Telescope trio capture solar wind collisions

Researchers at Trinity College Dublin have taken the highest quality images of Eta Carinae’s stellar winds colliding yet, an event which will aid learning of star evolution and death.

Eta Carinae is a binary star system. Astronomers used three adjustable 1.8m telescopes at the European Southern Observatory (ESO) to combine infrared light that radiated when the stars’ solar winds struck one another.

Professor of Astrophysics at Trinity College Dublin, Jose Groh, said: “These are unprecedented images obtained with the ESO telescopes. The images provide us with a front-row view of how monster stars interact with each other. The heavier star is winning for now, but the faster companion star may change the fate of the system in the future.”

Eta Carinae shines with a power equivalent to five million Suns. Both it and its accompanying star are immersed inside the Homunculus nebula, the results of Carinae’s supernova-like explosion in 1843. The team of astronomers used a new technique called interferometry to obtain their images, which requires the use of multiple telescopes.

Where stellar winds collide in Eta Carinae, gases emit strong amounts of light. After analysis of the light emitted from the star, the researchers were able to understand how the gas moves where the winds collide.

Professor Gerd Weigelt, who led the research, said: “Our dreams came true, because we can now get extremely sharp images in the infrared regime. The ESO interferometer provides us with a unique opportunity to improve our physical understanding of Eta Carinae and many other monster objects."

The astronomers from Ireland also worked alongside researchers from NASA and the Max Planck Institute for Radioastronomy (MPIfR).  The research was published in Astronomy and Astrophysics.