The importance of the study of Planetary Nebulae (PNe) in our Galaxy and in external galaxies is outlined, with the aim of highlighting how the combined study of galactic and extragalactic PNe can bring a substantial contribution to our understanding of the late stages of stellar evolution and of related astrophysical topics. We then illustrate the

We describe the progress of a large optical and near-infrared imaging study of a complete sample of 57 spiral galaxies. We have obtained B, I, K' and Hα imaging to map stellar populations and massive star formation (SF) across the arm and interarm regions, in order to study the distribution of mass and SF in these different and distinct

The survey for DUST in Nearby Galaxies with Spitzer (DUSTiNGS) identified several candidate Asymptotic Giant Branch (AGB) stars in nearby dwarf galaxies and showed that dust can form even in very metal-poor systems ({\boldsymbol{Z}}∼ 0.008 {Z}ȯ ). Here, we present a follow-up survey with WFC3/IR on the Hubble Space Telescope (HST), using filters

We present the first results of a combined HST/IUE/ground-based spectroscopic monitoring campaign on the Seyfert 1 galaxy NGC 5548 that was undertaken in order to address questions that require both higher temporal resolution and higher signal-to-noise ratios than were obtained in our previous multiwavelength monitoring of this galaxy in 1988 -- 89

Observational results concerning possible changes in the granulation of Main Sequence stars were found by analysing their seismic power spectra obtained from photometric microvariability. We analysed as many as 178 stars with spectral types F, G, K, and M observed for 54 days. We present evidence of changes in the lifetime and contrast of the

We have derived a new H_{β} absorption index definition, which is fully optimized as an age indicator for old and intermediate-aged stellar populations. Rather than using stellar spectra, we employed theoretical SEDs at moderately high resolution for simple stellar populations of different ages and metallicities. The new index, which is virtually