GCN Circular 38779
Subject
GRB 250101A: LCO optical counterpart detection
Event
Date
2025-01-02T16:56:31Z (9 months ago)
From
ankur ghosh at CAPP, University of Johannesburg <ghosh.ankur1994@gmail.com>
Via
Web form
Ankur Ghosh, Soebur Razzaque (CAPP, University of Johannesburg), Rahul Gupta (NASA GSFC), Alexander Moskvitin, Yulia Sotnikova (SAO RAS), Naveen Dukiya (ARIES) on behalf of a larger collaboration.
We observed the field of the GRB 250101A triggered by Swift (Page et. al., GCN 38752) in B, V filter of the 1-meter Sinistro telescope at the Las Cumbres Observatory Global Telescope (LCOGT) node located at McDonald Observatory. The 1-m Sinistro telescope is equipped with a 4K x 4K CCD (FOV: 26 x 26 arcmin, scale: 0.39 arcsec/pixel).
Observations began on January 02, 2025, starting from 14.48 hours after the GRB trigger.
We clearly detect the optical transient (OT) reported by GCNs (Li et al., GCN 38753; Mohan et al., GCN 38754; Zhu et al., GCN 38755; Budnev et al., GCN 38756; Wu et al., GCN 38758; Moskvitin et al., GCN 38762; Odeh et al., GCN 38763, Hu et al., GCN 38764; D'Avino et al., GCN 38768; Escudero-Coca et al., GCN 38769, Coca et al., Zhang wt al., GCN 38774, Komesh et al., GCN 38777) in our B, V band image.
|Date| |UTstart| |t-T0 (hours)| |Exp (sec)| |Filter| |Magnitude|
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2025-01-02 03:51:30.528 14.48 1 x 900 V V = 20.61 +/- 0.04
2025-01-02 06:19:33.312 16.95 2 x 1200 B B = 21.82 +/- 0.03
The field was calibrated against nearby APASS stars, with magnitudes converted using Lupton (2005) equations, and has not been corrected for Galactic extinction.