A fossil from the Milky Way’s youth, quietly glowing in the southern sky
NGC 2298 is a compact globular cluster located in the constellation Puppis, a tightly bound spherical system of ancient stars orbiting in the outer halo of our galaxy. Unlike the showpiece globulars of the Milky Way, this cluster has a more condensed, jewel-like appearance, marked by a dense core surrounded by a finely resolved stellar halo.
The cluster lies at a distance of approximately 34,000 light-years and spans about 5 arcminutes on the sky, corresponding to a physical diameter of roughly 50–55 light-years. With an integrated visual magnitude near 9.3, it remains just beyond naked-eye visibility but reveals an extraordinary richness of individual stars when imaged at high resolution.
Structurally, NGC 2298 shows a pronounced central concentration with a steep brightness gradient into its inner core, while the outer regions dissolve into a sparse halo of faint members that blend seamlessly into the surrounding Milky Way field. Subtle color variations among its stars reflect a population dominated by old, low-metallicity suns, with occasional warmer and cooler outliers hinting at complex stellar evolution pathways within the cluster.
Astrophysically, NGC 2298 is a strongly metal-poor globular cluster, with an iron abundance nearly 80 times lower than that of the Sun, indicating that its stars formed from primordial gas only lightly enriched by earlier generations of supernovae. It is dynamically evolved and thought to have lost part of its original stellar envelope through long-term tidal interactions with the Milky Way, possibly after being accreted from a now-disrupted dwarf galaxy. What remains is a resilient remnant of the galaxy’s early assembly history, preserving stars that formed roughly 13 billion years ago, not long after the Milky Way itself began to take shape.
Imaged in LRGB on my Planewave CDK 1000 at Observatorio El Sauce, Chile
Image acquisition and processing: Mike Selby