Astronomers were able to observe a galaxy formed in an ancient period, when the universe was young and the stars were a new phenomenon; For viewing the distant galaxy, the researchers used a nearby galaxy as a magnifying lens
Tamara Traubman
Astronomers believe they have had a glimpse of the early universe, at the stages when dark space turned into a place full of stars and spectacular galaxies. This, after they discovered a pale light coming, in their opinion, from a very distant constellation that is in the first stages of its development - a kind of "baby galaxy".
The galaxy is about 200 times smaller than the Milky Way, the galaxy in which our solar system resides. The small constellation contains no more than a million stars, and is about 500 light years in diameter. The Milky Way galaxy, by comparison, contains hundreds of billions of stars and is about 100 light years in diameter.
The researchers estimate that the baby galaxy was created when the universe - whose current age is about 14 billion years - was still a 600 million year old baby, and stars were a new phenomenon. According to the team, the galactic baby is probably an example of one of the building blocks from which today's mature galaxies were formed.
Who invented it, Einstein?
But more than the actual discovery of the baby galaxy, scientists were excited by the means used to discover it. The researchers used a method known as "gravitational lenses", which act as a kind of natural telescope. The method is based on a phenomenon invented by Albert Einstein, but in practice it was only demonstrated in 1979.
Quite similar to the way a glass lens in binoculars bends the light and focuses it on the eye, a gravitational lens is an object with a large mass (like a galaxy), which is in the path of light coming from a distant source to Earth. The large object amplifies the light reaching the Earth, and with the help of the most powerful telescopes on Earth, objects that cannot be discerned in any other way can be observed.
"It's like using the universe itself as a giant telescope," explains Prof. Avishi Dekel, an astrophysicist from the Hebrew University. According to him, this observation method will make it possible to test the validity of existing theories about the formation of galaxies in the early universe.
The constellation in the infant galaxy and the means used to discover it will be described in an article to be published on October 20 in the scientific journal "The Astrophysical Journal." The discovery was made by a team of astronomers from the United States and Europe, led by Richard Ellis, professor of astronomy at the California Institute of Technology.
To discover the new galaxy, Ellis and his colleagues used the natural power of the galaxy cluster, Abell 2218, which is 2 billion light years away from Earth. For the purpose of observation, the astronomers used the Hubble Space Telescope and the Keck Telescope in Hawaii. Next year, the researchers intend to expand the research, and locate at least 10 distant objects.
