A massive star exploded in our Galaxy more than 11 000 years ago. The event, now known as "Cassiopeia A supernova", could have been seen from Earth around 1680, but seemingly almost everybody in our planet missed the show. But now, an international scientific team has performed an impressive work of celestial archaeology: they have used the interstellar dust as a look-back mirror that allowed them to receive news from the past. Some light from that explosion was reflected by dust clouds placed at some distance from the dying star, and this reflection has been detected and analysed. This way, modern astronomy witnesses the cataclysmic display that our ancestors did not study, for some reason, in the 17th century. Calar Alto staff, telescopes and instruments have contributed to this finding...

Astronomers have confirmed the binary nature of OJ 287, a very massive black hole in the centre of a very distant galaxy in the constellation of Cancer. A central black hole, with a mass equal to 18 billion times that of the Sun, is orbited by a smaller one, and the interaction of the system with its surroundings produces brightness changes that allow astronomers to study the evolution of the orbit. This evolution is dominated by one of the most intriguing predictions of Einstein's theory of General Relativity: the emission of gravitational waves. This outstanding confirmation of Einstein's centennary theory has been recently published in the journal Nature, and Calar Alto staff, telescopes and instruments have contributed to the discovery...

The ALHAMBRA project, whose Principal Investigator is Professor Mariano Moles (Astrophysical Institute of Andalusia, Granada) and is performed with the 3.5 m telescope of Calar Alto Observatory (Almería), has obtained an impressive image of the outstanding spiral galaxy M74, an object placed at approximately 30 millions of light-years from Earth, in the constellation Pisces...