GCN Circular 31363
Subject
GRB 220101A: Asiago spectroscopic and photometric detection
Date
2022-01-02T01:19:25Z (2 years ago)
From
Lina Tomasella at INAF,Padova <lina.tomasella@inaf.it>
L. Tomasella (INAF-OAPadova), E. Brocato (INAF-OAAbruzzo), M. D���Onofrio (DFA UniPd), E. Cappellaro, S. Benetti (INAF-OAPadova)
On behalf a larger collaboration report:
We observed the optical counterpart of GRB 220101A (Tohuvavohu et al.,
GCN 31347; Arimoto et al., GCN 31350) using the Asiago Copernico and Schmidt Robotic telescopes (INAF-OAPadova).
The Copernico Telescope is equipped with the AFOSC spectrograph. A low S/N spectrum was obtained starting on 2022-01-01 UT 22:21:03, covering the wavelength range 3400-8200 AA.
As reported by Fu at al., GCN 31353 and by Fymbo et al., GCN 31359, a deep, broad feature is detected around 6800 AA, interpreted as the damped Lyman alpha. Other narrow absorption lines are also detected, which allow to confirm the GRB redshift z = 4.61
The afterglow was observed starting on 2022-01-01 between 22:01 and 22:05 UT using Copernico Telescope with BV filters and with gri Sloan filters (two series) using Schmidt 67/92 Robotic Telescope between 22:08 and 22:25 UT.
The afterglow is detected in several individual images.
We measure V-Bessel = 20.48 +/- 0.1 mag in the Copernico image taken at UT 22:01.
The spectral and photometric analysis results presented above are preliminary; data analysis is ongoing.