Optical observations of Swift J1753.5-0127
ATel #7813; K. Wiersema (Leicester)
on 20 Jul 2015; 09:28 UT
Credential Certification: Klaas Wiersema (kw113@star.le.ac.uk)
The Swift/BAT Transient Monitor shows a slow increase in brightness for Swift J1753.5-0127, after spending a few months at (near) undetectable BAT flux levels (http://swift.gsfc.nasa.gov/results/transients/SWIFTJ1753.5-0127/).
In response, we observed this source with the University of Leicester 0.5m telescope at Oadby, UK, at midtime 22:49 UT on 2 July 2015 (MJD 57205.9511). We find the following magnitudes:
B=17.56+-0.07, V=17.02 +- 0.07, r=17.02+-0.08, i=16.59+-0.07 (magnitudes calibrated using APASS values for field stars).
These are more or less consistent with the measurements reported by Neustroev et al. (ATel #7697), indicating no strong optical response to the change in hard X-rays over the interval between the measurements of Neustroev et al and ours.