A team of astronomers from Haverford College (USA) has discovered the two furthest stars in our galaxy , on the outskirts of the Milky Way; what is known as “galactic halo”. The finding has been published in the Astrophysical Journal Letters .
The new discovered stars are two red giant stars , named ULAS J0744 +25 and ULAS J0015 +01 and are very distant: 775.00 and 900,000 light years away, respectively. Red giant stars are relatively rare when compared to the red dwarfs we know, but their difference is remarkable since they shine almost 10,000 times more than the others, so they are visible at enormous distances.
Their identification has been possible thanks to the combination of filters highlighting different parts of the optical and near-infrared light from both stars. Once done, the astronomers obtained spectroscopic confirmation of the identity of the two red giants using the 6.5-meter telescope of the MMT Observatory located on Mount Hopkins in Arizona (USA).
To date, astronomers have only discovered seven stars at this location; This is because the distances are so huge and the stars are so scattered that identifying them is not an easy task. However, knowledge of these stars would be very valuable for understanding the origin and evolution of our galaxy.
“The distances to these two stars are almost too great to understand. To put it in perspective, when the light from ULAS J0015 +01 left the star, our first human ancestors were starting to make fire here on Earth, ”says John Bochanski, leader of the study. Not surprisingly, both stars are five times more distant than the Large Magellanic Cloud.
