For the first time, a remnant of Milky Way's ancient heart was discovered at the center of the galaxy.
The European Space Observatory (ESO) and its VISTA telescope discovered remains of an ancient star type called RR Lyrae. RR Lyrae is usually seen inside ancient stellar populations that are 10 billion years old. This discovery suggests that the heart of Milky Way is a result of the combining and merging of star clusters of the entire galaxy.
A research team led by Dante Minniti of the (Universidad Andrés Bello, Santiago, Chile together with Rodrigo Contreras Ramos of the Instituto Milenio de Astrofísica, Santiago also in Chile used the data gathered by the VISTA Infrared telescope in studying Milky Way's ancient heart. Observations used were part of the Variables in the Via Lactea (VVV), an ESO public survey that is looking through the center of the Milky Way galaxy.
To get a clearer view of the galaxy's heart, the researchers used infrared lights that are only slightly affected by the cosmic dust as compared to visible light. These gave the researchers excellent conditions at ESO's Paranal Observatory where they found dozens of RR Lyrae in the heart of Milky Way that were discovered and identified for the first time, according to a press release by the observatory.
Most galaxies have populated centers just like Milky Way. The discovery of LL Lyrae in the center of Milky can help astronomers compare and understand the origins of nuclear bulges.
The RR Lyrae varies in terms of brightness that makes them "variable stars." To calculate the distance of RR Lyrae, astronomers observe the length of each cycle consists of brightening and dimming of the star.
It seems easy in theory, but the existence of brighter and younger stars and bodies outshine RR Lyrae making it more difficult to study and observe and detect. This is probably one of the reasons why the remnants of Milky Way's heart were only discovered today, for the first time.
Locating these type of stars in a crowded region in the center of the Milky Way galaxy is not an easy task. They are also considered as the oldest stars in the galaxy.