A Hexagonal Galactic Center

NGC 7020, a barred lenticular galaxy in the southern constellation Pavo, holds a geometric mystery. Clear but subtle in this image from Gemini South, one half of the International Gemini Observatory, a Program of NSF NOIRLab, the core of NGC 7020 is visibly hexagonal in shape. A hexagon is not a common shape for any celestial body, let alone an entire galaxy. To form a hexagonal structure such as this, a considerable number of stars must orbit in a very narrow band. This orbital path includes two denser regions of stars seen on the left and right sides of the hexagon, which are known as “ansae”. NGC 7020’s unusual shape seems to be the product of a very rare orbital resonance, or an as-yet-unknown phenomenon. 

The 8-meter Gemini South telescope is located on Cerro Pachón in the Chilean Andes. Along with the other half of the international Gemini observatory, Gemini North in Hawai‘i, these two telescopes give us a deep view of the entire night sky.