Dilepton measurements with HADES as probes of hot and dense hadronic matter

Dileptons are an excellent probe to investigate strong-interaction matter under extreme conditions. Their penetrating and virtual nature not only enables invariant measurements, unbiased by the collective expansion of the fireball, but also an insight to the microscopic structure of the dense matter. The High-Acceptance-Di-Electron-Spectrometer (HADES) at GSI, Darmstadt, is uniquely equipped to record and detect these rare probes. Over the last years, it has measured virtual photons, via the di-electron channel, in heavy-ion collisions as well as proton and pion-induced reactions off protons with beam energies of a few GeV per nucleon. Here, we will give a short overview and status update of interesting dilepton observables studied at HADES, including fireball temperature and collectivity studies in terms of anisotropic and radial flow.