Ant Nebula fired a laser toward Earth
The emission was detected by the Herschel observatory of the European Space Agency and is being regarded by scientists as a precious and rare clue as to what is happening in the center of the "spectacular" Ant's Nebula in the constellation Norma about 3,000 light years from the earth.
When stars the size of our Sun reach the end of their lives, they become dense white dwarfs that eject their outer layers of gases and dust, creating a nebula.
The Ant Nebula is one of those clouds of dust, hydrogen, helium and other ionized gases, and the now-detected laser emission suggests that its original shape - which earned it the informal name - hides a secret about its star's death.
"We have detected a very rare type of emission called a hydrogen recombination laser emission, which is only produced in a very narrow range of physical conditions," explains Isabel Aleman, the lead author of the article describing the discovery. For this type of emissions to occur, a very dense gas (10 thousand times denser than the gas in a typical nebula) is needed next to the star. Now the space regions next to a dead star are usually empty because their material has been ejected out. This means that this is not the case at the center of the Ant Nebula.
Albert Zijlstra, co-author of the article, joins that the only way to keep such a dense gas next to a star is if it is orbiting it on disk and an explanation for having a gas of these in orbit is the existence of a second star , which so far astronomers have not yet been able to observe.
"This study suggests that the unmistakable Ant Nebula, as we see it today, was created by the complex nature of a binary stellar system that influences the shape, chemical properties, and evolution in these final stages of a star's life," says Göran Pilbratt, ESA Herschel project scientist.
The existence of lasers in space was suggested precisely by the astronomer Donald Menzel, the first to observe and classify the Ant Nebula in the 1920s (his official name is Menzel 3, so) well before the discovery and first successful operation, with lasers in laboratories in 1960.
