If you take a quick look at any list of top astronomical targets in the constellation Lyra, you might notice that this colorful double often gets overlooked. This is understandable because there are so many wonderful objects around it! You have brilliant Vega, the famous “Double-Double” of Epsilon Lyrae, the awesome Ring Nebula, the quaint Eta Lyrae (Aladfar), and the other double-double of Struve 2470! Seriously, there’s a whole star party happening up there!
Otto Struve 525 (aka STT 525) is a triple-star system that features a golden primary (Star A) with two companions (stars B & C). Stars A & B are very close together, only separated by 1.8 arcseconds. I could not separate A & B from my location. However, the pale orange primary star has a pretty blue companion (Star C) 45 arcseconds away. Stars A & C form a striking orange and blue pair that can be easily split in most scopes. This post on Cloudy Nights provides some photos and discussion on this nice system.
My Observations
| Date | October 28, 2023 |
| Time | 8:49 p.m. |
| Location | Seattle, WA |
| Magnification | 169x |
| Scope | Meade 8″ SCT |
| Eyepiece | 12mm |
| Seeing | Above Average |
| Transparency | Above Average |
Based on my research, I have discovered a star that is located very close to the golden primary star I am currently observing. Unfortunately, the current conditions are not favorable for me to view this star, but I will attempt again with higher magnification. Nonetheless, I still appreciate the beauty of the golden-orange star beside a blue, dimmer star.
Key Stats
| Constellation | Lyra |
| Best Viewing | Summer |
| Visual Magnitude | +6.1 | +7.6 (stars a&c) |
| Separation | 45.4″ |
| Position Angle | 349° |
| Distance | 1169 ly |
| My Viewing Grade | B+ |
| Designations | SAO 67566 |
Sources and Notes
18549+3358 STT 525 AB (HD 175635). WDS 18549+3358 STT 525 AB (HD 175635). (n.d.). https://www.stelledoppie.it/index2.php?iddoppia=77780
Sketch by Wayne McGraw
The Garden Astronomer 