The Hubble Space Telescope picked up the afterglow of orphaned stars, remnants of several galaxies that were slashed and ripped apart by gravity over the course of about six billion years.
Revealed on Halloween weekend, NASA reported the telescope's time travelling stare picked up the grisly scene. The six galaxies wrecked by gravity and splattered across the universe were located about four billion light years from earth, as Hubble peered into the Abell 2744 galaxy cluster.
Fittingly, the devastated cluster of approximately 500 galaxies is called Pandora's Cluster. Using computer models based on the gravitational dynamics of galaxies, NASA concluded that some of the systems that once housed the orphaned stars were as big as the Milky Way.
The ghost stars are believed to be composed of oxygen, carbon and nitrogen. Because the elements are usually created by first generation starts, scientists believe the ghost stars to be second or third generation stars.
The discovery was an encouraging mile stone in the Frontier Fields program, according to Ignacio Trujillo of The Instituto de Astrofísica de Canarias (IAC) in Santa Cruz de Tenerife, Spain.
"The Hubble data revealing the ghost light are important steps forward in understanding the evolution of galaxy clusters," said Trujillo. "It is also amazingly beautiful in that we found the telltale glow by utilizing Hubble's unique capabilities."
The forensic evidence that remains suggest that the stars were strewn about as their galaxies traveled through or near the center of galaxy clusters, where the tidal force peaks.
The look at the decimated Pandora's Cluster helped evidence the hypothesis that residual light from scattered stars should remain after their homes have been wrecked by gravity. Hubble's high infrared sensitivity allowed astronomers to detect the ghost light, which NASA describes as "extraordinarily dim light."
"The results are in good agreement with what has been predicted to happen inside massive galaxy clusters," said Mireia Montes of the IAC, lead author of the paper published in the Oct. 1 issue of the Astrophysical Journal.
The Hubble Space Telescope is enabling astronomers to peer back farther in time to within roughly 435 million years of the Big Bang. The Frontier Fields program seeks to take Hubble and other telescope to capture "long looks" into 12 regions, six galaxy clusters, of space over the course of three years.
The discovery of the fingerprints left behind by the orphaned stars brings astronomers to a better understanding of the life of stars and galaxies.
