GCN Circular 17593
D. Xu (DARK/NBI), D. Malesani (DARK/NBI), P. Blay (IAC, NOT), P. Jakobsson (Univ. Iceland), report on behalf of a larger collaboration: We observed the field of the Swift GRB 150317A (Siegel et al., GCN 17592) with the NOT equipped with the AlFOSC camera. A single 300-s R-band exposure was secured, starting at 04:48 UT (25 min after the GRB). No new sources are detected within the X-ray position reported by Siegel et al. (GCN 17592), but we remark that in our image the bright glare from the nearby R=11 USNO star 1454-0197654 covers part of the XRT error circle. The limiting magnitude of our image is R ~ 21.5, but it is considerably shallower in the regions contaminated by the star PSF. It cannot be excluded at the present time that the X-ray source detected by XRT is due to the USNO star. Visual inspection of the BAT error circle also does not reveal any new object compared to archival DSS and SDSS images, down to R = 21.5.