TITLE:   GCN CIRCULAR
NUMBER:  32227
SUBJECT: GRB 220617A: TNG optical observations
DATE:    22/06/19 12:17:15 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <pda.davanzo@gmail.com>

P. D'Avanzo (INAF-OAB), S. Piranomonte (INAF-OAR), S. Campana (INAF-OAB), V. D'Elia (ASI/SSDC), 
L. Di Fabrizio, A. Garcia De Gurtubai Escudero (INAF-TNG) on behalf of the CIBO collaboration report:

We observed the field of the short GRB 220617A (Fermi-GBM detection: Fermi GBM Team, GCN Circ 32209; 
Fermi-LAT detection: Di Lalla et al., GCN Circ 32212; IPN detection: Kozyrev et al., GCN Circ. 32220) with the 
Italian 3.6m TNG telescope equipped with the optical camera DOLORES. A series of images were obtained with 
the r-sdss filter on 2022-06-18 from 21:22:18 UT to 22:09:26 UT (i.e. at a mid time of about 1.14 days after the burst).  

The pointing enabled to image the location of the Swift-XRT sources #3 and #4 (Page et al., GCN Circ. 32215), 
both consistent with the Fermi/LAT error circle.

No clear afterglow candidate is detected within the error circles of XRT sources #3 and #4 down to a typical limiting 
magnitude of r ~ 24.5 (AB; calibrated against the SDSS catalogue). 


We note the presence of catalogued galaxies from the SDSS within the error circles of the XRT sources #3 and #4: 

XRT3
- SDSS J102809.40+152924.9 (photo-z = 0.102 +/- 0.031)
- SDSS J102809.54+152915.8 (photo-z = 0.381 +/- 0.083)

XRT4
- SDSS J102757.23+152645.6 (photo-z = 0.714 +/- 0.116)