Curated by RSF Research Staff
Astronomers have found a phoenix star
On 2014 September astronomers discovered iPTF14hls, a supernova classified on 2015 January 8, as a supernova of type II-P. In the case of iPTF14hls, researchers have found a very surprising energetic emission a few hundred days after its terminal explosion. At this moment, it is still unclear what is powering this phenomenon and how a dead star could rise literally from its ashes. The energy source could come from the interaction of the ejecta with previously ejected shells.
Supernovae are these exploding stars, transient objects. The type II are characterized by hydrogen emission and more intense light curve shapes (the graph of luminosity as a function of time). In a type II-P supernova, the core of a massive star collapses to create a neutron star, sending a shock wave through the outer hydrogen-rich envelope and ejecting the envelope. The shock ionizes the ejecta, which later expand, cool and recombine.
Studying the light curve provides crucial information that can help astronomers understand processes at work and identify specific categories (or classes) of stellar events. Light curve shapes are attributed to set of objects and their dynamic also give information regarding the orbital period.
"But not too long ago it was faster to identify short-lived celestial phenomena than it was to classify them and determine what they could teach us.
The massive star at the origin of iPTF14hls probably experienced multiple energetic eruptions over the last decades of its life. The observed characteristics are consistent with a shell of several tens of solar masses ejected a few hundred days before a terminal explosion. However, astronomers are not sure yet about their model and other mechanisms for the violent ejection of mass in massive stars may be involved in this very particular astronomical event.
Continue reading at: https://phys.org/news/2017-11-star-survived-years.html