We present an overview of the initial results from the Chandra Planetary Nebula Survey (CHANPLANS), the first systematic (volume-limited) Chandra X-Ray Observatory survey of planetary nebulae (PNe) in the solar neighborhood. The first phase of CHANPLANS targeted 21 mostly high-excitation PNe within ~1.5 kpc of Earth, yielding four detections of

We present deep spectra of ring nebulae associated with Wolf-Rayet (WR) and O-type stars: NGC 6888, G2.4+1.4, RCW 58, S 308, NGC 7635 and RCW 52. The data have been taken with the 10m Gran Telescopio Canarias and the 6.5m Clay Telescope. We extract spectra of several apertures in some of the objects. We derive C2+ and O2+ abundances from faint

Context. Early B-type stars are invaluable indicators of elemental abundances of their birth environments. In contrast to the surrounding neutral interstellar matter (ISM) and H ii regions, their chemical composition is unaffected by depletion onto dust grains and the derivation of different abundances from recombination and collisional lines. In

We present stellar population models for starbursts in a sample of eleven Wolf-Rayet galaxies. Taking into account the observational data available, we try to reconstruct the number of Wolf-Rayet stars observed and estimate the number of type II supernovae that have exploded in the ionizing cluster. Using the stellar yields of the most recent

Observational and theoretical evidence suggest that long gamma-ray bursts (GRBs) originate from the collapse of massive stars, while short bursts are caused by the coalescence of stellar compact objects. Finding direct evidence for both scenarios is challenging. Intriguingly, the afterglow evolution depends on the density profile of the circumburst

This article presents narrow-band Hα and [OIII] images of the interacting pair of galaxies NGC 5953 (with a Seyfert type 2 nucleus) and NGC 5954 (with a LINER). Long-slit spectroscopy, from [NeV] lambda3425A to [SIII] lambda9532A, at intermediate resolution along position angles 44 deg and 182 deg through the nucleus of NGC 5953, is also presented