SUNSET: 
0
Photographer:
Bruce Waddington
Location of Photo:
SkyPi Remote Observatory, New Mexico
Date/Time of photo:
12/31/2024
Equipment:
12.5" Planewave scope with QSI-64ws camera
Description:
NGC 2158 is a dense open cluster in Gemini, the "little brother" to M35. Once thought to be a globular cluster because of its size and density, it is now known to be an intermediate-age, metal-poor open cluster that is a member of the old thin disk population. Most open clusters are disrupted by tidal forces in only a few million years yet this cluster is thought to be nearly 2B years old. As a result, its original hot blue stars have evolved off the main sequence leaving behind a redder population of stars.
