COPENHAGEN, Denmark, Nov. 28 (UPI) -- Thanks to the "Eye of Sauron" black hole, researchers have developed a new way to measure large cosmic distances. The supermassive black hole sits in the middle of an active galaxy known as NGC 4151 -- a galaxy that resembles the fiery red evil eye of Peter Jackson's The Lord of the Rings films.
An intimate understanding of how black holes behave is key to the new measurement technique. Astronomers know that nearby gas is constantly being sucked into active black holes. As it's pulled inward, the gas heats up and emits ultraviolet radiation. That heated gas transfers its heat to a ring of dust that orbits the black hole.
"Using telescopes on Earth, we can now measure the time delay between the ultraviolet light from the black hole and the subsequent infrared radiation emitted from the dust cloud," Darach Watson, an astronomer and black hole expert at the University of Copenhagen's Niels Bohr Institute, explained in a press release. "The time difference is about 30 days and because we know the speed of light, we can calculate the real physical distance between the black hole and the encircling dust."
Having a more precise measurement on such a large expanse of space allows relative distances to be measured with more accuracy and less uncertainty.
"We calculated the distance to be 62 million light years," Watson said, in reference to the Eye of Sauron black hole. "The previous calculations based on redshift (a change in the wavelength of the light due to the velocity of the object away from us) were between 13 million and 95 million light years, so we have gone from a great deal of uncertainty to now being able to determine the precise distance."
Researchers say the new technique will also allow a more exact understanding of how fast the universe is expanding, ultimately helping astronomers gauge a more precise age of the universe. The new measurement technique was detailed this week in the journal Nature.