The smallest known star in our Milky Way galaxy to support hydrogen fusion in its core is the EBLM J0555-57Ab. It is surprising to note that this star is smaller in diameter than Jupiter. It begs to ask the question, “Can Jupiter, being a gas giant, become a star?”
To better understand, let’s compare Jupiter with the biggest object in our solar system, the Sun. With a density of 1.33 gms per cubic centimeter and mass composition of 71% hydrogen and 27% helium, Jupiter is compositionally similar to the Sun, which has a density of 1.41 gms per cubic centimeter and 73% hydrogen and 24% helium mass composition.
With so many similarities, why didn’t the fusion reaction kick start in Jupiter? Simple answer, Jupiter doesn’t have enough mass to fuse hydrogen into helium. The star EBLM J0555-57Ab is about 85 times heavier than Jupiter, and this mass is considered critical – if anything lower, it will not support fusion. For this reason, Jupiter is referred to as a failed star.
To further understand the reasons, let’s look at the process of stars and planets’ formation in the Universe. Stars form by accumulating gas and dust in the interstellar cloud that collapses under its own gravity. As it spins and accretes, the gravity increases, compressing the material to a point where the core ignites, starting a fusion reaction.
On the other hand, planets are formed by accreting materials from what is left of the star formation. According to astronomers, Jupiter was formed by accreting small chunks of icy rocks and dust that stick together due to static electricity. Once it accumulated enough mass, it started accumulating more and more gases that were available to it. But it fell short of the mass required for a fusion.
Since Jupiter formed from the same molecular cloud from which the Sun formed, it is similar in density and composition to the Sun. But it was never was at a mass level or even close to becoming a star. Data from NASA’s Juno probe suggests that Jupiter once had a solid core, consistent with the core accretion formation method. For these reasons, Jupiter is not a failed star.
So what are failed stars?
A brown dwarf is a true failed star. They have masses starting at around 13 times that of Jupiter and can support the fusion of heavy hydrogen -deuterium. Deuterium fusion is an intermediate step in star formation as it continues to accrete mass towards hydrogen fusion; however, these stars never achieve that critical mass.
Understanding the formation of cosmic objects is critical to understand the formation of life on Earth.
Do you want to publish on Apple News, Google News, and more? Join our writing community, improve your writing skills, and be read by hundreds of thousands around the world!