Free Astronomy Magazine March-April 2015

32 SOLAR SYSTEM Earth. This suggests that that event oc- curred 70,000 years ago could possibly have visible effects in our vicinities not before a couple of million years, and this helps to get an idea of the im- mensity of the sce- nario in question. But what about stellar passages of a much more dis- tant past, which could have effects in a much nearer future? Fortunately they are not frequent, so much so that Mama- jek's team researchers estimate that an event like the one that had Scholz's Star as protagonist occurs on average every 10 mil- lion years, making highly unlikely an immi- nent comets shower. On the other hand, though, there are certainly a lot of stars (and substars) not yet identified that could orbits (eccentricity close to 1), with an aph- elion similar to the minimum separation between the Sun and the Sholz’s Star, peri- helion between the planets of the solar sys- tem and with periods not much greater than 4 million years. This means that in about 2 million years those nuclei will pass the perihelion point and consequently they too will be at their minimum distance from T he research centres where Mamajek’s team collected the spectra which proved decisive in the characteri- zation of Scholz’s Star: at the top the South Afri- can Astronomical Observatory with the big dome of the SALT tele- scope, and on the left the Chil- ean structure housing the Ma- gellan telescope. [SAAO, NOAO]