According to this model, the interaction of the two stellar winds accounts for many of the periodic changes observed in the system. These include X-ray flares, followed by a sudden decline and eventual recovery of X-ray emission the disappearance and re-emergence of structures near the stars detected at specific wavelengths of visible light and even a play of light and shadow as the smaller star swings around the primary.ĭuring the past 11 years, spanning three periastron passages, the Goddard group has developed a model based on routine observations of the stars using ground-based telescopes and multiple NASA satellites.

Astronomers observe dramatic changes in the system during the months before and after periastron. While the properties of its smaller, hotter companion are more contested, Goddard's Ted Gull and his colleagues think the star has about 30 solar masses and emits a million times the sun's light.Īt closest approach, or periastron, the stars are 140 million miles (225 million kilometers) apart, or about the average distance between Mars and the sun. Astronomers have established that the brighter, cooler primary star has about 90 times the mass of the sun and outshines it by 5 million times. Both produce powerful gaseous outflows called stellar winds, which enshroud the stars and stymy efforts to directly measure their properties. Located about 7,500 light-years away in the southern constellation of Carina, Eta Carinae comprises two massive stars whose eccentric orbits bring them unusually close every 5.5 years. New findings include Hubble Space Telescope images that show decade-old shells of ionized gas racing away from the largest star at a million miles an hour, and new 3-D models that reveal never-before-seen features of the stars' interactions. A long-term study led by astronomers at NASA's Goddard Space Flight Center in Greenbelt, Maryland, combined data from NASA satellites, ground-based observing campaigns and theoretical modeling to produce the most comprehensive picture of Eta Carinae to date. Eta Carinae is a binary system containing the most luminous and massive star within 10,000 light-years.

1024x576 image converter