Helioseismic inversion techniques have been revealed as powerful tools for inferring the internal structure and dynamics of the Sun. One of the most popular techniques is Regularized Least Squares. When it is used, it is necessary to define an inversion mesh and a penalty function, without an a priori knowledge of the behaviour of the solution. In

The dwarf planet Eris is a trans-Neptunian object with an orbital eccentricity of 0.44, an inclination of 44 degrees and a surface composition very similar to that of Pluto. It resides at present at 95.7 astronomical units (1AU is the Earth-Sun distance) from Earth, near its aphelion and more than three times farther than Pluto. Owing to this great

IN the standard model for type Ia supernovae1, a massive white dwarf in a binary system accretes matter from the companion star until it reaches the Chandrasekhar mass (the stability limit for degenerate-electron stars, corresponding to ~1.4 solar masses), and a runaway thermonuclear explosion ensues. In a popular variant of this model2, the

Jupiter's atmosphere has been sounded in transmission from UV to IR, as if it were a transiting exoplanet by observing one of its satellites, Ganymede, while passing through Jupiter's shadow during a solar eclipse from Ganymede. The spectra show strong extinction due to the presence of aerosols and haze in the atmosphere and strong absorption

We have put into practice the technique to minimize the instrumental polarization (IP) of coude telescopes proposed by Martinez Pillet & Sanchez Almeida (1991): a λ/2-plate inserted into the optical path, with the proper orientation, cancels the IP. The compensation of the Gregory-Coude Telescope at the Observatorio del Teide turns out to fulfil

A prototype system for the Permanent All Sky Survey (PASS) project is presented. PASS is a continuous photometric survey of the entire celestial sphere with a high temporal resolution. Its major objectives are the detection of all giant-planet transits (with periods up to some weeks) across stars up to mag 10.5, and to deliver continuously