A Variable Star Breaks Conventional Cosmological Theories Right Before Our Eyes.
According to Science Alert, the monitoring results of a variable star named M31-2014-DS1 in the Andromeda Galaxy, the giant neighbor of the Milky Way, have completely baffled scientists.
Astronomers observed M31-2014-DS1 brightening in the mid-infrared (MIR) range in 2014.
For the next 1,000 days, its brightness remained constant. However, in the subsequent 1,000 days between 2016 and 2019, it dimmed significantly.
The giant star within the Andromeda galaxy may have suddenly turned into a black hole – (AI Illustration: ANH THƯ).
This is a variable star, meaning its brightness changes over time, but this behavior cannot be explained by typical models.
By 2023, things became even stranger as it could not be detected in deep optical and near-infrared observations. It appeared to have died, but not in a conventional manner.
Widely accepted theories suggest that a massive star like M31-2014-DS1 would undergo a powerful supernova explosion — causing it to flash brightly — before collapsing into a compact neutron star.
This neutron star might also explode again at the end of its life and form a stellar-mass black hole.
M31-2014-DS1 was born with an initial mass of about 20 times that of the Sun and reached its final nuclear burning stage with a mass of around 6.7 times that of the Sun.
Therefore, if it exploded, scientists would expect to see that explosion very clearly.
New observations show that where it once resided, something is now surrounded by a newly ejected dust shell, similar to what occurs after a supernova.
So what could prevent a star from exploding into a supernova, even if it has the right mass to do so?
A supernova is an event where the density inside the core collapses to such an extent that electrons are forced to combine with protons, resulting in both neutrons and neutrinos, known as “ghost particles.”
This process is called neutronization and produces a powerful explosion known as a neutrino shockwave.
Neutrinos are referred to as “ghost particles” because they are a form of electrically neutral particles that rarely interact with anything around them.
However, in the dense core of a star, the density of neutrinos becomes so great that some accumulate energy from the surrounding stellar material, heating it up and creating shock waves.
These neutrino shocks always fade, but sometimes they can reignite, possibly due to the neutrino emissions providing energy. Upon reignition, they cause an explosion and eject the outer layers of the supernova.
In the case of M31-2014-DS1, the neutrino shock did not reignite, leading to what is termed a failed supernova.
“This implies that most of the star’s mass collapsed into the core, exceeding the maximum mass of a neutron star and forming a black hole,” explained Dr. Kishalay De from the Kavli Institute for Astrophysics and Space Research at the Massachusetts Institute of Technology (MIT).
It is estimated that up to 98% of the star’s mass collapsed, and in its place now lies a black hole with a mass 6.5 times that of the Sun.
This discovery has validated the hypothesis that some massive stars may skip the supernova stage and directly transform into black holes, a theory that had been previously questioned with N6946-BH1, an exceptionally bright star that vanished suddenly in 2015.
