Red explosions: The secret life of binary stars is revealed

January 24, 2013 by Brian Murphy in Astronomy & Space / Astronomy
Hubble space telescope images show an expanding burst of light from a red supergiant star. Credit: NASA/ESA

A University of Alberta professor has revealed the workings of a celestial event involving binary stars that results in an explosion so powerful it ranks close to Supernovae in luminosity.

have long debated about what happens when , two stars that orbit one another, come together in a common envelope. When this dramatic cannibalizing event ends there are two possible outcomes; the two stars merge into a single star or an initial binary transforms in an exotic short-period one.

The event is believed to take anywhere from a dozen days to a few hundred years to complete. Either length is considered to be extremely fast in terms of celestial events. More than a half of all stars in the universe are binary stars. Up until now, researchers had no idea what a common envelope event would look like.

U of A Natalia Ivanova analyzed the physics of what happens in the outer layers of a common envelope. She found that hot and ionized material in the common envelope cools and expands and then releases energy in the form of a bright red of light.

Ivanova linked these theoretically anticipated common envelope outbursts with recently discovered Luminous Red Novae, mysterious transients that are brighter than Novae and just a bit less luminous than Supernovae.

Her research provided both a way to identify common envelope events and explained the generated during the common envelope event.

The research was published in the journal Science.

More information: "Identification of the Long-Sought Common-Envelope Events," by N. Ivanova et al. Science, 2013.

Provided by University of Alberta

"Red explosions: The secret life of binary stars is revealed" January 24, 2013