Related papers: On determining the chemical composition of planeta…

This review provides useful background and information on how we find, vet and compile Planetary Nebulae (PNe) candidates and verify them. It presents a summary of the known Galactic PNe population and their curation in the Hong…

We study the oxygen abundance in five H II regions and seven planetary nebulae (PNe) located within 2 kpc from the Sun that have available spectra of high quality. Our analysis uses a similar procedure and the same atomic data to derive…

Premise: This report is intended to provide useful background and information on how we find detect and compile Planetary Nebulae PNe candidates and then verify them. It is for postgraduate students entering the field and for more general…

We present a spectroscopic investigation of 25 objects previously reported as possible Planetary Nebulae (PNe) in recent catalogs to obtain their physical properties and to establish their true nature. We found 11 objects showing intense…

The compositions of stars are a critical diagnostic tool for many topics in astronomy such as the evolution of our Galaxy, the formation of planets, and the uniqueness of the Sun. Previous spectroscopic measurements indicate a large…

Planetary nebulae (and in general any photoionized region) can be classified as ionization-bounded or density-bounded. It is important to determine in which case is the planetary nebula studied to be able to estimate from nebular…

Planetary nebulae have been used as tracers of light and kinematics for the stellar populations in early-type galaxies since more than twenty years. Several empirical properties have surfaced: for example the invariant bright cut-off of the…

We have undertaken a large spectroscopic survey of over 80 planetary nebulae with the goal of providing a homogeneous spectroscopic database between 3600-9600 Angstroms, as well as a set of consistently determined abundances, especially for…

We present new interstellar dust models which have been derived by simultaneously fitting the far-ultraviolet to near-infrared extinction, the diffuse infrared (IR) emission and, unlike previous models, the elemental abundance constraints…

Stellar abundances for a large number of stars are key information for the study of Galactic formation history. Large spectroscopic surveys such as DESI and LAMOST take median-to-low resolution ($R\lesssim5000$) spectra in the full optical…

Spectral retrieval has long been a powerful tool for interpreting planetary remote sensing observations. Flexible, parameterised, agnostic models are coupled with inversion algorithms in order to infer atmospheric properties directly from…

Elemental abundances provide a powerful diagnostic of the physical mechanisms and processes that heat the solar atmosphere and drive the solar wind. The First Ionisation Potential (FIP) effect and its inverse (IFIP) are observed both on the…

This paper is the first of a series specifically studying the abundances of sulfur, chlorine, and argon in Type II planetary nebulae (PNe) in the Galactic disk. Ratios of S/O, Cl/O, and Ar/O constitute important tests of differential…

We present the results of a near-infrared narrowband imaging survey of planetary nebulae. Objects were selected in a way that complements similar surveys done at visible and near-infrared wavelengths. No new detections of molecular hydrogen…

We derive the stellar and circumstellar parameters of the Galactic compact planetary nebula Hen 2-90 with two models: the classical constant density nebula model where the emission (especially of the forbiden lines) is formed in a sphere or…

We perform a homogeneous analysis of the Fe/Ni abundance ratio in eight Galactic planetary nebulae (PNe) and three Galactic H II regions that include the Orion nebula, where we study four nebular zones and one shocked region. We use [Fe…

The interpretation of observations over different wavelength domains, which now exist over a large fraction of the sky, will be used to determine relationships between a nebula and its' illuminating source. The illuminating source of a high…

Powerful new, high resolution, high sensitivity, multi-frequency, wide-field radio surveys such as the Australian Square Kilometre Array Pathfinder (ASKAP) Evolutionary Map of the Universe (EMU) are emerging. They will offer fresh…

The determination of the heavy element abundances from giant extragalactic H II regions is based on collisionally excited lines. We argue that in the presence of temperature variations the abundances determined are lower limits to the real…

We examine contributions of second order physical processes to results of stellar evolution calculations amenable to direct observational testing. In the first paper in the series (Young et al. 2001) we established baseline results using…