Free Astronomy Magazine November-December 2016

standing of how these kind of ex- tremely high mass stars lose mass as they evolve. Team member Die- ter Schertl (MPIfR) looks forward: “The new VLTI instruments GRA- VITY and MATISSE will allow us to get interferometric images with even higher precision and over a wider wavelength range. This wide wavelength range is needed to de- rive the physical properties of many astronomical objects.” nity to improve our physical under- standing of Eta Carinae and many other key objects” , says Gerd Wei- gelt. In addition to the imaging, the spectral observations of the collision zone made it possible to measure the velocities of the in- tense stellar winds. Measurements were done through the Doppler effect. Astronomers use the Dop- pler effect (or shifts) to calculate precisely how fast stars and other astronomical objects move toward or away from Earth. The move- ment of an object towards or away from us causes a slight shift in its spectral lines. The velocity of the motion can be calculated from this shift. Using these velocities, the team of astronomers were able to produce more accurate computer models of the internal structure of this fascinating stellar system, which will help increase our under- SPACE CHRONICLES 33 n