Optical Pulsations in the Proposed Counterpart of CXOU J005446.3-722523
ATel #2998; P. C. Schmidtke (Arizona State University), A. P. Cowley (Arizona State University)
on 1 Nov 2010; 21:51 UT
Credential Certification: Paul Schmidtke (Paul.Schmidtke@asu.edu)
Subjects: Optical, X-ray, Binary, Neutron Star, Variables, Pulsar
Referred to by ATel #: 7831
A tentative X-ray pulsar, with a 4693 s pulse period, was found in Chandra data of the SMC
by Laycock et al. (2010, ApJ, 716, 1217). They proposed the optical counterpart is
emission-line star [MA93] 798 (Meyssonnier & Azzopardi 1993, A&AS, 102, 451).
We have identified this star with entries smc_sc7_i_70843 in OGLE-II and 207.16259.37 in
MACHO online databases. The light curves show a slow, gradual brightening,
with very small scatter. Period analysis reveals no evidence for an orbital period, but weak
pulsations at P=0.730 days are present in both data sets. Such periodic signatures are often
seen in Be stars, including Be/X-ray pulsars.