Astronomer Denilso Camargo, from the Brazilian Ministry of Defense's Military College in Porto Alegre, has made a remarkable discovery. After combing through data gathered by NASA's Wide-field Infrared Survey Explorer (WISE) satellite and analyzing telescope images of the Milky Way, Camargo has managed to find not one, but five rare globular clusters tucked away in the center of our galaxy.
This type of star clusters, recognized by their spherical shape and named after the Latin word for sphere, "regulus," are incredibly old. Crammed with hundreds of thousands of stars, globular clusters are ancient and very dense star bundles that date back almost to the beginning of the universe.
'Living Fossils' From Our Galaxy's Early Days
In fact, according to the Brazilian media outlet Revista Galileu, the five globular clusters recently discovered by Camargo are between 12.5 and 13.5 billion-years-old and have formed just a few hundred million years after the Big Bang, which occurred 13.8 billion years ago.
"Globular clusters were the first stellar systems formed in the early universe and are often considered as living fossils of the galaxy's formation," explained Camargo.
The newly discovered globular clusters are now known as Camargo 1102, 1103, 1104, 1105, and 1106, and have been spotted by the astronomer in the central region of the Milky Way, also called the galactic bulge.In a new study published this week in The Astrophysical Journal Letters, the Brazilian astronomer reveals that the five ancient star clusters reside "less than four kiloparsecs [around 12,000 light-years] from the galactic center."
"Camargo 1102 seems to be located over the galactic bar on the far side of the Milky Way and at a vertical distance lower than one kiloparsec [3.26 light-years]. The other four clusters lie even closer to the Milky Way mid-plane," the study author wrote in his paper.
Less Than 200 Globular Clusters Discovered So Far In The Milky Way
As the Inquisitr previously reported, globular star clusters are quite rare in our galaxy. While giant elliptical galaxies boast several thousand globular clusters, the Milky Way has far less.
As Camargo told Forbes, there are less than 200 globular clusters orbiting the Milky Way's galactic core. This makes Camargo's recent discovery that much more significant.The astronomer points out that these ancient star clumps are "a powerful tool" in furthering our understanding of how our galaxy formed and evolved during its early stages.
"The galactic bulge formation and evolution is one of the most important unsolved problems in the present epoch and, thus, remains a subject of intense debate," said Camargo.
Clues On Galaxy Formation And Evolution
Another thing we can learn by studying the globular clusters in our galaxy are details on the Milky Way's "bulge structure and kinematics," since these ancient star clusters "provide a means for tracing the galaxy's properties at the present time," stated the astronomer.
For instance, after going through data from the 2MASS ground-based infrared survey and the European Space Agency's Gaia satellite — particularly the second slew of Gaia data, which was released in April and included a vast stellar map of nearly 1.7 billion stars, the Inquisitr reported at the time — Camargo found out some of the properties of the five globular clusters and was able to ascertain that they are very poor in metal.
This makes sense considering that, for the first few millions of years, the universe was abundant in hydrogen and helium, while other elements were synthesized much later, notes Revista Galileu.
As Camargo explains in his study, the newfound globular clusters "have the potential of providing important clues on the early inner galaxy formation and its subsequent evolution."
Other Stellar Discoveries
To top it all off, the Brazilian astronomer has also contributed to the finding of 1,101 open star clusters in the Milky Way. Two of these star clusters, Camargo 438 and Camargo 439, made headlines in 2015 when a study published in Monthly Notices of the Royal Astronomical Society announced that embedded clusters had been found at the edge of our galaxy.As NASA reported at the time, the two globular clusters, described by Camargo as "truly exotic," were uncovered in a giant molecular cloud out in the middle of nowhere, in a region of the Milky Way previously believed to be more or less empty.
This was the first time ever that astronomers found young stars forming so far away from our galaxy's usual stellar nurseries — an experience that Camargo's team repeated in 2016, with the finding of seven other embedded clusters (Camargo 932, 934, 939, 1074, 1099, 1100, and 1101) at a vast distance from the galactic disk, revealed a study featured in Astronomy & Astrophysics.
"This work points to a new paradigm in the star and star cluster formation, in the sense that the formation of such objects occurs in the halo and it seems to be frequent," Camargo told Phys.org at the time.