A NASA rocket experiment has revealed that up to half of all stars in the universe are celestial orphans, stars that have drifted away from their parent galaxy.
In a statement released on Wednesday, the National Aeronautics and Space Administration (NASA) revealed that the Cosmic Infrared Background Experiment, or CIBER, has detected an excess of infrared light between galaxies and this is believed to be from orphaned stars. Scientists also observed that the glow produced by these isolated stars is equal to the amount emanating from all the galaxies.
CIBER is composed of a set of telescopes that were primarily designed to analyze extragalactic background light. CIBER was flown on two suborbital rockets launched in 2010 and 2012 and the data were gathered by CIBER during these launches as it took images of the cosmic infrared background.
NASA's Spitzer Space Telescope has earlier detected this background infrared light but the CIBER observations have helped ascertain that it comes from streams of orphaned stars that are too far to be seen individually and not from primordial galaxies.
Data from CIBER's observation show that there is a significant surplus of light beyond what originates from the galaxies and that this infrared background light is too bright and too blue for it to come from the first generation galaxies, said CIBER project principal investigator James Bock.
"The simplest explanation, which best explains the measurements, is that many stars have been ripped from their galactic birthplace, and that the stripped stars emit on average about as much light as the galaxies themselves," Bock said.
The light's blue spectrum provides evidence that the light comes from previously undetected stars that are between galaxies as light from the first galaxies would have given a redder spectrum of colors.
"Infrared Extragalactic background light (EBL) fluctuations have been attributed to primordial galaxies and black holes at the epoch of reionization (EOR) or, alternately, intrahalo light (IHL) from stars tidally stripped from their parent galaxies at low redshift," wrote Bock, and colleagues in their report published in the journal Science on Nov. 7. "The observed fluctuations exceed the amplitude from known galaxy populations, are inconsistent with EOR galaxies and black holes, and are largely explained by IHL emission."
Stars become orphans when galaxies that drift through space periodically collide with each other. During these galactic collisions, some of the stars are stripped away from the galaxies where they were born.