Astronomers identify 'most distant galaxy' ever discovered

By Jeyhun Aliyev

ANKARA (AA) - Astronomers revealed "the most distant galaxy" discovered to date, which existed just 330 million years after the Big Bang -- the enormous cosmic explosion that scientists believe gave birth to the universe -- according to an independently run online science news outlet on Thursday.

"Its faint light, stretched by the expansion of the Universe, had to travel 13.5 billion light-years to reach us, here on Earth," said the ScienceAlert website.

Identified as a "glowing red object in the early Universe," the scientists have named the galaxy HD1, noting that it represents "something of a mystery."

"Scientists are not entirely sure what the galaxy is: whether it's a starburst galaxy, positively roiling with star formation, or a quasar, with a massive, active supermassive black hole at its center," the statement added.

Fabio Pacucci, astrophysicist of the Harvard & Smithsonian Center for Astrophysics, said that commenting about the nature of a source so far away can be "challenging."

"It's like guessing the nationality of a ship from the flag it flies, while being faraway ashore, with the vessel in the middle of a gale and dense fog. One can maybe see some colors and shapes of the flag, but not in their entirety. It's ultimately a long game of analysis and exclusion of implausible scenarios," he said.

ScienceAlert website underlined that detecting objects from the early Universe is "extremely difficult," noting that even quasars, the brightest objects in the whole cosmos, are dimmed across the vast reaches of space-time, to the point that the most powerful telescopes struggle to pick up their light.

HD1 was discovered as part of a survey to find out galaxies at the beginning of the Universe, while the survey included four powerful optical and infrared telescopes -- the Subaru Telescope, the VISTA Telescope, the UK Infrared Telescope, and the Spitzer Space Telescope.

"Between them, they racked up over 1,200 hours of observing time, peering into the Cosmic Dawn to search for light in the early Universe," Pacucci said.

He went on to say that the very first population of stars that formed in the Universe were "more massive, more luminous and hotter than modern stars."

"If we assume the stars produced in HD1 are these first, or Population III, stars, then its properties could be explained more easily. In fact, Population III stars are capable of producing more UV light than normal stars, which could clarify the extreme ultraviolet luminosity of HD1," Pacucci added.

Astronomer Yuichi Harikane of the University of Tokyo in Japan in a statement highlighted that working to find HD1 out of over 700,000 objects was "very hard."

"HD1's red color matched the expected characteristics of a galaxy 13.5 billion light-years away surprisingly well, giving me a little bit of goosebumps when I found it," Harikane noted.