A large family of newborn stars seems to be now on separate roads: more than 1,000 stars are hurriedly flowing their nest in record time, which leads to a kind of mystery about the cause of this stellar break.
In general, a few hundred million years are needed for a cluster either stars They are born together to break, gradually separated by gravitational tide forces from each other and other objects that pass. For example, the famous Pleiades Star Cluster (Messier 45), which is a group of young stars visible to the naked eye in the Constellation either Taurus, the bullHe is 100 million years old, while the hive cluster (Messier 44) in Cancer, the crabAround 600 million years (and a little more scattered than Pleiades).
However, a young open stars, just 20 million years, seems to be playing for a different set of rules. Use of data from European space agencies Gaia missionThat measured the position, speed, distance and spectra of approximately two billion stars, astronomers led by Dylan Huson of the Western Washington University discovered that the thousand stars of this new cluster are also moving to remain in Therm.
The cluster is about 650 light years in Ophiuchus, the snake carrierand has been nicknamed “Ophion” in honor of its resident constellation.
“Ophion is full of stars that rush through the Galaxy In a totally unpleasant, unpleasant way, which is far from what we would expect for such a big family, “Huson said in a statement. “In addition, this will happen in a fraction of the time that used Usumby so that such a large family is dispensed. It is like no other star family that we have seen before.”
The range of speeds in a stellar cluster is known as its speed dispersion. Because the giant molecular clouds that give to the stars are cold, have low energy and, therefore, low speed dispersions of only a few kilometers per second, which pass to their incipient stars.
This means that the stars of a cluster should move more or less the same low speed, which allows their mutual severity to keep them for longer. The speed dispersion in Ophion, measured by Gaia, is much larger than normal, 20 kilometers (12.4 miles) per second. In other words, the difference between faster and most slower stars in Ophion is 20 kilometers per second.
With such high speed dispersion, Ophion will fly quickly. The only reason we see these stars together is because they are very young and that they house was the opportunity to separate.
“We do not know exactly what happened to this star family to advance, since we find nothing that reigns before,” said Marina Kounkel, from the University of Northern Florida, which was part of the discovery team. “It’s a mystery.”
Ophion’s existence was not immediately obvious. The Huson and Kounkel team was testing a new model, called Gaia Net, which can simultaneously analyze the spectra of millions of stars, when the cluster left the data.
“This is the first time it is possible to use a model like this for young stars, due to the immense volume and high quality of the spectroscopic observations necessary for it to work,” said Johannes Sahlmann, scientist of the GAIA project in the European Space Agency. “It is still quite new to be reliably measure the parameters of many young stars at the same time. This type of bulk observation is one of Gaia’s truly unprecedented achievements.”
So what has led Ophion’s stars to go out with their own trajectories so early in his life? While examining Gaia’s data, Huson’s team noticed several large gaps, areas where Supernova Shock waves have flown interstellar gas. Astronomers call these “superbubbles” empty, and it is possible that much of the remote gas in Ophion after the formation of their stars was also impressed by the stellar explosion waves. Losing so much mass under the cost of this whole gas had a feedback effect, losing control of the cluster over its stars. The effects of gravitational tides of the mass of the neighboring stars -forming regions could also have given the Ophion stars an additional impulse.
“Emotionally, it changes how we think about stars slimming and how to find them. The previous methods identified families grouping the stars in a similar way, but Ophion would have slipped through this network,” Kounkel said. “Without the huge high quality data sets of Gaia, and the new models that we can now use to dig in these, we can have a bone that is missing a great piece of the star puzzle.”
Therefore, there may be other young families or stars that run separately. Our vision of Ophion is like a photograph of a young adult just before leaving the university. They are on their way, but the port has yet left the nest. Where these stars will end is a assumption of anyone, but they are destined to wander only by the space lanes.
The Huson team presents the Gaia network model in a New studywhich was published on April 25 in Astrophysical magazine.
