Most Luminous Superstar Eta Carinae Reaches Earth as Cosmic Rays

Most Luminous Superstar Eta Carinae Reaches Earth as Cosmic Rays

A new study has found out that the Superstar Eta Carinae, most luminous and massive stellar system, may reach Earth as cosmic rays. To discover it, astronomers used the data from NASA’s NuSTAR space telescope.

“We know the blast waves of exploded stars can accelerate cosmic ray particles to speeds comparable to that of light, an incredible energy boost,” said Kenji Hamaguchi, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and the lead author of the study. “Similar processes must occur in other extreme environments. Our analysis indicates Eta Carinae is one of them.”

According to astronomers the cosmic rays with energies greater than 1 billion electron volts (eV) come to us from beyond our solar system. Since these particles such as electrons, protons and atomic nuclei carry an electrical charge. This scrambles their paths and masks their origins.

What we know about Superstar Eta Carinae?

  • Eta Carinae is famous for a 19th century outburst that briefly made it the second-brightest star in the sky.
  • The star is located about 7,500 light-years away in the southern constellation of Carina.
  • The system contains a pair of massive stars whose eccentric orbits bring them unusually close every 5.5 years.

“Both of Eta Carinae’s stars drive powerful outflows called stellar winds,” said team member Michael Corcoran, also at Goddard. “Where these winds clash changes during the orbital cycle, which produces a periodic signal in low-energy X-rays we’ve been tracking for more than two decades.”

“We’ve known for some time that the region around Eta Carinae is the source of energetic emission in high-energy X-rays and gamma rays”, said Fiona Harrison, the principal investigator of NuSTAR and a professor of astronomy at Caltech in Pasadena, California. “But until NuSTAR was able to pinpoint the radiation, show it comes from the binary and study its properties in detail, the origin was mysterious.”

NuSTAR is a Small Explorer mission led by Caltech and managed by JPL for NASA’s Science Mission Directorate in Washington.

 

Source: NASA