Hubble’s latest image of Eta Carinae isn’t just its highest resolution image yet of the double star system. The ultraviolet image also shows a special view of the expanding gases glowing in red, blue, and white.
Eta Carinae In Ultraviolet
Violent eruptions are quite common for Eta Carinae. The two stars of the binary are quite massive with masses that are 90 and 30 times more than the sun, and the larger of the two is unstable and close to death. When the so-called Great Eruption was observed in 1838, Eta Carinae became so bright that by 1844 it was the second brightest star in the sky, bested only by Sirius. Eventually, however, the stars dimmed and can no longer be seen by the naked eye.
However, the latest Hubble images of Eta Carinae show the double stars still active with violent mass ejections. The stunning ultraviolet images were captured by Hubble’s Wide Field Camera 3, revealing the light from nitrogen-rich filaments seen in red, and the blue magnesium in places that it was not observed before.
“Most of the emission is located where we expected to find an empty cavity. This extra material is fast, and it ‘ups the ante’ in terms of the total energy of an already powerful stellar blast,” said Nathan Smith, lead investigator of the Hubble program.
The ‘Great Eruption’
It is unclear what caused the Great Eruption observed nearly 200 years ago, and it is the subject of speculation and debate. One recent theory is that Eta Carinae actually began as a triple system, and that the Great Eruption was actually a result of the primary star devouring one of the two other stars. While plausible, the real reason behind the Great Eruption remains a mystery.
For now, what experts know is how Eta Carinae’s violent eruptions will end, which is with a supernova that will likely surpass the brightness of the Great Eruption. According to NASA, this may have happened already, but it will take 7,500 years for the show to reach the Earth.
