3D models reveal details about Eta Carinae

BBC : At 90 solar masses, the primary star in the Eta Carinae system is the most massive star within 10 000 light-years of Earth. The primary used to be more massive. Through a series of explosive outbursts, the most recent of which took place in 1841, the star has lost around 30 solar masses and formed the Homunculus Nebula . The nebula obscures Eta Carinae’s primary and its 30-solar-mass companion star from view, but their behavior can be observed thanks to the winds that blow from the two stars. Every five and a half years, at the stars’ closest approach (a point called the periastron), the smaller star passes through Eta Carinae’s stellar wind. The resulting bow shock releases a blast of x rays. Tom Madura of NASA’s Goddard Space Flight Center in Maryland has created a supercomputer simulation of the interactions. Using a 3D printer, he made grapefruit-sized models of the border regions between the two stellar winds at different points in the orbits. The simulation and the models revealed unexpected features that Madura says are likely due to differences between the stellar winds.