Related papers: Two Ring Nebulae around Blue Supergiants in the La…
Evolved low- to intermediate-mass stars are known to shed their gaseous envelope into a large, dusty, molecule-rich circumstellar nebula which typically develops a high degree of structural complexity. Most of the large-scale, spatially…
We present ROSAT observations and analysis of thirteen superbubbles in the Large Magellanic Cloud. Eleven of these observations have not been previously reported. We have studied the X-ray morphology of the superbubbles, and have extracted…
We report the first-ever discovery of a Wolf-Rayet (WR) star in the Large Magellanic Cloud via detection of a circular shell with the Spitzer Space Telescope. Follow-up observations with Gemini-South resolved the central star of the shell…
We have analysed optical, near-, and mid-IR images of the bright planetary nebula (PN) IC 418. These images probe unambiguously for the first time a number of low surface brightness structures and shells around the bright main nebula,…
This paper discusses the location of a sample of planetary nebulae on the HR diagram. We determine the internal velocity fields of 14 planetary nebulae from high-resolution echelle spectroscopy, with the help of photoionization models. The…
Wolf-Rayet stars are amongst the rarest but also most intriguing massive stars. Their extreme stellar winds induce famous multi-wavelength circumstellar gas nebulae of various morphologies, spanning from circles and rings to bipolar shapes.…
A nova super-remnant (NSR) is a greatly-extended structure grown by repeated nova eruptions sweeping the surrounding material away from a nova into a dense outer shell and are predicted to form around all novae. To date, four NSRs are…
Dynamical studies of superbubbles and Wolf-Rayet ring nebulae show discrepancies from the standard, adiabatic model for wind-blown bubbles. We therefore study the physical properties and kinematics of three candidate bubbles blown by single…
Massive stars expel large amounts of mass during their late evolutionary phases. We aim to unveil the physical conditions within the warm molecular environments of B[e] supergiants (B[e]SGs) and yellow hypergiants (YHGs), which are known to…
We observed seven central stars of planetary nebulae (CSPN) in the Large Magellanic Cloud (LMC) with the Far Ultraviolet Spectroscopic Explorer (FUSE), and performed a model-based analysis of these spectra in conjunction with Hubble Space…
We have analyzed high dispersion and high precision spectra of 5 blue horizontal branch stars in the globular cluster M92 to establish that the projected rotational velocity for these stars ranges from 15 to 40 \kms. This is larger than…
We present a spectrophotometric imaging study of the emission bubble N70 (DEM 301) in the Large Magellanic Cloud. N70 is approximately 100 pc in size with a nearly circular shell-like morphology. The nebular emission is powered by an…
Stellar mergers are a brief-lived but common phase in the evolution of binary star systems. Among the many astrophysical implications of these events include the creation of atypical stars (e.g. magnetic stars, blue stragglers, rapid…
We present intermediate-resolution (R$\sim$1000) spectra in the $\sim$3500-10,000 A range of 14 globular clusters in the magellanic irregular galaxy NGC 4449 acquired with the Multi Object Double Spectrograph on the Large Binocular…
We present the results of three-dimensional magnetohydrodynamic (3D MHD) simulations of the plasma flow structure in the vicinity of a compact cluster of young massive stars. The cluster is considered at the evolutionary stage dominated by…
While the extended main-sequence turn-offs (eMSTOs) found in almost all 1--2 Gyr-old star clusters in the Magellanic Clouds are often explained by postulating extended star-formation histories, the tight subgiant branches (SGBs) seen in…
We present the serendipitous discovery of a young stellar cluster in the Galactic disk at l=12deg. Using Keck/NIRSPEC, we obtained high- and low-resolution spectroscopy of several stars in the cluster, and we identified one red supergiant…
Extended main-sequence stars that are dim in the ultraviolet passbands of Hubble Space Telescope (UV-dim stars) are found in several young and intermediate-age Magellanic Cloud star clusters. The obscuring of the dust in the discs of stars…
Surveys of Wolf-Rayet (WR) stars in the Large Magellanic Cloud (LMC) have yielded a fairly complete catalog of 154 known stars. We have conducted a comprehensive, multiwavelength study of the interstellar/circumstellar environments of WR…
CONTEXT: Until now, only one planetary nebula (PN) has been known in the Fornax dwarf spheroidal galaxy. AIMS: The discovery of a second PN candidate, associated with one of the 5 globular clusters in the Fornax dwarf, is reported. METHODS:…