Astronomers came across a unique interstellar structure just 300 light years from Earth. This cloud of gas and dust, called EOS, has long remained invisible to the researchers due to the lack of characteristic radiation, which usually helps to identify such entities.
EOS, named after the Greek goddess dawn, impresses its scale: it is 40 times wider than the full moon in the night sky and almost 3400 times more massive than the sun. This discovery was made possible by the new approach to observation - due to the detection of distant ultraviolet radiation of molecular hydrogen.
Typically, astronomers are looking for molecular clouds by means of carbon monoxide radiation, which is easily fixed in the radio and infrared spectrum. However, EOS almost does not contain this compound, which made it "invisible". For the first time, the structure was recorded due to the fluorescence of hydrogen in the ultraviolet spectrum - the cloud is literally "glowing in the dark", as noted by the leading author of the study Blexley Berkgart.
It helped in this spectrograph, which decomposes the distant ultraviolet light on the components, just as the prism creates a rainbow from ordinary light. Astrophysicist Thomas Gavort, co -author of the study, explained: "The only reason we saw is what we looked in a different spectrum."
EOS opens new horizons to study the interstellar environment, including processes that precede the birth of stars and planets. Melissa McClur's astronomer from Leiden University summarized the meaning of discovering: "It is how to suddenly detect an underground bunker just under its own home."
Scientists believe that this discovery not only changes the understanding of the nature of molecular clouds, but will also become the key to new methods of space exploration around our solar system.
