{
  "bibcode": "2022GCN.31358....1D",
  "body": "A. de Ugarte Postigo (Obs. Cote d'Azur), D  A. Kann (HETH/IAA-CSIC), C. \nC. Thoene, M. Blazek (both HETH), J. F. Agui Fernandez (HETH/IAA-CSIC), \nP. Martin, and I. Hermelo (both CAHA) report:\n\nWe observed the afterglow of GRB 220101A (Swift detection: Tohuvavohu et \nal., GCN #31347; Fermi/LAT Detection: Arimoto et al., GCN #31350; AGILE \ndetection: Ursi et al., GCN #31354; afterglow detections: Kuin & \nTohuvavohu, GCN #31351; Fu et al., GCN #31353; Hentunen et al., GCN \n#31356; Perley, GCN #31357; redshift z = 4.61: Fu et al., GCN #31353) \nwith CAFOS, mounted on the 2.2 m telescope, at the Calar Alto \nObservatory (Almeria, Spain). The observation started at 19:35:31 UT on \n01 January 2022 (13.47 hr after the GRB) and consisted of 6 x 90 s \nintegrations in the i' band.\n\nThe afterglow is well-detected in the individual images. Against \ncomparison stars from SDSS, we measure i' = 18.45 +/- 0.03 mag (AB) in \nthe stacked image at mid-time 0.60177 d after the trigger.\n\nWe note this is a very bright GRB and afterglow, further follow-up is \nencouraged.",
  "circularId": 31358,
  "createdOn": 1641076155000,
  "email": "kann@iaa.es",
  "subject": "GRB 220101A: CAHA 2.2m/CAFOS detection",
  "submitter": "Alexander Kann at IAA-CSIC  <kann@iaa.es>",
  "eventId": "GRB 220101A"
}