The pace of expansion of our universe may not be as fast as we have believed, according to a new study.
The study, which was conducted by a team of astronomers from the University of Arizona, showed that there exist certain types of exploding stars or supernovae that are more diverse than earlier thought. The results have implications for major cosmological queries, like at what acceleration is our universe expanding since the major Big Bang phenomenon.
The astronomers found that type Ia supernovae fall into different populations. So far, type Ia supernovae have been considered very uniform and this is the reason why the cosmologists have used them as cosmic beacons in order to plumb the universe’s depths.
The results are analogous to sampling a 100-watt light bulbs selection at the hardware store and uncovering that they differ in brightness.
Peter A. Milne, study lead author, said that they discovered the variance is not random. However, they lead to split of Ia supernovae into two groups, where the minority group near them are in the majority at large distances and thus when our universe was younger.
The latest discovery has thrown light on the currently approved view of the universe that is expanding at an unexpectedly faster rate, which is pulled apart by a badly understood force known as dark energy.
Concluding the study, the authors said that some of the acceleration of the universe reported so far can be clearly explained by the differences in color between the two supernovae groups, which will leave less acceleration than reported initially. In turn, this would need lesser dark energy than it was currently assumed.
The findings of the study were published in the Astrophysical Journal.
