Nebular emission lines are a powerful diagnostic tool for tracing the chemical evolution in star-forming galaxies (SFGs) across cosmic time. Due to their proximity, SGFs are ideal for studying the physical properties, stellar population, and nebular gas in much more detail. The COS Legacy Spectroscopy SurveY (CLASSY) is a treasury survey that

Using CGMS deep integral field data we have discovered that the massive galaxy NGC 1277 has no dark matter. This is the first time that a galaxy as massive as the Milky Way or more is found to be dark matter deficient. This result is unexpected within the Lambda-CDM cosmological paradigm. We propose several alternatives to explain this intriguing

In this seminar I will focus on how the avalanche of new data changes our views on how our Galaxy formed and evolved. Precise astrometric, spectroscopic, photometric and asteroseismic data can be combined to pin down different processes that have shaped the Milky Way. This data will be discussed and illustrated with examples of what is possible to