Washington, Dec 4 : Astronomers have gathered new evidence with the help of light 'echoes' that has helped solve the mystery of a famous supernova.
According to a report in New Scientist, the mystery was about what kind of a star self-destructed to create the supernova observed by Danish astronomer Tycho Brahe in 1572.
One proposed theory is that a stellar ember called a white dwarf exploded after gorging on material stolen from its neighbour.
Though previous observations had hinted at such a scenario, called a type Ia supernova, the evidence was not strong enough to rule out other possible causes of death, such as the gravitational collapse of a massive star's core.
Now, a team led by Oliver Krause at the Max Planck Institute for Astronomy in Heidelberg, Germany, has spotted telltale signs of a type Ia supernova using the powerful 8.2-metre Subaru telescope in Hawaii.
They studied "light echoes" from the centuries-old supernova, which is the light from the original explosion that reflected off interstellar dust and then headed in our direction.
The light echoes from Tycho's supernova - one of only six recorded in our galaxy in the past 1000 years - were first reported earlier in 2008 by a team led by Armin Rest of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts.
The echoes are around 20 billion times fainter than the light Tycho observed directly in 1572.
Krause's team detected silicon, sulphur and iron signatures in the echoes' spectrum that pointed unequivocally at a type Ia supernova.
According to Andrea Pastorello of Queen's University Belfast and Ferdinando Patat of the European Southern Observatory in Germany, "We are now fully confident that one of the most popular supernova remnants detected in our galaxy was produced by an ordinary type Ia supernova that was first detected more than 400 years ago."