Color-contrasting double stars are stunning celestial jewels. Doubles like Albireo and Almach often steal the spotlight, but our galaxy is home to many contrasting pairs noteworthy for any backyard astronomer. One of them is 56 Herculis, featuring a bright orange star paired with a teal-looking dimmer star. So the next time you’re under spring or summer skies, turn your scope toward the Roman hero Hercules and take in colorful 56 Herculis.
Upon landing on 56 Herculis, observers are greeted by an orange (some say warm yellow) star. This primary star has a stellar classification of G8III and shines at a magnitude of +6.1. Nearby, at nearly 18 arcseconds away, lies a dim magnitude +10.8 companion with an alluring teal hue.1
Retired Navy Admiral William Henry Smyth first recorded 56 Herculis in 1838, most likely from his private observatory in Bedford, England, using his 5.9-inch refractor telescope.2 The author John Nanson provides an insightful take on the history of observations since 1838 on his Star Spliters site.
My Observations
| Date | June 20, 2024 |
| Time | 10:50 p.m. |
| Location | Seattle, WA |
| Magnification | 169x |
| Scope | Meade 8″ SCT |
| Eyepiece | 12mm |
| Seeing | Average |
| Transparency | Average |
On this summer solstice, the sunlight lingers deep into the night. Even now, as 56 Herculis falls into the eyepiece, a glow across the sky scares the dimmer stars away. The very dim teal companion is just sneaking into view.
I started using averted vision, and the star popped in brightness, putting off a blue-green color. These averted glimpses seem to saturate the orange and teal more, making this a delightful site on this new summer night.
Key Stats
| Constellation | Hercules |
| Best Viewing | Spring / Summer |
| Visual Magnitude | +6.1 | +10.8 |
| Separation | 17.9″ | 2450 AU |
| Position Angle | 92° |
| Spectral Class | A=G8III |
| Absolute Visual Magnitude | +.39 |
| Distance from Earth | 450 ly |
| Milky Way Location | Orion Spur |
| My Viewing Grade | A |
| Designations | SAO 84692, HD 152863, HR 6292, 56 Her, and HIP 82780, STF 2110 |
Sources and Notes
Banner adapted from an illustration created by Pablo Budassi. The illustration is licensed under the Creative Commons Attribution-Share Alike 4.0 International license. Full details here.
1 Stelle Doppie. (n.d.). ADS 11061 AB. Stelle Doppie. https://www.stelledoppie.it/index2.php?iddoppia=67953
2 Science Museum Group. (n.d.). William Henry Smyth. Retrieved June 27, 2024, from https://collection.sciencemuseumgroup.org.uk/people/ap28061/smyth-william-henry
Sketch by Wayne McGraw
The Garden Astronomer 