QS Aquilae
QS Aquilae is a bright, complex star system in the constellation Aquila. It’s barely visible to the naked eye, with its brightness ranging from about magnitude 5.93 to 6.06.
The system is made up of at least three stars. The inner pair forms an eclipsing binary, meaning two hot, blue stars orbit each other every 2.513 days and periodically block each other’s light, causing regular dips in brightness. A third star orbits this inner pair every about 77 years at a wide distance, making QS Aquilae a triple-star system. There is also some evidence for a possible fourth component with an orbital period of roughly 18 years, though this isn’t yet firmly confirmed.
The star’s variability was discovered in 1930 by Paul Guthnick and Richard Prager, and it was given its variable-star designation in 1934.
This page was last edited on 2 February 2026, at 15:12 (CET).