Universe  ID: 11725

NASA Missions Take an Unparalleled Look into Superstar Eta Carinae

Eta Carinae is a binary system containing the most luminous and massive star within 10,000 light-years. 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. 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.

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. Both produce powerful gaseous outflows called stellar winds, which enshroud the stars and stymy efforts to directly measure their properties. 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. 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.

At 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 observe dramatic changes in the system during the months before and after periastron. 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.

During 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. According to this model, the interaction of the two stellar winds accounts for many of the periodic changes observed in the system. The winds from each star have markedly different properties: thick and slow for the primary, lean and fast for the hotter companion. The primary's wind blows at nearly 1 million mph and is especially dense, carrying away the equivalent mass of our sun every thousand years. By contrast, the companion's wind carries off about 100 times less material than the primary's, but it races outward as much as six times faster.

The images and videos on this page include periastron observations from NASA's Rossi X-ray Timing Explorer, the X-Ray Telescope aboard NASA's Swift, the Hubble Space Telescope's STIS instrument, and computer simulations. See the captions for details.


For More Information



Scott Wiessinger (USRA): Producer
Thomas Madura (ORAU): Scientist
Theodore Gull (NASA/GSFC): Scientist
Thomas Madura (ORAU): Animator
Brian Monroe (USRA): Animator
Scott Wiessinger (USRA): Narrator
Scott Wiessinger (USRA): Video Editor
Francis Reddy (Syneren Technologies): Writer
Scott Wiessinger (USRA): Writer
Please give credit for this item to:
NASA's Goddard Space Flight Center. However individual items should be credited as indicated above.

Short URL to share this page:


Data Used:
Hubble Space Telescope
Note: While we identify the data sets used in these visualizations, we do not store any further details nor the data sets themselves on our site.

This item is part of these series:
Narrated Movies
Astrophysics Animations
Astrophysics Simulations
Astrophysics Stills
Astrophysics Features

Goddard TV Tape:
G2015-001 -- Eta Carinae Inner Workings

SVS >> Music
SVS >> Simulation
SVS >> X-ray
SVS >> Hubble Space Telescope
SVS >> Astrophysics
SVS >> Edited Feature
SVS >> Space
SVS >> Swift
SVS >> Binary Star
DLESE >> Narrated
SVS >> Suzaku
SVS >> Star
SVS >> Nebula
NASA Science >> Universe