Researchers, who measured the distance to a pair of stars in a nearby galaxy, said they’ve identified an error in the Hubble constant that suggests the universe is 15% larger and 15% older than previously thought.
The team of scientists, led by Alceste Bonanos of the Carnegie Institution of Washington, used light, velocity, and temperature measurements to determine the intrinsic luminosity of two stars in the Triangulum Galaxy, which eclipse one another every five days. Using the direct measurements, the scientists calculated the galaxy’s distance as 3.14 million light years from Earth – a distance about a half million light years farther than had been previously believed.
Distance measurements across the vastness of space are difficult and imprecise. Scientists have developed a system based on a series of independent measures and certain scientific constants, like the Hubble constant, a measure of the expansion rate and age of the universe. It was this standard procedure that gave the scientists a distance measurement 15 percent short of what they were able to observe directly using data from telescopes, including the 10-meter Keck-II telescope in Hawaii.
“This is the farthest distance that anyone has been able to measure directly,” team member Norbert Przybilla at the University of Erlangen-Nuremberg, Germany, told New Scientist. “It’s the cutting edge of what can be done with these telescopes.”
The 15 percent divergence between the measured distance and the calculated distance to the nearby galaxy has implications for the universe’s size and age.
Recent estimates by some scientists for the age of the universe have put the so-called Big Bang at 13.7 billion years in the past. Adding 15 percent to that estimate would suggest an age for the cosmos of 15.8 billion years.
“Our result hints that there may be something interesting happening with the Hubble constant,” said Przybilla. “We need to follow this up with more measurements.”