As you know, in the solar system there are 8planets, the largest of which is Jupiter, could easily become a star if its mass increased by several percent. Despite the fact that the luminosity of such a star would leave much to be desired, two luminaries could coexist in our solar system at once. It is worth noting that such “non-stars” make up a large part of our Universe, greatly blurring the already fuzzy line between small stars with low temperature and planets.
How to turn a planet into a star?
According to an article published in the journalScience, the recent discovery of a massive planet that revolves around the small star GJ3512 casts doubt on our understanding of how planets form. A dwarf star, whose luminosity is less than 0.2% of the solar, is located at a distance of 30 light years. Such cold and extremely dim objects are actually the most common stars in the galaxy, although they are also the most difficult to distinguish stars in the night sky. The planets located next to such stars are very difficult to detect even by the “Doppler shift” method, which is widely used in astronomy. The application of this method is based on the detection of a shift in the wavelength of starlight by a tiny amount, when an invisible planet rotates, pulling the star back and forth.
A planet called GJ3512b is prettya large gas giant orbiting in a 204-day elliptical orbit around its star. The mass of this distant world is at least half the mass of Jupiter, and its diameter is probably about 70% of the diameter of the star around which it rotates. Thus, GJ3512b is one of the largest known planets that rotate around a small star in a wide orbit, which creates a problem for understanding how it formed.
It is believed that the solar system originates fromthe so-called "protoplanetary disk" - a cloud consisting of dense gas and dust from a supernova explosion. At the same time, gas giants were the first to form, whose rocky ice cores were created by the accumulation of smaller bodies in the outer regions of the protoplanetary disk. When the nuclei reached about ten earth masses, they were able to surround themselves with a hydrogen-gel shell, which formed the atmosphere of modern giant planets such as Jupiter and Saturn.
However, found in large numbers“Hot Jupiters”, which are located in close orbits to their parent stars, show that the method of their formation is no different from the above, which baffles modern researchers, because the protoplanetary disk of the red dwarf hardly had enough material to form giant planets.
A little more astronomy: Astronomers continue to wonder about the habitability of the planetary system TRAPPIST-1
An alternative scenario for the origin of the planets,probably happened in the case of GJ3512b. In this case, the planet could be formed as a result of direct fragmentation of the protoplanetary disk, in which part of it collapses and condenses even without the need to accumulate by connecting smaller rocks. In other words, the planet GJ3512b could have formed in the same way as the stars themselves.
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The discovery of this unique system createsa lot of questions regarding the difference between brown dwarf stars and planets, because it turns out that stars and planets differ only in mass. If so, can the planet turn into a star?
Imagine maybe. In the event that in the protoplanetary cloud surrounding the newborn star there is a sufficient amount of building material, then the planet can really turn into a star, the size of the Sun, or even a blue giant, the size of Sirius. There is a theory that Jupiter can be turned into a star by adding to it some additional mass, which will provoke the beginning of thermonuclear fusion in the bowels of the planet. However, why do we need to do this and whether it is necessary at all - time will tell.