Three decades ago one of the first astronomical satellites designed toobserve X-rays detected a new type of object: it had a much higher luminosity than any star, but much lower than other types of identified sources, such as the nuclei of active galaxies. They were dubbed, in a not very imaginative way, ultraluminous X rays (ULX) sources. Even recently we were still not really sure what they are. In this work, we have managed to solve this mystery and we have found that the mechanism which produces such a large luminosity in the most thoroughly studied ULX is not, as many had hoped, an

Isolated cool white dwarf stars more often have strong magnetic fields than young, hotter white dwarfs which has been a puzzle because magnetic fields are expected to decay with time but a cool surface suggests that the star is old. In addition, some white dwarfs with strong fields vary in brightness as they rotate, which has been variously attributed to surface brightness inhomogeneities similar to sunspots, chemical inhomogeneities  and other magnetooptical effects. Here we describe optical observations of the brightness and magnetic field of the cool white dwarf WD1953-011 taken over

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