GCN Circular 31358
Subject
GRB 220101A: CAHA 2.2m/CAFOS detection
Event
Date
2022-01-01T22:29:15Z (4 years ago)
From
Alexander Kann at IAA-CSIC <kann@iaa.es>
A. de Ugarte Postigo (Obs. Cote d'Azur), D A. Kann (HETH/IAA-CSIC), C.
C. Thoene, M. Blazek (both HETH), J. F. Agui Fernandez (HETH/IAA-CSIC),
P. Martin, and I. Hermelo (both CAHA) report:
We observed the afterglow of GRB 220101A (Swift detection: Tohuvavohu et
al., GCN #31347; Fermi/LAT Detection: Arimoto et al., GCN #31350; AGILE
detection: Ursi et al., GCN #31354; afterglow detections: Kuin &
Tohuvavohu, GCN #31351; Fu et al., GCN #31353; Hentunen et al., GCN
#31356; Perley, GCN #31357; redshift z = 4.61: Fu et al., GCN #31353)
with CAFOS, mounted on the 2.2 m telescope, at the Calar Alto
Observatory (Almeria, Spain). The observation started at 19:35:31 UT on
01 January 2022 (13.47 hr after the GRB) and consisted of 6 x 90 s
integrations in the i' band.
The afterglow is well-detected in the individual images. Against
comparison stars from SDSS, we measure i' = 18.45 +/- 0.03 mag (AB) in
the stacked image at mid-time 0.60177 d after the trigger.
We note this is a very bright GRB and afterglow, further follow-up is
encouraged.