Intermediate mass stars, in their last phases of evolution ("AGB stars"),produce a large number of heavy elements (rich in neutrons), some ofthem radioactive isotopes, such as Rubidium and Technetium. Theseelements are pushed outwards to the surface of the star, and afterwards released into the interstellar medium. Among this type of stars, those least studied have been the more massive ones (between 4 and 8 times the mass of the Sun). Massive AGB stars have been recently identified in our Galaxy and in other nearby galaxies, such as the Magellanic Clouds, thanks to the detection of strong

The distribution of stars in the Hertzsprung-Russell diagram narrates their evolutionary history and directly assesses their properties. Placing stars in this diagram however requires the knowledge of their distances and interstellar extinctions, which are often poorly known for Galactic stars. The spectroscopic Hertzsprung-Russell diagram (sHRD) tells similar evolutionary tales, but is independent of distance and extinction measurements. Based on spectroscopically derived effective temperatures and gravities of almost 600 stars, we derive for the first time the observational distribution of

Happy New Year 2014 from the Instituto de Astrofísica de Canarias (IAC)

With the Canaricam instrument on the Gran Telescopio CANARIAS (GTC), a team of researchers known as ‘Los Piratas’ have caught a system of two galaxies fused together in collision, feeding two black holes at their centres

Astronomers at the IAC have discovered complex patterns of resonances in the discs of spiral galaxies not previously described by theories. Using the GHaFaS 2dimensional spectrometer they have measured the velocities of the density waves in the discs of over a hundred galaxies Within the discs of spiral galaxies there are waves which propagate concentrically in the form of spirals. This is somewhat similar to the waves on the surface of a lake, or the standing waves on the strings of a violin, or on the surface of a drum, to use a musical metaphor. These are the so-called “density waves”

NASA: The Geminids from the Canaries, astronomical image of the day We receive a message from an asteroid in the guise of a meteor shower