GCN Circular 17655

Daniele Malesani (DARK/NBI), Dong Xu (DARK/NBI), Pall Jakobsson (Univ. 
Iceland) and Jussi Harmanen (NOT and Univ. Turku) report on behalf of 
a larger collaboration:

We observed the field of GRB 150323C (Amaral-Rogers et al., GCN 17621
Not found
 
 
; 
Stanbro, GCN 17627
Not found
 
 
) using the Nordic Optical Telescope (NOT) located in 
La Palma. The mean time of the observation was March 28.21 UT, that is 
4.49 days after the GRB. A 20 min exposure was collected using the SDSS 
r filter.

Close to the position of the optical afterglow (Xu et al., GCN 17625
Not found
 
 
; 
Watson et al., GCN 17632
Not found
 
 
), we detect an object with r = 23.6 +- 0.2 AB 
(calibrated against nearby SDSS stars). This source is also marginally 
detected in the archival SDSS images with a comparable (though 
uncertain) brightness, and therefore an underlying galaxy must be 
contributing a significant fraction of the light.

We note a small, but significant offset between the afterglow and the 
galaxy positions. By registering astrometrically the afterglow image by 
Xu et al. (GCN 17625
Not found
 
 
) with the new NOT data, we find an offset of 
approximately 0.65". Such an offset is not unprecedented, so that the 
SDSS/NOT object is still a viable host galaxy candidate for GRB 150323C.

[GCN OPS NOTE(30mar15):  Per author's request, JH's affiliation was changed.]