TITLE: GCN CIRCULAR NUMBER: 31884 SUBJECT: GRB 220408A: GRANDMA observations DATE: 22/04/12 15:20:13 GMT FROM: Sarah Antier at OCA S. Beradze (AbAO), U. Bhardwaj (GRAPPA), T. Culino (ESILV), P. Hello (IJCLAB), M. Masek (FZU), G. Raaijmakers (GRAPPA), Y. Rajabov (UBAI), T. Sadibekova (AIM/CEA-UPS), F. Z. Guo (THU), X. F. Wang (THU/BJP), Y. Zhu (NAOC), J. Zhang (NAOC), D. A. Kann (HETH/IAA-CSIC), K. Noysena (TRT-SRO), C. Rinner (OUCA), Z. Benkhaldoun (OUCA), J. Zhu (BJP), X. Song (BJP), S. Antier (OCA/Artemis), P. A. Duverne (IJCLAB), A. Simon (Kyiv Univ), A. Baransky (Kyiv Univ) and V. Godunova (IC ICAMER) report on behalf of GRANDMA collaboration: The GRANDMA telescope network responded to the alert of GRB 220408A (Caputo et al. GCNC 31848). The first observations started 0.63 h after the SWIFT BAT trigger time. We did not detect the optical afterglow within the first 24 h. Upper limits are given in the AB system, at 3-sigma. T-T0(hr)| MJD������ | Observatory�� | Exposure| Filter | Upp. Lim. (AB) ___________________________________________________________________________ 0.63 |59677.26659|KNC-T19������������ |9*300 s�� |�� V ������ ���� |���� 17.7 1.82 |59677.31602|SRO�������������������� |7*60 s���� |�� R ������ ���� |���� 19.8 6.27 |59677.50176|Xinglong-2.16m|9*400 s�� |�� Rc������ ���� |���� 20.3 8.45 |59677.59259|BJP/ALi-50������ |21*20 s�� |�� Clear |���� 21.4 14.89|59677.86076|MOSS������������������ |45*60 s�� |�� Clear |���� 20.3 18.76|59678.02215|KNC-HAO������������ |23*180 s |�� Lumen |���� 20.6 These upper limits are consistent with previous reports of detections by UVOT (Caputo et al. GCNC 31848, Oates et al. GCNC 31855), KAIT (Zheng et al. GCNC 31850), LCO (R. Strausbaugh et al. GCNC 31862), NOT (Zhu et al. GCNC 31864), RATIR (Watson et al. GCNC 31870), and LDT (B. O'Connor et al. GCNC 31875), and the upper limits provided by MASTER (Lipunov et al. GCNC 31849), Xinglong-2.16m (Jiang et al. GCNC 31853), GIT (Kumar et al. GCNC 31857), LOAO/SAO/DOAO (Paek et al. GCNC 31867), and 1.3m DFOT (Kumar et al. GCNC 31868). The SRO, Xinglong-2.16m, and Ali-50 data have been calibrated with four stars from the Pan-STARRS catalog, using the transformations by Lupton (2005) and using Rc values for the Clear Al-50 observation. The MOSSm KNC-T19 and KNC-HAO images have been calibrated using field stars from the PanSTARRS-DR1 catalog, measured with the MUPHOTEN pipeline (Duverne et al. 2021). GRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr) devoted to the observation of transients in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS 497, 5518). Kilonova-Catcher (KNC) is the citizen science program of GRANDMA (http://kilonovacatcher.in2p3.fr/).