SIMBAD references

R. M. Wagner, LBT Observatory; S. G. Starrfield and J. Rohrbach, Arizona State University; H. Bond, Space Telescope Science Institute; A. Karam, University of Arizona; B. Monard, Bronberg Observatory; G. Bolt, Craigie, Australia; and R. Ishioka, M. Uemura, and T. Kato, Kyoto University, report: "A comparison of optical photometry, obtained contemporaneously with Chandra x-ray observations in April and July, reveals a substantial change in the optical light curve of this classical nova and super-soft-x-ray source. Unfiltered photometry obtained on July 18, 19, and 21 and B-band photometry obtained at Cerro Tololo (1.3-m reflector + AndiCam) on July 19 show a sinusoidal modulation of amplitude 0.2 mag with a period of 0.281 ± 0.003 day, which is likely to be the orbital period. Minimum light corresponds to JD 2452839.321. Another variation with a period of 69 ± 3 min is superposed on the orbital modulation. Photometry obtained at Cerro Tololo with the same equipment on seven nights between Apr. 5.3 and 20.4 UT shows erratic variations that are not periodic or consistent with the July results. No statistically significant variation is detected near the x-ray period of 1325 s (Ness et al. 2003, http://xxx.lanl.gov/abs/astro-ph/0308017) or at twice this period. The recent photometric behavior is similar to some intermediate polar cataclysmic variables. Additional observations are encouraged."