Aims: Near-IR photometry of dwarf irregular galaxies (dIs) has been acquired to expand the sample of objects suitable for investigating the fundamental plane (FP) discovered previously by us. Data for blue compact dwarfs (BCDs), dwarf ellipticals (dEs), and dwarf spheroidal galaxies (dSphs) are amalgamated to evaluate how closely these classes of

We present the current status of the Canarias InfraRed Camera Experiment (CIRCE) an all-reflective near-IR, imager, spectrograph, and polarimeter for the 10.4-meter Gran Telescopio Canarias (GTC). In particular, we review the progress of the opto- and cryo- mechanical design and manufacture, focusing on the custom filter, lyot, and grism wheels

Aims: Using data from five clusters of galaxies within the redshift range 0.15 ≤ z ≤ 0.25, imaged with the Nordic Optical Telescope (NOT) in the central ≈1 Mpc2 in very good seeing conditions, we have performed an exhaustive inspection of their bright galaxy population. That range of redshift, where only a small amount of data with the required

The blue supergiant Sher25 is surrounded by an asymmetric, hourglass-shaped circumstellar nebula. Its structure and dynamics have been studied previously through high-resolution imaging and spectroscopy, and it appears dynamically similar to the ring structure around SN1987A. Here, we present long-slit spectroscopy of the circumstellar nebula

Laser Guide Stars -LGS- has been widely proposed to extend the domain of stable operation for adaptive optics systems in large telescopes. As LGS are formed in a finite distance, bistatic schemes with two or more additional telescopes has been noted as the most efficient configuration from the point of view of full aperture tip-tilt correction. In

We have been testing at laboratory commercial variable attenuators commonly used in telecommunication applications for their used in astronomy. Such variable attenuators are going to be included in the central fibers of the integral field unit (IFU) of the prototype instrument EDiFiSE (Equalized and Diffraction-limited Field Spectrograph Experiment