TITLE:   GCN CIRCULAR
NUMBER:  35277
SUBJECT: GRB 231205A: DDOTI Upper Limits on the Afterglow
DATE:    23/12/06 01:21:44 GMT
FROM:    Kin O. C. L. Mendoza at Instituto de Astronoma, UNAM <koclopez@astro.unam.mx>

Océlotl Lopez (UNAM), Alan M. Watson (UNAM), Rosa L. Becerra (UNAM),
Margarita Pereyra (UNAM), Nat Butler (ASU), Simone Dichiara (Penn state
university), Diego Gonzalez (UNAM), William H. Lee (UNAM), Alexander
Kutyrev (GSFC/UMD), Srihari Ravi (ASU) and Eleonora Troja (Tor Vergara
Roma) report:



We observed the field of the Fermi GBM GRB 231205A (Fermi GBM Team, GCN
Circ. 35263) with the DDOTI wide-field imager at the Observatorio
Astronómico Nacional on Sierra San Pedro Mártir (
http://ddoti.astroscu.unam.mx) from 2023-12-05 12:55:13 to 13:10:57 UTC
(10.50 to 11.75 hours after the trigger).


We observed a region of 7 degrees in RA by 7 degrees in declination
centered on the Fermi GBM Final Position of RA = 206.1 and Dec = 22.8
(J2000 degrees). This region contains 1 instrumental field or about 49
square degrees. We obtained 13.6 minutes of exposure per instrumental field
in the w filter. We obtained AB photometry by calibration against the APASS
catalog.


We detect no likely candidates for the afterglow to our 10-sigma upper
limits of w = 18.89-19.41 (inter-quartile).


We thank the staff of the Observatorio Astronómico Nacional on San Pedro
Mártir.