The Instituto de Astrofisica de Canarias (IAC) is undertaking the design and construction of a common-user near IR spectrograph (LIRIS) for the Cassegrain focus of the 4.2 m William Herschel Telescope sited at the Observatorio del Roque de Los Muchachos. LIRIS will be a near IR intermediate-resolution spectrograph designed to operate over a

Selecting stars with previously measured or estimated rotational periods we have measured equivalent widths of the Li doublet (6708 A) in 8 stars of the Hyades late main sequence and, combining our data with literature values, derive a homogeneous set of Li abundances. The graph of Li against period is monotonic, taking, not surprisingly, a similar

The way in which the evaluation of any moment of the mass distribution, as given by the Zeldovich (1970) approximation, may be reduced to the computation of an integral is shown. A method for obtaining a two-point correlation function from the product of the density fluctuation and the Lagrangian coordinate is presented. Local approximations that

A study has been undertaken of the physical conditions of the ionized gas within the starburst region of the galaxy NGC 253, using long slit spectroscopy at high spatial and spectral resolution. The aim was to identify the appropriate parameters describing the dynamics of the gas and the excitation conditions, in relation with the starburst process

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We present a long-term programme for timing the eclipses of white dwarfs in close binaries to measure apparent and/or real variations in their orbital periods. Our programme includes 67 close binaries, both detached and semi-detached and with M-dwarfs, K-dwarfs, brown dwarfs or white dwarfs secondaries. In total, we have observed more than 650