The stars and planets are born inside swirling clouds of cosmic gas and dust which are full of hydrogen and other molecular ingredients. On Monday, astronomers revealed the discovery of the known cloud closest to the earth, a colossal drop in the shape of a potential for stars formation.
Named EOS, after the Greek goddess of the dawn, the cloud was found hidden some 300 light years from our solar system and is as wide as 40 of the moons of the earth have aligned themselves in the sky. According to Blakesley Burkhart, astrophysicist at Rutgers University, it is the first molecular cloud to be detected using the fluorescent nature of hydrogen.
“If you were to see this cloud on the sky, it's huge,” said Dr. Burkhart, who announced the discovery With colleagues from the Revue Nature Astronomy. And “he literally shines in darkness,” she added.
The identification and study of clouds like EOS, in particular according to their hydrogen content, could reshape the understanding of astronomers of the quantity of equipment in our galaxy available to produce planets and stars. This will also help them measure the rates of fuel creation and destruction which can lead such training.
“We are, for the first time, see this previously hidden hydrogen reservoir which can train stars,” said Thavisha Dharmawardenarda, astronomer at New York University which is the author of the study. After EOS, she said, astronomers “hope to find much more” such heavy clouds of hydrogen.
Molecular hydrogen, which consists of two hydrogen atoms linked together, is the most abundant material in the universe. The stellar nurseries are full of them. But it is difficult to detect the soil molecule because it shines in Lointre-Utraviolet wavelengths which are easily absorbed by the earth's atmosphere.
Carbon monoxide is easier to spot, a molecule composed of a carbon atom and an oxygen atom. Carbon monoxide radiates light in longer wavelengths which can be detected by radio observatories on the surface of the earth, a more conventional technique to identify the cloud formation clouds.
EOS, as immense as it may be, has escaped detection for so long because it contains so little carbon monoxide.
Dr. Burkhart noticed the cloud while studying data aged about 20 years from the distant imaging spectrograph, or Fims, an instrument on a Korean space satellite. She spotted a structure in molecular hydrogen data in a area of ​​space where she thought that no molecular cloud was present, then associated with Dr Dharmawardenana to investigate more.
“At this stage, I had known just about all the molecular clouds by name,” said Dr. Dharmawardena. “This structure, I didn't know at all. I couldn't put it.”
Dr. Dharmawardenaa counted the discovery with three -dimensional cards of interstellar dust between the stars in our galaxy. These cards were built with recently retired GAIA space telescope. EOS “was very clearly described and visible,” she said. “It is this magnificent structure.”
John Black, astronomer at the Chalmers University of Technology in Sweden who was not involved in the work, congratulated the technique used to reveal the EO.
“It's really wonderful to be able to see molecular hydrogen directly, to draw the contours of this cloud,” said Dr. Black. Compared to carbon monoxide, hydrogen shows “a more real image of the form and size” of EOS, he added.
Using the molecular hydrogen content, astronomers estimated that the mass of EOS was about 3,400 times that of our sun. It is much higher than the estimate calculated from the quantity of carbon monoxide present in the cloud – as little as 20 times the mass of our sun.
Similar measures of carbon monoxide could very well underestimate the mass of other molecular clouds, said Dr. Burkhart. This has important implications for the training of stars, she added, because larger clouds form more massive stars.
A follow -up study D'EOS, which has not yet been evaluated by peers, found that the cloud had not formed stars in the past. But the question remains whether it will start to produce stars in the future.
Dr. Burkhart works with a team of astronomers to conceptualize a NASA spacecraft called EOS, which has also inspired the name of the newly discovered cloud. The proposed space telescope would be able to map the molecular hydrogen content of the clouds through the galaxy, including its homonym.
Perhaps such a mission would find more hidden clouds or revise knowledge of the ability of stellar mists known to merge their equipment into stars and planets.
“We don't really know how stars and planets are formed,” said Dr. Burkhart. “If we are able to directly look at molecular hydrogen, we can say how the birthplaces of stars are formed – and also how they are destroyed.”
