Struve 2446: A Quaint Yellow and White Binary in Aquila

During late summer and early autumn nights, backyard astronomers can focus on the constellation Aquila (the Eagle) and discover several celestial wonders, including the binary star Struve 2446. The 19th-century astronomer Friedrich Georg Wilhelm von Struve cataloged this pair of stars in 1825.

The combined apparent magnitude of Struve 2446 is approximately 6.5, making it visible to the naked eye under optimal dark-sky conditions. However, a small telescope will allow you to see the two stars as distinct points of light, separated by 9.4 arcseconds. The primary star, known as Struve 2446 A, is pale yellow and shines at a magnitude of 6.9, with a spectral class of F5. The dimmer secondary star, Struve 2446 B, is two magnitudes fainter at 8.9.

Struve 2446 may not exhibit a striking contrast like colorful doubles in summer such as Albireo, but the two stars offer a rewarding experience for all observers using a telescope.

My Observations

On this late summer evening, I’m enjoying exploring the night sky as I target some lesser-known double stars. One of these is Struve 2446. I can quickly and clearly split the two stars using 169x magnification. However, I’m having some difficulty determining the color of the brighter primary star. At first glance, I believe it appears pale yellow, but as I squint and observe for a longer duration, I wonder if it might actually be a pale orange. The color of the secondary star seems to be off-white.

Key Stats

Sources and Notes

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Stelle Doppie. (n.d.). Struve 2446. Retrieved October 30, 2023, from https://www.stelledoppie.it/index2.php?iddoppia=78833

Sketch by Wayne McGraw