TITLE: GCN CIRCULAR NUMBER: 36050 SUBJECT: IceCube-240327B: GRANDMA/Kilonova-Catcher observations of 4FGL J0555.9+0030 and optical upper limits DATE: 24/04/08 07:51:37 GMT FROM: Damien Turpin at CEA-Saclay <dturpin-astro@hotmail.com> D. Turpin (CEA/irfu), M. Freeberg, Y. Jongen, S. Leonini, J.P. Vignes (KNC), S. Antier (OCA), T. Pradier (Unistra/IPHC), M. Coughlin (UMN), C. Andrade (UMN), P-A Duverne (APC), I. Tosta e Melo (UniCT-DFA), P. Hello (IJCLAB), N. Guessoum (AUS) on behalf of GRANDMA/Kilonova-Catcher collaboration: We observed the localization region of the neutrino event IceCube-240327B (Sommani et. al, GCN 35984, Mang et al., GCN 36005) using the Kilonova-Catcher telescope network. From T0+1.10 days to T0+4.37 days after the IceCube detection time, we do not detect any optical counterpart at the known gamma-ray source 4FGL J0555.9+0030 position (RA = 89.00 deg, Dec = 0.51 deg J2000), a potential gamma-ray source counterpart candidate (Sommani et. al, GCN 35984). This result is consistent with Stein et al. (GCN 35989), Pillas et al. (GCN 36026) In the following table, we report the preliminary photometry of our observations of 4FGL J0555.9+0030. T-T0 day | MJD | Telescope | Observer | Exposure | Filter | Upper limit (5 sigma) —------------------------------------------------------------------------------------------------ 1.10 | 60397.78045138 | Montarrenti 0.53m | S. Leonini | 3x180s | Rc | 18.9 (Vega) 1.31 | 60397.98425636 | PlaneWave CDK 17" | Y. Jongen | 1x180s | Rc | 20.1 (Vega) 1.34 | 60398.01371527 | iTel T72 | M. Freeberg | 10x180s | Rc | 20.2 (Vega) 1.37 | 60398.04372057 | Planewave CDK 400 | J.P. Vignes | 8x300s | Rc | 21.6 (Vega) 1.37 | 60398.04727383 | Planewave CDK 400 | J.P. Vignes | 8x300s | V | 21.2 (Vega) 1.38 | 60398.05080265 | Planewave CDK 400 | J.P. Vignes | 8X300s | B | 21.0 (Vega) 1.41 | 60398.08996527 | TEC160FL | M. Freeberg | 15X180s | g | 19.6 (AB) 1.45 | 60398.12474537 | TEC160FL | M. Freeberg | 15x180s | r | 18.8 (AB) 1.75 | 60398.42292824 | iTel T32 | M. Freeberg | 10x180s | V | 18.9 (Vega) 2.33 | 60399.00577655 | Planewave CDK 400 | J.P. Vignes | 1x300s | Rc | 20.8 (Vega) 2.34 | 60399.01318287 | iTel T72 | M. Freeberg | 10x180s | Rc | 20.1 (Vega) 2.37 | 60399.04641997 | Planewave CDK 400 | J.P. Vignes | 8x300s | V | 21.2 (Vega) 2.37 | 60399.04994587 | Planewave CDK 400 | J.P. Vignes | 8x300s | B | 21.0 (Vega) 3.33 | 60400.00561342 | iTel T72 | M. Freeberg | 10x180s | V | 20.0 (Vega) 4.33 | 60401.00523148 | iTel T72 | M. Freeberg | 10x180s | Rc | 19.7 (Vega) 4.37 | 60401.04116386 | Planewave CDK 400 | J.P. Vignes | 8x300s | Rc | 21.7 (Vega) 4.37 | 60401.04471439 | Planewave CDK 400 | J.P. Vignes | 8x300s | V | 21.1 (Vega) 4.37 | 60401.04824406 | Planewave CDK 400 | J.P. Vignes | 8x300s | B | 20.9 (Vega) Johnson filters have been calibrated using the Gaia DR3 catalog while the AB mag. have been calibrated using the PanSTARRS nearby stars. All the data have been reduced by a single data processing pipeline STDPIPE (Karpov et al., 2022). We also run subtracted detection pipeline from Karpov et al., 2022, on the deepest images obtained at T0+1.38, T0+1.37 and T0+4.37 days in the B, V and Rc filters respectively. We do not detect any credible optical transient candidate down to the limiting magnitude reported in the above table. The frame are centered at RA = 88.93967° DEC = 0.51029 with an error radius ~ 21 arcmin. GRANDMA is a worldwide coordinated telescope network (grandma.ijclab.in2p3.fr) devoted to the observation of transients in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS497, 5518). Kilonova-Catcher (KNC) is the citizen science program of GRANDMA (http://kilonovacatcher.in2p3.fr/). View this GCN Circular online at https://gcn.nasa.gov/circulars/36050. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...