“A Surprise Almost as Old as the Universe” –Hubble Detects Invisible Mass of Small Black Holes at Globular Cluster Core

    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 … Continue reading “A Surprise Almost as Old as the Universe” –Hubble Detects Invisible Mass of Small Black Holes at Globular Cluster Core