NEW DELHI (TIP): Astronomers have discovered two Red Giant stars at the very outskirts of the Milky Way, in a lonely and unexplored region of space. One of them is 890,000 light years from Earth in the constellation Pisces while the other is about 780,000 light-years distant in the constellation Gemini and more than a million lightyears from the other star.

At these distances both the stars easily become the most distant stars found in our Milky Way. The previous record holder was only 500,000 light years from Earth “They’re the most distant stars that we’ve ever seen in our Milky Way,” says John Bochanski of Haverford College, the astronomer who found them, quoted by Scientific American magazine.

The finding appears in the July 20 issue of The Astrophysical Journal Letters. Bochanski and his team drawn from Harvard, Boston University and Michigan State University in the US and the Kapteyn Astronomical Institute in the Netherlands, started off with seven million stars and using various kinds of measuring instruments whittled it down to 404 M-type stars.

After getting spectra from a group of this stars theyfound that most were red dwarfs but five of them were red giants. Of these, only two were dim, indicating that they were very far from Earth. These lonely stars present a riddle for astronomers. There brightness suggests that they are M-type stars containing metals.

But such stars have never been found at such great distances. Usually, stars in the Milky Way’s halo, that is, the envelope of ancient stars that surround the galaxy’s main disk, have much less heavier elements and cannot become an M-type red giant. Scientists are speculating about how these red giants came to be patrolling the perimeter of The Milky way in their lonely orbits at such a great distance from the galactic center. One theory is that they drifted in from a neighboring galaxy.

There are two dozen galaxies that orbit the Milky Way and two of the closest ones, called the Large and Small Magellanic Clouds, have many stars like these M-type red giants. But if that happened then such a galaxy should be bright enough to be visible. It is possible that the original home galaxy of these two is so diffuse that we can’t see it or it may even have disintegrated.