Double Star
Broschiertes Buch

Double Star

Versandkostenfrei!
Versandfertig in 6-10 Tagen
29,99 €
inkl. MwSt.
PAYBACK Punkte
15 °P sammeln!
In observational astronomy, a double star is a pair of stars that appear close to each other in the sky as seen from Earth when viewed through an optical telescope. This can happen either because the pair forms a binary system of stars in mutual orbit, gravitationally bound to each other, or because it is an optical double, a chance alignment of two stars in the sky that lie at different distances. Binary stars are important to stellar astronomers as knowledge of their motions allows direct calculation of stellar mass and other stellar parameters. Since the beginning of the 1780s, both profess...