2 $\textrm{fb}^{-1}$. The integrated cross-sections for $W^+\rightarrow\mu^+\nu$ and $W^-\rightarrow\mu^-\bar{\nu}$ production are measured in a fiducial phase space defined at the particle level by requiring the muon transverse momentum to be greater than 25 GeV and the neutrino transverse momentum to be greater than 25 GeV. The absolute muon pseudorapidity is required to be less than 2.4. The W boson transverse mass must be at least 40 GeV. The differential cross-sections and charge asymmetry are measured in the same fiducial phase space as for the integrated measurement. These are measured in 11 bins of absolute muon pseudorapidity between 0 and 2.4 with bin edges at 0, 0.21, 0.42, 0.63, 0.84, 1.05, 1.37, 1.52, 1.74, 1.95, 2.18, and 2.4. See 1904.05631 for more details."