Using data from NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton spacecraft, astronomers have created a captivating time-lapse video showcasing a stellar eruption that occurred approximately 180 years ago. The video, which combines observations from 1999 to 2020, offers a glimpse into the history of the explosive event known as Eta Carinae.
Eta Carinae is a well-known star system featuring two massive stars. Scientists estimate that one of the stars is around 90 times more massive than the sun, while the other is approximately 30 times more massive. The remarkable explosion, fittingly named the “Great Eruption,” originated from Eta Carinae and is believed to be the result of a merger between two stars that belonged to a triple star system.
The aftermath of this cosmic collision was witnessed on Earth during the mid-19th century, and the new video demonstrates how the eruption has continued to expand at astonishing speeds of up to 4.5 million miles per hour. The ejected material from the explosion, equivalent to 10 to 45 times the mass of the sun, formed the Homunculus Nebula—an impressive pair of spherical gas clouds surrounding the two massive stars.
In the video, the Homunculus Nebula appears as a bright blue cloud emitting high-energy X-rays, which are generated by the two closely situated massive stars. Surrounding the nebula is a vibrant orange ring of X-ray emissions that appear to grow and expand over time. Notably, the video and summed image captured by Chandra’s observations reveal previously unknown details about Eta Carinae’s eventful history, including the rapid expansion of the ring and the presence of a faint X-ray shell outside of it.
Astronomers have determined that this faint X-ray shell, outlined in the observations, shares a similar shape and orientation with the Homunculus Nebula. This suggests a common origin for both structures. By studying the motion of gas clumps, researchers deduced that the stellar material was expelled from Eta Carinae between the years 1200 and 1800, predating the observed Great Eruption in 1843. As the blast wave spread through space, it encountered interstellar material, heating it and giving rise to the bright X-ray ring. However, the blast wave has now surpassed the ring, resulting in a fading X-ray brightness from Eta Carinae.
These findings, published in a 2022 study in the Astrophysical Journal, shed light on the expansion of Eta Carinae and provide valuable insight into its past. Michael Corcoran from NASA’s Goddard Space Flight Center in Maryland, who led the study, emphasizes the significance of the faint X-ray shell, noting that it reveals an integral component of Eta Carinae’s history that would have otherwise remained unknown.
– NASA’s Chandra X-ray Observatory
– ESA’s XMM-Newton spacecraft