GCN Circular 15393
J. R. Cummings and Valerio D'Elia on behalf of the Swift science team Swift-BAT trigger 575905 (Cenko et al., GCN 15384) is probably due to a fluctuation in the image domain, not to any astrophysical source. While the BAT significance level (7.0 sigma) usually is high enough to indicate a real source, in this case the peak in the image is not robust with respect to very slight changes in parameters. The total XRT exposure for this field is 15ks. The source number 2 reported in Izzo et al. (GCN 15388), that was uncatalogued but below the RASS limit, has a bright star as optical counterpart. We thus conclude that source 2 is not related to the BAT emission, and that the slight variability observed for this object in the X-ray band is due to normal stellar activity.