Astronomers have observed a never-before-seen phenomenon known as a micronova. This event is caused by the buildup of materials on the surface of white dwarfs, leading to a thermonuclear explosion. The discovery was made by astrophysicist Simone Scaringi of Durham University in the UK, who says “this is the first time we have discovered and identified what we call a micronova“.
“This phenomena casts doubt on our comprehension of how fusion explosions in stars take place. We believed we had a thorough understanding of thermonuclear explosions in stars, but this new information offers a completely different perspective on human nature “.
Close binary systems with white dwarfs have the potential to produce thermonuclear explosions. The core of a white dwarf, which forms after a main sequence star runs out of fuel and expels its outer materials, is what is known as a “dead” star. Black holes and neutron stars are two examples of similar stars that frequently belong to distinct mass classes.
It is quite dense inside this crushed core. A sphere the size of Earth surrounds white dwarfs, which have masses 1.4 times greater than that of the sun. Binary systems contain many of them.
The binaries are close enough in a small number of instances—about 10 have been found in the Milky Way—for the white dwarf to extract matter from the companion.
The smaller, denser, and more massive white dwarf will draw matter—mostly hydrogen—from the companion star as the two stars orbit one another. On the white dwarf’s surface, this hydrogen gathers and heats up.
Periodically, the mass builds up to such a level that the pressure and temperature at the layer’s base are sufficient to set off a thermonuclear explosion, which violently expels extra material into space. And Scaringi and his team have discovered a singular phenomenon called micronovae.
Data from the TESS exoplanet-hunting telescope have for the first time revealed a white dwarf producing a micronova. TESS is set up to search for very little fluctuations in a star’s luminosity caused by an exoplanet transiting in front of the star.
Instead of a weak flash, the scientists spotted a white dwarf star’s quick burst of light in the TESS data, which led them to the micronova. The hunt for comparable occurrences in other white dwarfs has been sparked by this. They discovered three explosions in total, with the third leading to the identification of a previously unidentified white dwarf through further studies.
The group then came up with a scenario that could account for the findings. They discovered that micronovae is the most likely cause.
A white dwarf can absorb matter from its companion when it is in the binary form and has a strong magnetic field. This material is drawn by the white dwarf’s magnetic field to its poles, where it builds up and eventually explodes.
For the first time, astronomer Paul Groot of Radboud University in the Netherlands observed that hydrogen fusion might possibly take place locally.
“Some white dwarfs have the capacity to store hydrogen fuel at the base of their magnetic poles, limiting fusion to these magnetic poles. This results in the detonation of tiny thermonuclear bombs, known as micronovas, which have an explosion one millionth the size of the supernova we already know about “.
A long-standing mystery might be resolved by the finding. Over the past 40 years, comparable flashes have been recorded from one of the white dwarfs in the TV Columbae binary system. The result indicates that outbursts may occur frequently, but additional observations are required to fully comprehend them.
How do you feel about these new findings by astronomers? From these new discoveries, we know that there are many things in the universe that we have not found or discovered yet. Hopefully these outer space explosions will not affect our earth.