NGC 2506 is an open cluster in the constellation of Monoceros and is best viewed in the middle of winter.
Around 150 fainter stars (between magnitudes +10 to +14) combine to make NGC 2506 shine at +7.6 magnitude. Unfortunately, the cluster lies in an ocean of black as the area around it doesn’t have many stars. Without notable stars to light the path, finding NGC 2506 in light polluted skies may be tricky.
But the journey is worth it. Using binoculars or a small telescope, you’ll see a fuzzy patch. Moving up in telescope size (i.e., 6-inch or larger scopes) will gives you a richer experience as these scopes will bring out individual stars.1
As my observation below confirms, NGC 2506’s stars are faint and thus tougher to resolve. My area’s suburban light washes out these stars. I’m sure looking at the cluster from a pristine dark sky is a real treat, but I believe it’s still a worthy target for suburban observers surfing winter skies.
On a historical note, William Herschel discovered NGC 2506 on February 23, 1791.
My Observations
| Date | February 24, 2022 |
| Time | 8:40 p.m. |
| Location | Seattle, WA |
| Magnification | 102x |
| Scope | Meade 8″ SCT |
| Eyepiece | 20mm |
| Seeing | Average |
| Transparency | Average |
I was hoping to see more stars in this cluster. My skies are not crystal clear tonight, so I’m fighting against a good dose of sky glow. Even with my 8-inch scope, I’m only able to see a handful of stars. The cluster, at least with tonight’s skies, is so faint that I nearly passed by it. As I read the online history of this cluster, I realize I’m sketching NGC 2506 nearly 231 years after William Herschel first logged his observation.
Key Stats
| Constellation | Monoceros |
| Best Viewing | Winter |
| Visual Magnitude | +7.6 |
| Distance from Earth | 11,300 ly |
| Milky Way Location | Perseus Arm |
| My Viewing Grade | B |
Sources and Notes
- The banner photo of NGC 2506 is a screenshot by Roberto Mura from Stellarium. This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.
- 1 Freestarcharts.com. NGC 2506 – Open Cluster, https://freestarcharts.com/ngc-2506.
- Sketch by Wayne McGraw
- AKA: Caldwell 54, Melotte 80, Collinder 170
The Garden Astronomer 