The extension of the highly successful Doppler technique into the near-infrared (0.9-2.5 μm) is opening new parameter domains for extra-solar planet searches in terms of ages and masses of the primary stars. Here we present the current status of NAHUAL, a next generation near-infrared spectrograph for the 10.4-meter Gran Telescopio Canarias (GTC)

We present new photometric and spectroscopic observations of an unusual luminous blue variable (LBV) in NGC 3432, covering three major outbursts in 2008 October, 2009 April and 2009 November. Previously, this star experienced an outburst also in 2000 (known as SN 2000ch). During outbursts the star reached an absolute magnitude between -12.1 and -12

We analyze the propagation of waves in sunspots from the photosphere to the chromosphere using time series of co-spatial Ca II H intensity spectra (including its line blends) and polarimetric spectra of Si I λ10,827 and the He I λ10,830 multiplet. From the Doppler shifts of these lines we retrieve the variation of the velocity along the line of

A lunar eclipse offers a unique opportunity to investigate the terrestrial atmosphere. A recent work (Pallé et al. 2009) has published the Earth’s transmission spectrum from 0.36 to 2.40 μm obtained during the partial lunar eclipse of August 16th 2008. We have set out to interpret the measured spectrum, and assess to what extent the conclusions can

Approximately half the baryons in the local Universe are thought to reside in the warm-hot intergalactic medium (WHIM), i.e. diffuse gas with temperatures in the range 105 T 107K. Emission lines from metals in the UV band are excellent tracers of the cooler fraction of this gas, with T ~103photons-1cm-2sr-1) comes from relatively dense (ρ >

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