Hubble works to understand how stars are born

Hubble may be on the verge of retirement with the upcoming arrival of the James Webb Space Telescope, but it is still capable of finding extraordinary phenomena in some corner of the sky.

Since the dawn of time, the sky has been filled with stars. As immobile, we can wrongly think that they have always been there, and yet stars are more or less young. Our ancestors the Greeks had thus spotted constellations in the middle of their black sky, with more or less brilliant stars.

If the sky has not really changed since, at least the changes are not visible to the naked eye, it would be possible today for very powerful telescopes like Hubble is, to create new constellations on the same model than that of the Greeks. Indeed, some stars are born when others die, and their cycle of evolution is fairly well known today.

In fact, the death of a star is scientifically much better documented than its birth. It is in fact easier to follow the evolution of something that was and is no more than to observe “nothing” while waiting for it to become something. But to be more exact, this “nothing” is not really composed of interstellar void.

Star formation, a poorly understood phenomenon

Indeed we know today that stars are formed by a phenomenon called the gravitational collapse of matter in the cold stellar gas clouds of the galaxy. The matter will accumulate in one place even before the various thermonuclear reactions take place. As the pressure increases with the material, the temperature will also rise, causing a release of light in the heart of the cloud.

But since the start of the study of these protostars, we notice that they have always emitted jets of matter, often in a bipolar way. One of these protoplanet jets has just been spotted by the experienced Hubble telescope. Present in the sky for more than 30 years, this last one is not with its first discovered protoplanet, but this new find has a particular flavor.

Indeed, it has been thought for a long time that the jets of matter at the two poles of the stars make it possible to reduce the speed of rotation of the star on itself. One way to explain why in our system the Sun turns so slowly on it (because yes it is not still). If Hubble did not discover anything that we did not already know, the telescope allowed us to contemplate the sky once again, in its most beautiful aspects.

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