The early-type near-contact binary system V337 Aql revisited

• New BVR light curves of V337 Aql have been obtained.
• Long-term orbital period variation of the system has been studied.
• The multi-color light curves together with published radial velocities were analyzed.
• Absolute parameters of the components were estimated.

The close binary V337 Aql consists of two early B-type components with an orbital period of 2.7339 d. New multi-band photometric observations of the system together with published radial velocities enabled us to derive the absolute parameters of the components. The simultaneous light and radial velocity curves solution yields masses and radii of M1 = 17.44 ± 0.31 M⊙ and R1 = 9.86 ± 0.06 R⊙ for the primary and M2 = 7.83 ± 0.18 M⊙ and R2 = 7.48 ± 0.04 R⊙ for the secondary component. Derived fundamental parameters allow us to calculate the photometric distance as 1355 ± 160 pc. The present analysis indicates that the system is a near-contact semi-detached binary, in which a primary star is inside its Roche lobe with a filling ratio of 92% and the secondary star fills its Roche lobe. From O–C data analysis, an orbital period decrease was determined with a rate of −7.6 × 10−8 yr−1. Kinematic analysis reveals that V337 Aql has a circular orbit in the Galaxy and belongs to a young thin-disc population.