H II regions, ionized nebulae associated to massive star formation, exhibit a wealth of emission lines that are the fundamental basis for estimating the chemical composition of the Universe. For more than 80 years, a discrepancy of a factor of around two between heavy-element abundances derived with collisional excited lines (CELs) and the weaker

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

More than 200 species have been detected in the interstellar medium (ISM), among them many molecules, radicals and ions, containing the −C≡N functional group . Both linear and branched isomers of propyl cyanide (PrCN; C 3 H 7 CN) are ubiquitous in interstellar space. To date, PrCN is one of the most complex molecules found in the interstellar