Aims: We search for very small-diameter galactic planetary nebulae (PNe) representing the earliest phases of PN evolution. The IPHAS catalogue of Hα-emitting stars provides a useful basis for this study since all sources present in this catalogue must be of small angular diameter. Methods: The PN candidates are selected based on their location in

Aims: Our goal is to study the physical properties of the circumstellar environment of young stellar objetcs (YSOs). In particular, the determination of the scattering mechanism can help us to constrain the optical depth of the disk and/or envelope in the near infrared. Methods: We used the IAGPOL imaging polarimeter along with the CamIV infrared

The recent discovery of multiple stellar populations in massive Galactic globular clusters poses a serious challenge for models of star cluster formation and evolution. An unique angle on this problem is being provided by intermediate-age clusters in the Magellanic Clouds with peculiar main-sequence turn-off morphologies. These clusters are young

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Toda teoría que pretenda explicar la formación de las galaxias y su evolución posterior debe dar cuenta de la influencia del entorno sobre sus propiedades observacionales. Los cúmulos de galaxias, dadas las peculiares características que presentan --una alta densidad de materia bariónica en forma de galaxias y un medio intracumular caliente