The Alma Telescope Tracked The "Germs" Of Luminaries Inside The Triple Star System
European astronomers first tracked the first stages of the formation of a triple star system in the constellation Ophiuchus and saw the "embryos" of its luminaries. They published the results of their work in the electronic scientific library arXiv.
"Our observations confirmed that there are three forming stars inside this object, and also for the first time allowed us to see small disks of gas and dust that surrounded each 'germ.' Both of these structures, in turn, are embedded in an even more complex cloud of dust and gas," said Maria Maureira, head of the study, an astrophysicist from the Max Planck society's Institute for extraterrestrial physics.
Astronomers believe that most of the stars in the Milky Way are located inside double or triple star systems. In particular, they include the three nearest stars to us-Proxima Centauri, Rigel Centauri, and Toliman, United in the triple system of Alpha Centauri.
Until recently, scientists believed that stars are always formed separately from each other and only then, due to gravitational interactions between newborn stars, are combined in pairs or threes. This happens inside the so-called "star manger" - gas and dust clouds, where new stars are formed.
However, when astronomers moved away from the theory and began to monitor this process with telescopes, these ideas proved to be erroneous. Observations have shown that almost all binary stars form together, inside the same clumps of matter.
Such discoveries have given rise to a lot of debate about whether such conditions can produce not only stars, but also planets, and whether such objects can in principle be habitable. Given the high prevalence of double and triple stars, the answer to this question is very important to assess the probability of extraterrestrial life.
Maureira and her colleagues have taken a big step towards getting answers to all these questions. In the course of their new work, they observed the newborn star system IRAS 16293-2422, which is located in the constellation Ophiuchus at a distance of 460 light-years from Earth. It was discovered at the end of the last century and since then scientists have considered this system one of the youngest "embryos" of stars that are close to the Solar system.
Previously, astronomers could not look "inside" this star system and track how the gas-dust disks that "feed" newborn stars and probably participate in the formation of planets are formed. The fact is that it was "blocked" by a large amount of gas and dust. Until recently, scientists only knew that there were two newborn stars inside IRAS 16293-2422, as well as a protoplanetary disk surrounding them.
The Alma microwave telescope, which was completed in 2013, helped astronomers learn more. It combines the power of 66 smaller telescopes that can track the movement of even the coldest molecules of various gases.
Using ALMA, Maureira and her team tracked the movement of carbon monoxide molecules inside IRAS 16293-2422. They contained both light carbon-12 and its radioactive heavy isotopes-carbon-17 and carbon-18. thanks to this, scientists investigated where and at what speed the gas moves inside the invisible part of the "germs" of stars, and made an unexpected discovery.
It turned out that one of these protostars, object A, as it was previously called by astronomers, actually consists of two separate "embryos" of luminaries (they were temporarily named A1 and A2). The first is almost as massive as the Sun, and the second is about 1.4 times heavier than our star. They were located about the same distance from each other as Pluto is from the Sun.
In addition to protostars, astronomers examined the surrounding gas-dust disks, and also found a similar structure in the second previously known star, the b star. Also, images from ALMA indicated the existence of gas flows that simultaneously connect the stars into a single whole and serve as a source of new matter from a larger gas-dust cloud that surrounds the entire system inside IRAS 16293-2422.
Further study of these objects, scientists hope, will help to understand why these disks are tilted to each other at very different angles and learn the full history of the formation of this young star system. In the next few million years, scientists expect it to turn into an almost complete analog of Alpha Centauri, which makes it particularly interesting to observe.