Greek Scientists Shed Light on How Stars are Formed

Αssociated Press

(AP Photo/Scott Heppell, File)

Greek scientists from the University of Crete and the Foundation for Research and Technology (FORTH) made an important step forward in understanding the process of how stars are born.

For the first time internationally, Greek researchers managed to three-dimensionally "map" an interstellar molecular cloud of gases and dust, a region where new stars are born, as they discovered that its magnetic field vibrates like a bell. They thus opened the way for solving one of the greatest mysteries in astrophysics: What determines the number and type of stars and planets created in our galaxy.

The discovery, which was published in the journal Science, was the core of Dr. Aris Tritsis' doctoral thesis, which he completed at the Department of Physics of the University of Crete under the supervision of Professor Costas Tassis. It was based on the theoretical and experimental studies of the two researchers at the University of Crete and FORTH, as well as data from the ESA Herschel Space Mission.

"The process of astrogenation remains one of the biggest unresolved problems in astrophysics," Tassis said to the Athens-and Macedonian News Agency. "We know that stars are born in interstellar gas clouds of 'astronomical' dimensions, but what how exactly we get out from clouds to stars like our sun and the planets is still a mystery. What determines if a cloud will make many small stars or a few big ones? What percentage of the cloud gas will be converted into stars and how much will be recycled?"

The natural processes that determine the process of astrogenation leave their imprint on the three-dimensional shape of these clouds. These trails could help scientists decrypt the natural processes of the birth of the stars. But this has so far been impossible, as even the most advanced telescopes can only map the two-dimensional projection of clouds in the sky and not their three-dimensional structure.

This is precisely the achievement of the Greek researchers. They studied the case of Musca, a large isolated cloud, visible from the southern hemisphere of the Earth, which in the sky looks resembles a narrow cylinder like a needle. The cloud, consisting mainly of hydrogen molecules and located 570 light years away from the Earth under the Southern Cross constellation, is about 27 light years long and 20 light years deep, according to the researchers.

Greek scientists have discovered that Musca's entire magnetic field is vibrating, generating sounds whose frequencies reveal its true three-dimensional shape, just like the frequencies of a musical instrument: in the same way that a small a big drum makes a different sound than a large one. Using roughly the same method for the cloud, they calculated that its width is comparable to the visible length of the cloud in the sky.