A strange yellow dwarf explodes in a supernova in ways never seen before "pushing the boundaries of what is physically possible," to quote the scientists who have observed it.
A team of the NASA tracked the enigmatic ball of gas for 30 months before it exploded in a supernova 35 million light-years from Earth.
Abnormal behavior of the supernova
What should have been routine behavior for this star has turned into something unexpected. Unlike all of those seen so far, this supernova lacked a layer of hydrogen around it before exploding.
It's something scientists didn't know was possible.
"We haven't seen this scenario before," says the researcher Charles Kilpatrick, who conducted the study published in the monthly newsletter of the Royal Astronomical Society.
To explode without hydrogen, a star would have to be extremely blue and very, very hot.
We looked at every single stellar pattern that could explain a star like this. And every single model requires the star to have hydrogen, which this supernova did not have.
Charles Kilpatrick, Northwestern University
An "almost normal" supernova: the hypotheses
During its observation that began two years before the explosion, the supernova located in the spiral galaxy NGC 4666 seemed "normal".
NASA scientists have formulated some hypotheses about the origins of this circumstance.
Hypothesis 1: this star ejected its hydrogen several decades before exploding, due to catastrophic eruptions that took away its mass before an explosion.
Hypothesis 2: a minor star may have stripped hydrogen from the supernova source.
One day we will understand
Unfortunately, it will be a long wait for scientists to investigate further. The light from the supernova explosion is too intense.
"In four or five years," says Kilpatrick, "we will be able to find out more about what happened."
