Binary period in Optical counterpart to XMMU J004723.7-731226 (SXP 264)
ATel #405; W. R.T. Edge, M. J. Coe and J. L. Galache (Southampton University)
on 5 Feb 2005; 18:03 UT
Credential Certification: W R T Edge (wrte@astro.soton.ac.uk)
Subjects: X-ray, Binary, Transient, Pulsar
A probable binary period has been detected in the optical counterpart to the X-ray source XMMU J004723.7-731226 = RXJ0047.3-7312 = AXJ0047.3-7312= SXP 264 in the Small Magellanic Cloud. This source has been identified with the emission line star [MA93]172 and is coincident with Optical Gravitational Lensing (OGLE) objects 116979 (Phase II) and 45007 (Phase III) (Udalski et al., 1998). We find an optical period of 48.8 +/- 0.6 days in the OGLE data. The modulation has an amplitude of 0.04 mag and a steep rise/slow decay profile similar to other confirmed X-ray binary systems. The relationship between this orbital period and the pulse period of 264s is within the normal variance found in the Corbet diagram (Corbet, 1984).
