S.Y. Fu, Z.P. Zhu, D. Xu, X. Liu (NAOC) report on behalf of a larger
We checked the archives of Legacy Survey (LS), PanSTAR, and SDSS for GRB
210610B (Page et al., GCN 30170). From the LS, the GRB optical afterglow
(e.g., Page et al., GCN 30170) is positionally located in a bright
nucleus, which lies in the south-eastern part of an extended source in
the direction of NorthWest-SouthEast.
The source has the multi-band photometric magnitudes g = 22.97, r =
22.87, z = 22.57, and a redshift z_ph = 0.96 +/- 0.44 from LS, and also
PSF magnitudes g = 24.32 +/- 0.5 , r = 23.09 +/- 0.12, i = 24.33 +/-
0.47, z = 23.61 +/- 0.69 from PanSTAR. The source is marginally detected
by SDSS, and we measure its magnitude r ~22.8. The r-band magnitudes
from three surveys are basically consistent with each other, considering
difference of photometric methods. The LS's z_ph = 0.96 +/- 0.44 is also
consistent with the spectroscopic tentative redshift z=1.13 of the GRB
optical afterglow from the NOT (Fynbo et al., GCN 30182).
We thus think the source is likely the host galaxy of the GRB.