No detected increase in the X-ray activity of B[e]/X-Ray system CI Cam/XTE J0421+560

ATel #9639; E. S. Bartlett (European Southern Observatory), J. S. Clark (Open University), L. J. Townsend (University of Cape Town)
on 17 Oct 2016; 03:46 UT
Credential Certification: Elizabeth Bartlett (ebartlet@eso.org)

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On October 16th, 2016 UT22:20, Swift took a 1ks target-of-opportunity observation of XTE~J0421+560/CI Cam, reported to be in optical outburst by Wijngaarden et al. (2016; ATel #9634). 11 counts were detected in a 20 arcsecond radius region centred on the position of CI Cam. Too few counts were detected to extract a spectrum capable of model fitting, but assuming the same parameters as reported by Bartlett et al, (2013; nH~5E+23 cm^-2, photon index~1.0) this count rate corresponds to an X-ray flux of 3.2E-12 ergs/cm^2/s. We note that this flux value is NOT background subtracted and so will include a small contribution from the X-ray background. This value is broadly consistent with the background subtracted, 3.0-10.0 keV quiescent flux value of CI Cam (1.36+/-0.05)E-12 ergs/cm^2/s, reported in the same publication, suggesting that this optical outburst, as yet, has no associated X-ray emission despite its similarities with the 1998 outburst. As such, this increase in optical activity does not appear be due to an accretion induced event related to the compact companion (e.g. the thermonuclear runaway on a white dwarf surface). We also note that no detection of the source has been reported by the MAXI all sky monitor at higher energies. We recommend further monitoring of the source at all wavelengths to shed further light both the current and historic activity of this intriguing source.