There is a galaxy located in the space close to our Milky Way which is pretty weird. Is called Segue 1, and is very small and weak. Is in constant rotation in our galaxy, and until now no one knows where it came from.
However, now a team of astronomers have managed to measure with precision its movement for the first time.
Segue 1 is a small class of galaxy, is very compact and occupies the space somewhere between a globular cluster and a dwarf galaxy.
This type of galaxy is known as “ultra-faint dwarf spheroidal galaxies” (or “galaxy dwarf spheroidal“, in Spanish), and Segue 1 has been the first discovered in the data obtained by the Sloan Digital Sky Survey in 2006. In the year 2007 was published a scientific document that describes this class little known galaxy.
Segue 1 is a galaxy full of star old or very old and dating back to the Early Universe. It is known that it has little metal content, which is related to an object that is very old. This can be explained because the metal does not spread through the universe until some stars became supernovae, generating the heavy elements.
Another of its characteristics is that it has a lightness or brightness of approximately 300 suns. This is much weaker than a cluster globular typical.
However, astronomers are not yet sure that it is not a globular cluster; the difference seems to be in the history of formation of both objects. However, this new research could end the question about Segue 1.
But the team not only sought to find out if Segue 1 is a galaxy or a globular cluster, the researchers also wanted to determine where it comes from and how it ended up orbiting the Milky Way at a distance of 75,000 light years.
Determining the origin of the galaxy
To perform the present study, the scientists used data from the Sloan Digital Sky Survey and the Large Binocular Camera, a 10-year period that allowed them to calculate the movement of Segue 1. They found that Segue 1, orbiting the Milky Way once every 600 million years ago.
This distance is very large for that Segue 1 is a star cluster, because that could have been annihilated by the gravity of the Milky Way.
Therefore, it is more likely that Segue 1 is a galaxy, which supports the previous findings that claim that, even though the galaxy has low metallicity, it has a significant amount of iron, something that can’t be found in globular clusters.
To the question of how he got there, there is still no certainty. However, the researchers found two most plausible scenarios.
What is more likely is that Segue 1 is a satellite orbiting around a galaxy. Scientists believe that Segue 1 collided with the Milky Way over 12 billion years, as a result being a small galaxy, Segue 1, rotating by itself.
In the past, the Milky Way has merged with other galaxies, and astronomers can even see the ripples left by those collisions. However, the orbit of Segue 1 is not consistent with any of the collisions known, but it is possible that some astronomer has not discovered yet.
Another option, and that the team believes that it is more possible, is that Segue 1 was wandering around the space, until a day ago 8 billion years ago, was captured by the Milky Way.
It will take more observations and analysis in the future to determine the best way the origin of Segue 1, but for now it seems that we will have a small and very strange galaxy neighbor.
The full article has been published in The Astrophysical Journal.
A publication of CodigoOculto.com – Author: Fernando T. – All rights reserved.