Like the sun, there was a time when a middle-aged adult star who was over 4.6 billion years old was a baby. Scientists do not have pictures of when the Sun was a baby star, but they have observed several baby stars of similar mass in our galaxy and have gathered a lot of information regarding how they were born and grew up.
However, it is difficult to know whether this process is similarly occurring in other galaxies. This is because it is not easy to observe a dark baby star that has just been born in distant outer galaxies.
Recently, a research team led by Professor Kazuki Tokuda of Kyushu University in Japan used the Atacama Large Millimeter/submillimeter Array (ALMA), a powerful radio telescope installed in the alpine region of Chile, to observe baby stars in the Small Magellanic Cloud, a satellite galaxy of our Milky Way. did.
Usually stars are formed by the aggregation of gas and dust in gas nebulae. Therefore, most of the baby stars are surrounded by thick gas and dust, making it difficult to observe from Earth. Because ALMA uses radio waves with longer wavelengths than visible light, it is advantageous for observing through such thick gases. However, observing baby stars in neighboring galaxies was not an easy task.
The team stumbled upon Y246, a baby star spewing very powerful gas in the Small Magellanic Cloud. Y246 started a nuclear fusion reaction when it reached a critical mass by collecting gas from its surroundings as a large-mass baby star.
A baby star that has absorbed more material emits powerful energy and gas in both directions. It is no different than the cry of a baby star.
By detecting the wavelength of the carbon monoxide molecule, the research team found that Y246 was spewing a powerful gas at speeds exceeding 54,000 km/h. (See photo) The pattern was not significantly different from the stars in our galaxy.
In fact, the Small Magellanic Cloud is a satellite galaxy of our own Milky Way, but it is not a galaxy with similar properties to our own. Scientists believe that the composition of the Small Magellanic Cloud is so primitive that it resembles galaxies 10 billion years ago.
However, this study shows that the process of star formation is not very different from that of our galaxy. Therefore, it is highly probable that the birth and growth of stars occurred in a similar way without major changes from the beginning of the universe to the present. There are many stars in the universe, and they all have their own stories, but the process of birth was similar.
Gordon Jung Science Columnist [email protected]
