New astronomical software system helps unveil two celestial explosions

Washington – A team of researchers have used a novel astronomical survey software system — the intermediate Palomar Transient Factory (iPTF) — to link a new stripped-envelope supernova, named iPTF13bvn, to the star from which it exploded.

The iPTF team including Carnegie’s Mansi Kasliwal and John Mulchaey, also pinpointed the first afterglow of an explosion called a gamma-ray burst that was found by the Fermi satellite.

Their findings reflect the first time a star has been linked to the resulting explosion for this type of supernova, called Type Ib.

The discovery offers very important answers about how this supernova type is formed, a problem that has eluded scientists for years.

About a third of all supernovae of massive stars are of the Type Ib.

There are several theoretical models as to how they are formed, including mass transfer due to solar winds between a pair of binary stars.

It is thought that the progenitors are either massive helium stars or a type of very large, very hot stars known as Wolf Rayet stars.

“Pinpointing a progenitor star at exactly the same location as a Type Ib supernova was the best way to test the theories about the genesis of this type of explosion,” Kasliwal said.

“Now we need to patiently wait for the supernova to fade away and see if the star disappears,” the researcher added.

The new supernova was discovered in mid-June. No explosive light source was detected even a day earlier. Baby pictures of this one-day-old supernova were promptly taken by telescopes in the radio, X-ray, ultraviolet, and infrared wavelengths, providing vital clues about its origins.

Detailed analysis of different types of observations of the supernova confirmed that it was, indeed, a Type Ib, and that it reached full luminosity two weeks from its initial explosion.

The team detected a progenitor candidate for the explosion in Hubble Space Telescope imaging, linking the supernova to its predecessor star. Future imaging will help identify whether this progenitor was a single star, a binary star, or a star cluster.

The team thinks that their observations are consistent with the progenitor having been a Wolf Rayet star. If so this would be a breakthrough discovery.

The findings are set to be published by The Astrophysical Journal Letters.