With many competing targets in the Orion neighborhood, it may be easy to overlook notable double stars such as Rigel and Struve 747 (also known by HR 1887). Struve 747 is a 4th magnitude double star in Orion and a worthy target on any winter night. When observing the pair, you’ll notice they are pretty wide apart, which makes sense as they are 17,900 AU apart.
My Observations
January 22, 2021 | 8:52 p.m.
Seattle, Washington, USA
Meade LX65 8″ ACF, 18mm eyepiece
The 747 double is pretty. The two stars look almost identical with an attractive light blue color. The pair is wider than other doubles I’ve viewed, so a lower eyepiece power (in my case 18mm) is fine.
Key Stats
| When to view | Winter | R.A. (2021) | 05h 36m 03.80s |
| Constellation | Orion | Dec (2021) | −05° 59′ 20.4″ |
| Visual Magnitude | +4.76 and +5.51 | Distance | 1600 ly |
| Absolute Magnitude | -6.87 | Age | Unknown |
| Period | Unknown | Milky Way Locations | Orion Spur |
| Diameter | 7.8 Suns | My Viewing Grade | B |
The Garden Astronomer 