A group of astronomers from the University of Texas at Austin have discovered that a telescope idea scrapped a decade ago by NASA solves an unsolvable problem for all other current instruments: studying the first stars created In the universe. The results of the work will soon be published in The Astrophysical Journal.
“Throughout the history of astronomy, telescopes have gained in power, allowing us to go further and further in time, and to bring us closer to the creation of the universe, the Big Bang”, affirms the professor Volker Bromm, who has been studying the first stars for decades. “The James Webb space telescope, which is to be launched soon, will allow us to go back to the formation of the first galaxies. “
“Theories want that there was an era before this one, when galaxies did not yet exist, but where the first stars were born, called Population III. This moment of “first light” is beyond the reach of the James Webb Telescope, and therefore an “ultimate” telescope is needed. “
These first stars came to life about 13 billion years ago. They are unique, born from a mixture of hydrogen and helium, and probably tens or even 100 times bigger than the Sun. New calculations made by the main work responsible for the work, scientist Anna Schauer, who works on NASA’s Hubble mission, reveal that an already proposed project, a liquid mirror telescope installed on the surface of the Moon, could study these stars.
Proposed in 2008 by a team led by a researcher at the University of Arizona, the said project was called the Lunar Liquid-Mirror Telescope (LLMT).
NASA evaluated this project 10 years ago, but decided not to go ahead. According to Niv Drory, principal researcher at the McDonald Observatory at the University of Texas at Austin, the science surrounding these early stars did not exist at the time. “This telescope is perfect for that problem,” he says.
The new proposed lunar telescope, dubbed the “Ultimate Size Telescope” by Ms. Schauer, would have a diameter of 100 meters. It would operate autonomously on the surface of the Moon, with a power supply from a solar power plant installed on our natural satellite. The data collected would be retransmitted to an orbiting satellite.
Rather than using glass with a special coating for the mirror, it would be liquid, since the material is lighter, and therefore cheaper, to transport it to the moon. The mirror would in fact be a giant rotating container, covered with a metallic liquid, and therefore allowing the light to be reflected.
The telescope, as a whole, would be stationary, and installed in a lunar crater, possibly at the south or black pole of the moon. To observe the first stars, the device would continuously observe the same area of space, to collect as much light as possible.
“We live in a universe filled with stars,” Mr. Bromm recalls. “It is essential to know how far back the formation of stars in cosmic history goes. The emergence of these stars represents an unavoidable transition in the life of the universe, when the primordial conditions established by the Big Bang gave way to an ever increasing complexity, which eventually led to the appearance of life on planets, and the development of species like ours. “