A-type asteroids are usually found in the main asteroid belt and their spectra are very similar to spectra of the silicate mineral olivine (Cruikshank and Hartmann 1984). The existence of olivine-rich asteroids is a result of differentiation, those being the pieces of the mantle of a larger parent body. Extraterrestrial sources of such material

The direct access to the interior of the Sun has been possible, over the past 25 years, by successfully applying seismic techniques to detect and to characterize the whole spectrum of its oscillation eigenmodes. The unique and huge amount of observational data provided by earth-based networks and space-borne instruments, has allowed a high degree

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We discuss the use of the spectral range near 7570 Å to determine the Mg isotopic ratios in carbon stars using the B'2 Sigma +-X 2 Sigma + system of the MgH molecule. We also compare with the spectral range near 5140 Å that has been commonly used in normal stars (oxygen-rich stars). The region near 5140 Å is not the better choice for carbon stars

EMIR is a multiobject intermediate resolution near infrared (1.0-2.5 μm) spectrograph with image capabilities to be mounted on the 10-m Gran Telescopio Canarias (GTC) as one of the first common user instruments. The GTC, located on the Spanish island of La Palma, is due for first light in early 2003. EMIR is being built by a consortium of Spanish

Asteroids in cometary orbits can be defined as minor planets that do not present cometary activity and has orbits with Tisserand parameter T 3 (typical of cometary orbits). The nature and origin of this population is still controversial. Recent dynamical studies claim for a cometary origin (comets that become dormant or dead comets by the growth