Optical Pulsations in Two SMC Be/X-ray Pulsars
ATel #1406; P. C. Schmidtke (Arizona State University), A. P. Cowley (Arizona State University)
on 3 Mar 2008; 22:34 UT
Credential Certification: Paul Schmidtke (Paul.Schmidtke@asu.edu)
Subjects: Optical, X-ray, Binary, Neutron Star, Pulsar
We have analyzed the MACHO and OGLE II light curves of
SXP25.5 (XMMU J004814.1-731003) and SXP327.
SXP25.5 (RA=00:48:14.1, Dec=-73:10:04.0) is identified with stars OGLE
II smc_sc4_i_171264 (I~15.6) and MACHO 212.15849.52 (R~15.6). The light
curves show strong non-radial pulsations (NRP) at 0.5983 days. Long-term
(hundreds of days) irregular ~0.1 mag variations are also present.
SXP327 (RA=00.52:52.5 Dec=-72:17:14.9) has been identified by M. Coe
(see www.astro.soton.ac.uk/~mjc/smc). It is MACHO star 207.16147.60
with R~16.5. The light curve shows two pulsation periods, with a very
strong period at P=0.9762 days and a second period at P=0.9364 days. In
addition, the MACHO light curve shows a slow downward trend of ~0.3 mag
over 7.5 years of observation.
