The Orbital Period of Swift J1626.6-5156

Abstract

We present the discovery of the orbital period of Swift J1626.6-5156. Since its discovery in 2005, the source has been monitored with Rossi X-ray Timing Explorer, especially during the early stage of the outburst and into the X-ray modulating episode. Using a data span of $\sim$700 days, we obtain the orbital period of the system as 132.9 days. We find that the orbit is close to a circular shape with an eccentricity 0.08, that is one of the smallest among Be/X-ray binary systems. Moreover, we find that the timescale of the X-ray modulations varied, which led to earlier suggestions of orbital periods at about a third and half of the orbital period of Swift J1626.6-5156.

12 pages, 4 figures, accepted for publication in ApJ

References in corpus (3)

• Rapid spectral and timing variability of Be/X-ray binaries during type II outbursts
• Bright flares from the X-ray pulsar SWIFT J1626.6-5156
• Recent RXTE/ASM and ROTSEIIId Observations of EXO 2030+375

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• On the orbital parameters of Be/X-ray binaries in the Small Magellanic Cloud
• The X-ray properties of Be/X-ray pulsars in quiescence
• The Be/X-ray Binary Swift J1626.6-5156 as a Variable Cyclotron Line Source
• Discovery of a Glitch in the Accretion Powered Pulsar SXP 1062
• Discovery of the 5 keV cyclotron line followed by three harmonics in SwiftJ1626.6-5156
• Timing and X-ray Spectral Features of Swift J1626.6-5156
• Catalog of the Galactic population of X-ray pulsars in High-mass X-ray binary systems
• Multi-frequency observations of SWIFT J1626.6-5156
• AstroSat observations of the Be/X-ray binary XTE J1946+274 during 2018 and 2021 outbursts