Related papers: A new mechanical stellar wind feedback model for t…
We have used the NASA Infra-Red Telescope Facility (IRTF) to observe the nuclear stellar cluster in the nearby, face-on, giant Scd spiral IC 342. From high resolution (R = 21500) spectra at the 12CO (2-0) bandhead at 2.3 micron we derive a…
We present a detailed analysis of the planetary nebula M4-18 (G146.7+07.6) and its WC10-type Wolf-Rayet central star, based on high quality optical spectroscopy (WHT/UES, INT/IDS, WIYN/DensPak) and imaging (HST/WFPC2). From a non-LTE model…
Globular clusters are considerably more complex structures than previously thought, harbouring at least two stellar generations which present clearly distinct chemical abundances. Scenarios explaining the abundance patterns in globular…
The {\emph{Kepler}} space telescope has provided exquisite data to perform asteroseismic analysis on evolved star ensembles. Studying star clusters offers significant insight into stellar evolution and structure, due to having a large…
We provide a status report on the determination of stellar ages from asteroseismology for stars of various masses and evolutionary stages. The ability to deduce the ages of stars with a relative precision of typically 10 to 20% is a unique…
We present the first radiation-hydrodynamical simulations of the formation of a born-again planetary nebula (PN) triggered by a late thermal pulse (LTP). The 2D radiation-hydrodynamic simulations, performed with the {\sc pluto} code, have…
We have computed with a fine time grid the evolution of the elemental abundances of He, C, N and O ejected by a young (t < 20 Myr) and massive (M$=10^{6}$\,\Msun) coeval stellar cluster with a Salpeter initial mass function (IMF) over a…
Recently, Keerthi Vasan G. et al.(2024 presented spatially resolved observations of a wind outflow in CSWA13, a gravitationally lensed Star-Forming galaxy at z = 1.87. The gravitational lensing allowed for a substantially improved spatial…
We compute photoionization models for the giant extragalactic H II region NGC 5461, and compare their predictions to several observational constraints. Since we aim at reproducing not only the global properties of the region, but its local…
We use Geneva-evolution-code to run evolutionary tracks for stellar masses ranging from $20$ to $85$ $M_\odot$ at SMC metallicity ($Z=0.002$). We upgrade the recipe for stellar winds by adopting our self-consistent m-CAK prescription, which…
We have derived ages for 13 young (<30 Myr) star-forming regions and find they are up to a factor two older than the ages typically adopted in the literature. This result has wide-ranging implications, including that circumstellar discs…
We use several main-sequence models to derive distances (and extinctions), with statistically meaningful uncertainties for 11 star-forming-regions and young clusters. The model dependency is shown to be small, allowing us to adopt the…
We present HST/STIS time-series spectroscopy of the central star of the "Cat's Eye" planetary nebula NGC 6543. Intensive monitoring of the UV lines over a 5.8 hour period reveals well defined details of large-scale structure in the fast…
Using the Wide Field Planetary Camera 2 on board the Hubble Space Telescope, we have imaged a luminous young star cluster in the nearby spiral galaxy NGC 6946. The cluster has an absolute visual magnitude M(V)=-13.2, comparable to the…
The HST archive contains a large collection of images of eta Carinae, and this paper analyzes those most suitable for measuring its expanding Homunculus Nebula. Multiple intensity tracings through the Homunculus reveal the fractional…
We study the Galactic bulge planetary nebula M 2-29 (for which a 3-year eclipse event of the central star has been attributed to a dust disk) using HST imaging and VLT spectroscopy, both long-slit and integral field. The central cavity of M…
Core-collapse supernova remnants are the gaseous nebulae of galactic interstellar media (ISM) formed after the explosive death of massive stars. Their morphology and emission properties depend both on the surrounding circumstellar structure…
Stars form in molecular clouds under the influence of their local environments, yet the role of massive stellar feedback in either triggering or suppressing star formation remains a fundamental question in astrophysics. The Pillars of…
NGC 7129 is a bright reflection nebula located in the molecular cloud complex near l=105.4, b=+9.9, about 1.15 kpc distant. Embedded within the reflection nebula is a young cluster dominated by a compact grouping of four early-type stars:…
Using two epochs of observations with HST/WFPC2 we obtain the stellar proper motions for all stars in the field. The proper motions are used to separate the bulge from the cluster stars. The stellar sequences in the resulting colour-…