TITLE:   GCN CIRCULAR
NUMBER:  35463
SUBJECT: GRB 240101B: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
DATE:    24/01/02 20:34:34 GMT
FROM:    I. Peretto at MarSEC (Marana Space Explorer Center) <ricerca@marsec.org>

Ivo Peretto (MarSEC, Marana Space Explorer Center, Marana Di Crespadoro, VI, Italy)

Member of:
UAI/SSV - Unione Astrofili Italiani/Sezione Stelle Variabili, GRB section.
AAVSO (American Association Variable Stars Observers)

In collaboration with: Stefano Lora (MarSEC, Marana Space Explorer Center, Marana di Crespadoro, VI, Italy)

report:
We imaged the field of GRB 240101B detected by SWIFT(trigger=1205744)
with the telescope  14” RC Officine Stellari of MarSEC (Marana Space Explorer Center).

The observations with a series of 120 sec exposures started at 2024-01-01 21:42:43 UT, 77 min. after the GRB trigger, with a Ritchey-Chretien telescope D=360 mm f/ 8.

at the following position:

RA(J2000) = 23h 28m 12s
Dec(J2000) = +51d 38' 43"

Weather conditions were medium with Moon illuminated 70% at 2° from the horizon.

We co-added 30 exposures of 120 sec each.

Start T0+      End T0+       V lim.
 77 min          137 min       20.12

We did not found any optical counterpart in A.R. 23 28 12, DEC. +51 38 43 position and in the error box of the XRT candidate.
ref.: S. B. Cenko (GSFC) et al., GCN Circular 35449

Magnitudes were estimated with the Gaia DR3  and
are not corrected for galactic dust extinction.

Reference:
https://www.marsec.org/

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