“The discovery of this exceptional globular cluster remnant will help refine models of the formation of the first stellar structures of the Universe,” astronomer Nicolas Martin told The Daily Galaxy about the discovery of a stellar structure known as C-19 uniquely comprising stars with extremely low metallicity. Recent studies suggest that planetary systems made up of terrestrial-type planets in compact, tightly-spaced orbits are most likely to form around lower-metallicity stars. Small planetary systems orbiting low-metallicity stars have been around a lot longer, and may be the earliest type of planetary system, making them an ideal place to search for life.
The Milky Way is a dynamic museum of ancient merging relics, river-like streams of stars stripped from dwarf satellite galaxies that flow through the galaxy revealing its history and structure that allow astronomers to better understand how galaxies in the universe have formed and evolved.
Hubble astronomers found something extraordinary at the heart of nearby globular cluster NGC 6397 –a concentration of smaller black holes lurking there instead of one monster, supermassive black hole. Ancient stellar jewelry boxes, globular star clusters are densely packed objects, glittering with the light of a million stars in a ball only about 100 light-years across dating back almost to the birth of the Milky Way.
Most stars in the universe –including our life-giving Population 1, main-sequence Sun, one of more than 100 billion stars in the Milky Way, that formed approximately 4.6 billion years ago–are formed a massive star clusters created from the violent gravitational collapse of matter within a region of a large molecular cloud. These clusters are the building blocks of galaxies, but their actual formation from these dense clouds is a mystery.
An enormous “something” more massive than a star, appears to have torn a hole in part of the Milky Way’s halo. The “dark substructure” was found in data from Gaia spacecraft observations—a mission producing the most detailed 3D map of our galaxy—with Harvard’s Ana Bonaca noticing a perturbation in a tidal stream. Bonaca is a leading authority on how the tidal field of the Milky Way galaxy disrupts globular clusters, and what the resulting debris can tell us about the underlying distribution of dark matter. (more…)