GCN Circular 36050

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
Not found
 
 
, Mang et al., GCN 36005
Not found
 
 
) 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
Not found
 
 
). This result is consistent with Stein et al. (GCN 35989
Not found
 
 
), Pillas et al. (GCN 36026
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)

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/).