Remnants of supernovae in Antarctic ice

2009/03/10 Kortabitarte Egiguren, Irati - Elhuyar Zientzia

• Astronomia

Arab and Chinese astronomers left historical documents on the brightest supernovae in the years 1006 and 1054. Now, researchers from the Japanese center Riken Nishina have discovered the remains of these supernovae in a sample of the ice cores of Antarctica. The image shows the crab nebula from the 1054 supernode.

Ice samples store information about atmospheric components. Thanks to this, they often provide adequate information on the climate of yesteryear. So far the issue has been addressed only at the academic level. According to scientists, ice samples also contain information about supernovae. In fact, gamma rays derived from the nearby supernovae of our galaxy generate a significant impact on the atmosphere, increasing the production of nitrate ions.

In this sense, this group of Japanese researchers analyzed in 2001 a sample of ice collected at the Dome Fuji station in Antarctica peak concentrations of nitrate ions (NO3), corresponding to the supernovae of 1006 and 1054.

In addition, the team of researchers observed cycles of variation in the level of nitrogen oxide of 10 years, due to cycles of solar activity of 11 years.

Image courtesy of: NASA, ESA, J. Hester and A. Loll (Arizona State University)