16 Cygni is a double star system in the constellation Cygnus. It’s best viewed in summer through early autumn. By the way, Cygnus is also known as the Northern Cross. 16 Cygni is the right-hand star in the cross. With a small telescope, you’ll be able to see this nice pair of sun-like stars.
16 Cygni comes with some surprises. Most notably, astronomers believe the binary includes an exoplanet companion that makes one orbit every 799 days and has a mass of 2.4 Jupiters!1
My Observations of 16 Cygni
| Date | December 5, 2020 |
| Time | 6:05 p.m. |
| Location | Seattle, WA |
| Magnification | 127x |
| Scope | Meade 8″ SCT |
| Eyepiece | 16mm |
| Seeing | Above Average |
| Transparency | Above Average |
This is a pretty double yellow. I’m at first surprised how well the color yellow resolves in the scope. As I stare for a minute, I reflect on how close this system is to me. It’s so close at a mere 69 light-years, yet so far as one contemplates the distance of one light-year.
Other Dates Observed:
- October 8, 2021 at 10:25 p.m.
Key Stats
| Constellation | Cygnus |
| Best Viewing | Fall |
| Visual Magnitude | +5.9 | +6.2 |
| Absolute Visual Magnitude | +4.1 |
| Distance from Earth | 69 ly |
| Separation | 39.8″ | 839 AU |
| Orbital Period | 13512 years |
| Milky Way Location | Orion Spur |
| My Viewing Grade | A |
Sources and Notes
Photo of 16 Cygni by David Ritter as licensed under the Creative Commons Attribution-Share Alike 4.0 International license.
1 Argyle, Robert W., et al. “16 Cygni.” An Anthology of Visual Double Stars, Cambridge University Press, Cambridge, 2019, p. 85.
The Garden Astronomer 