Even stars have a life cycle. Less massive stars, like the Sun, end their lives blowing away most of their mass in an intense stellar wind, which eventually, and briefly, is surrounded by a beautifully coloured cloud, a so-called planetary nebula. During this process, dying stars enrich the interstellar medium with chemical elements, which will participate in a new generation of stars, planets, and in at least one case, life. The outer parts of planetary nebulae contain valuable information on the important mass loss process. A research team from Potsdam has just published groundbreaking work deciphering the details of this phase of stellar evolution. Their exploration of the halos of five planetary nebulae has been possible thanks to the exceptional capabilities of the PMAS spectrograph that is attached to the Calar Alto 3.5 m telescope…

One of the teams of winners of the 2007 edition of ESO contest "Catch a Star" enjoyed their prize in June 2008: a four days visit to Calar Alto Observatory offered by the Spanish Council for Scientific Research (CSIC). During their stay at these Spanish-German facilities placed in South-Eastern Spain, they had the opportunity to learn how a modern observatory is organised, how do modern telescopes and instruments work, and how real astronomical observations are performed...

  Calar Alto Academy was initiated in 2007 with the aim to give students from different Spanish universities the chance to perform professional observational work at Calar Alto Observatory. The second edition of this innovative educational project has increased the number of participating universities and has almost doubled the quantity of visiting students, in a significant step towards the consolidation of this undergraduate and graduate school of observational astronomy...

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...