Go to a dark place and look to the night sky. How many stars you can count? This is an ancient question which can be traced back at least to the classic Greek philosophers. However, no matter how dark your sky is, the stars you are seeing are all related to our home, the Milky […]
TW Hydrae is a peculiar star. Although it is not bright enough to be visible to the unaided eye, it is relatively close to us, just 180 light-years away, and this makes it the closest T Tauri star in the sky. A T Tauri star is a solar system being born, they are still to […]
During the last year, a longtime forgotten controversy was reactivated by a very interesting paper written by J. Polchinski and his collaborators, in which they questioned whether the so called black hole complementarity principle is a good solution to the apparent information paradox of quantum gravity. This is a question that attracted a lot of […]
NGC1365 is a beatiful galaxy. It is big and bright enough to be observed with a medium-sized amateur telescope. Sometimes mis-located at the southern constellation of Eridanus, it is indeed located in the smaller Fornax constellation and it is one of the most notable peers in a famous galaxy cluster. Being one third of the […]
Newton’s theory of gravitation assumes that the speed of gravity is infinite and the gravitational interaction is instantaneous. However, Einstein’s theory postulates that it is exactly equal to the speed of light. A team of Chinese physicists lead by Tang Ke Yun, at the Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China […]
Where is the half of the ordinary matter in the universe not observed yet? Computer simulations of cosmological galaxy formation predict the existence of large intercluster filaments of hot and low-density gas, the so-called cosmic web. For the first time, ESA’s Planck satellite has observed one of such filaments in the merging cluster pair A399-A401 […]