U Aquilae is a binary star system in the constellation Aquila, Located approximately 614 parsecs (2,000 ly) away from Earth.
The primary star (component A) is a yellow supergiant with a radius of 55 R☉ and a luminosity of 2,570 L☉. The secondary (component B) is a blue main-sequence star, twice the mass of the sun and around thirty times more luminous. It is hotter than the primary star at 9,300 K, but much smaller and fainter. The two stars orbit every five years and their separation varies from five to seven astronomical units in a mildly eccentric orbit.
u Aql A is a classical Cepheidvariable star ranging between magnitudes 6.08 and 6.86 over a period of 7.02 days. It is an evolved star which has exhausted its core hydrogen and is now fusing helium into carbon.[10]
^ abcDucati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237: 0. Bibcode:2002yCat.2237....0D.
^ abSamus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.