nuclear star cluster Archives

April 5, 2024April 5, 2024 by Evan Gough

The Stellar Demolition Derby in the Centre of the Galaxy

This illustration shows stars orbiting close to the Milky Way's central supermassive black hole. The black hole accelerates stars nearby and sends them crashing into one another. Credit: ESO/L. Calçada/Spaceengine.org

The region near the Milky Way’s centre is dominated by the supermassive black hole that resides there. Sagittarius A*’s overwhelming gravity creates a chaotic region where tightly packed, high-speed stars crash into one another like cars in a demolition derby.

These collisions and glancing blows change the stars forever. Some become strange, stripped-down, low-mass stars, while others gain new life.

October 25, 2023October 25, 2023 by Evan Gough

Astronomers Want JWST to Study the Milky Way Core for Hundreds of Hours

This overview of the Milky Way's Galactic Center (GC) shows the region of the proposed JWST survey. Image Credit: NASA/JPL-Caltech/S. Stolovy (Spitzer Science Center/Caltech)

To understand the Universe, we need to understand the extreme processes that shape it and drive its evolution. Things like supermassive black holes (SMBHs,) supernovae, massive reservoirs of dense gas, and crowds of stars both on and off the main sequence. Fortunately there’s a place where these objects dwell in close proximity to one another: the Milky Way’s Galactic Center (GC.)

October 7, 2020October 7, 2020 by Evan Gough

7% of the Stars in the Milky Way’s Center Came From a Single Globular Cluster That Got Too Close and Was Broken Up

Central region of the Milky Way in infrared light. With this image, NASA's Spitzer Space Telescope has photographed the inner 890 x 640 light years of the Milky Way. The nuclear star cluster is located in a small area near the central massive black hole. The extended structures in the image are mostly clouds of gas and dust from the spiral arms of the Milky Way, which lie in the line of sight between Earth and the Galactic Centre. Image Credit: NASA/JPL-Caltech/S. Stolovy (Spitzer Science Center/Caltech)

The heart of the Milky Way can be a mysterious place. A gigantic black hole resides there, and it’s surrounded by a retinue of stars that astronomers call a Nuclear Star Cluster (NSC). The NSC is one of the densest populations of stars in the Universe. There are about 20 million stars in the innermost 26 light years of the galaxy.

New research shows that about 7% of the stars in the NSC came from a single source: a globular cluster of stars that fell into the Milky Way between 3 and 5 billion years ago.