In an effort to test predictions for the formation of the Milky Way, Sky and Telescope tells us that Dr. John Bochanski and his team of astronomers have discovered the two most distant stars ever recorded in the Milky Way galaxy. The discovery by Dr. Bochanski and his team is important because data gathered about the two most distant stars ever found will help us understand more about the formation and evolution of our galaxy.
Dr. Bochanski and his team of scientists began their search for the Milky Way’s most distant stars by targeting the outer halo of our galaxy.
Sky and Telescope describes the Milky Way’s outer halo as “a sparse shroud of stars that surrounds the disk of our galaxy.”
“The discovery of the Milky Way’s known two most distant stars is no small feat of accomplishment because the Milky Way’s outer halo stretches a massive 500,000 light years out from the Milky Way’s center. After two years of searching, an enormously vast swath of the Milky Way’s outer halo, Dr. Bochanski and his team can claim victory.”
Sci-News informs us that Dr. Bochanski and his team made their discovery by using the Red Channel spectrograph at the MMT Observatory on Mount Hopkins in Arizona. The Milky Way’s two most distant stars known to us are named ULAS J001535.72+015549.6 and ULAS J074417.48+253233.0, and are located at distances of 775,000 and 900,000 light years from Earth, respectively.
The fact that Dr. Bochanski and his team were able to locate any stars at such vast distances across the Milky Way is astounding given that, prior to this discovery, there were only seven known stars located beyond 400,000 light years from Earth.
Sci-News illustrates just how far these distances are from Earth by quoting an example given by Dr. Bochanski. Dr. Bochanski stated, “The distances to these two stars are almost too large to comprehend. To put it in perspective, when the light from ULAS J001535.72+015549.6 left the star, our early human ancestors were just starting to make fires here on Earth.”
The two distant stars discovered by Dr. Bochanski and his team bear significance beyond their distances from Earth. Dr. Beth Willman, the co-author of Dr. Bochanski’s paper regarding the discovery of the two distant stars, explains to us just how significant this study could be in the world of astronomy, and to potentially disproving things we think we know about how the Milky Way was formed.
Dr. Willman, in her example illustrating the sparseness of the Milky Way’s outer halo, states:
“Some astronomers think that the halo is like a cloud of galactic crumbs, the result of the Milky Way’s merger with many smaller galaxies over our Galaxy’s lifetime. Theory predicts the presence of such an extended stellar halo, formed by the destroyed remains of small dwarf galaxies that merged over the cosmic ages to form the Milky Way itself. The properties of cool red giants in the halo thus preserve the formation history of our Milky Way. These stars are truly ghosts of galaxies past.”
With the importance of Dr. Bochanski’s discovery noted due to the historical preservation contained within the Milky Way’s two most distant known stars, Dr. Bochanski makes it clear to us that the findings from his two-year study have the potential to change existing astronomical models.
Dr. Bochanski said:
“Most models don’t predict many stars at these distances. If more distant red giants are discovered, the models may need to be revised.”
This summer has been an eventful time period regarding new discoveries made about our home galaxy, the Milky Way. The Inquisitr goes on to cover additional Milky Way related phenomena in more detail.