Astronomers attempting from ages to explain the cause of the puzzling bursts of light in space have finally described the phenomenon as a new kind of exploding star. The mystery which spanned over a decade was finally solved with the help of NASA’s Kepler Space Telescope.
Astronomers had encountered a brief glimpse of this phenomenon in 2012 while reviewing data captured by Kepler. A 10% bump in light from a galaxy 1.3 billion light years away from earth was recorded by Kepler. Scientists were unable to conclude if the flash of light was from an exploding star or a computer glitch. Scientifically known as Fast Evolving Luminous Transients (FELTs), this phenomenon would occur and die down within a month making it hard for space telescopes to capture the event as they record data from a patch of space every few days. The FELT captured in 2015 developed over 2.2 days and faded within 10 days making the discovery of this phenomenon virtually undetectable.
The Kepler Spacecraft aims at exploring exoplanets by taking shots of a single stretch of galaxy for prolonged periods of time. Kepler detects faint changes in a star’s brightness through the transitory stages of planets around them. This calls for the recording of high precision and continuous data. During its mission, Kepler was able to capture the activity of a FELT in remarkable detail. Peter Garnavich, professor and department chair of astrophysics and cosmology physics at the University of Notre Dame and co-author of the study, described the event as “the most beautiful light curve we will ever get for a fast transient.”
Scientists debated on the probable cause of these peculiarly fast events and concluded with a simple theory. The stars “burp” before exploding and don’t generate enough radioactive energy to appear later. As the supernova propels into the gas expelled in the belch, astrophysicists detect a flash. The supernova then vanishes beyond the capture of space telescopes. “Our conclusion was that this was a massive star that exploded, but it had a mass loss — a wind — that started a couple of years before it exploded,” Garnavich described. “A shock ran into that wind after the explosion, and that’s what caused this big flash. But it turns out to be a rather weak supernova, so within a couple of weeks we don’t see the rest of the light.”
Kepler telescope and K2 mission funded by NASA is expected to end in a few months due to fuel exhaustion. 20 more supernova examples have been extracted by Kepler for comprehensive study. Astrophysicists have applauded the contribution of Kepler in the analysis of cosmic phenomena and for propelling the further study of FELTs.