b Centauri b: The planet which shouldn't exist.
- Dev
- Dec 14, 2021
- 3 min read
Welcome to Astronosmia! We have discovered over 4,000 exoplanets orbiting different star systems across the Milky Way galaxy. But, one of the recent discoveries made by the Very Large Telescope at the European Southern Observatory in Chile has left astronomers baffled.
The newly discovered exoplanet b Centauri b is a relatively interesting planet. The planet lies 325 light-years away from Earth in what is being called one of the most massive star systems. The discovery also states that the planet lies in one of the heaviest star systems. The combined weight of the two stars of b Centauri b is said to be 6-10 times the weight of our sun! The planet b Centauri b is said to be a mass of 11 Jupiters and it orbits its star at a distance of 52 billion miles! In order to visualise this, you can compare b Centauri b's orbital distance with Pluto's orbital distance which is roughly 3 billion miles. Now you can think of the enormous orbital distance of this planet with respect to its star.
"Finding a planet around b Centauri was very exciting, since it completely changes the picture about massive stars as planet hosts," study lead author Markus Janson, an astronomer at Stockholm University in Sweden, said in a statement.
THE STAR SYSTEM
The planet b Centauri b lies in a two-star system or a binary star system. The two stars are relatively young than our Sun. The two stars of this system are 15 million years old whereas our Sun is 4.5 billion years old. As per the discovery, the two stars are B-type stars. There are namely 7 types of stars - O, B, A, F, G, K, M with O being the most massive and M being the least massive. B-type stars are less massive as compared to O-type stars but are considered dangerous due to the extreme temperatures.
The main star of this system, b Centauri A is a B-type star that has a temperature of around 18,000° Celcius or (32,000° Fahrenheit) which is three times hotter than a G-type star. Our Sun is a G-type star having temperatures of around 5000° Celcius. Due to the harsh environments of these stars, it is believed that B-type or similar massive stars have difficulty in forming planets which makes this discovery even more intriguing.
WHY IS THIS DISCOVERY IMPORTANT?
Due to the fact that planet formation around these stars was considered impossible, b Centauri b has changed this perspective of astronomers. The discovery of this planet means there could be more planets like these. Now, due to the massive orbital distance of this planet from its parent stars, the planet may have escaped the harsh radiation of its parent stars. The main question which arises now is how this planet may have formed in such an environment?
There are namely two ways of planet formation. One way is the core accretion. This method involves the collision and gradual aggregation of solid particles, dust which ultimately leads to planet formation. But the current position of this planet makes it less viable for formation via core accretion. Astronomers suggest that the planet may have formed via core accretion and then due to interactions of gravity, it may have re-located to its current position.
Another way of formation of this massive alien exoplanet could be gravitational instability. Gravitational instability suggests that a part of a protoplanetary disk collapses under the pull of its own gravity which gives rise to a secondary object orbiting the star. Kaitlin Kratter of the University of Arizona's Steward Observatory however suggested that the formation of this planet via gravitational instability is less likely than core accretion.
CONCLUSION
The discovery of this planet is an intriguing one as it has posed new challenges and asks for newer perspectives. Astronomers suggest that there could be more planets of this kind. The discovery of such planets around such massive stars will further help scientists to unravel the secrets of this universe.
**What do you make of this discovery? Did you find it interesting? Comment your views in the comments section below!**
**Also, do read my other posts if you are an astronomy enthusiast!**
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