NGC 5897 is a globular cluster in Libra. It is about 41,000 light years away and has relatively low density compared to most globular clusters. It spans about 170 light years (though like galaxies, globulars have no true edge).

The stars have a very low metallicity, only 0.91% of our sun indicating that these stars formed a long time ago. Metallicity is a measure of the amount of elements heavier than helium in a star. Higher metallicity values indicate that the star is younger because there hadn’t been time for heavier elements to be formed

This 10h 40m of RGB data. You can find all the technical details on astrobin.