TITLE: GCN CIRCULAR NUMBER: 21931 SUBJECT: LIGO/Virgo G298048: Summary of Pi of the Sky observations DATE: 17/09/26 21:17:49 GMT FROM: Adam Zadrozny at Pi of the Sky T. Batsch, A.J. Castro-Tirado, H. Czyrkowski, A. Æwiek, M. Æwiok, R. D±browski, M. Jelínek, G. Kasprowicz, A.Majcher, K. Ma³ek, L. Mankiewicz, K. Nawrocki, £. Obara, R. Opiela, L. W. Piotrowski, M. Siudek, M. Soko³owski, R. Wawrzaszek, G. Wrochna, A. Zadro¿ny, M. Zaremba, A.F. ¯arnecki (Pi of the Sky Collaboration) Pi of the Sky robotic wide field of view telescopes search for the possible EM transients in the sky scans performed twice a night. Each of the two observation sites (South telescope in Chile and the North one in Spain) can cover up to about 20000 sq. deg. with range up to about 12.5m. Dedicated algorithms search for brightness changes of objects listed in GLADE to detect optical transients that might be connected with those galaxies. In the analysis related to G29048 we considered data collected by Pi of the Sky North telescope located in Spain, near Huelva, between August 17 and August 21, while the earlier data collected between August 10 and August 16 were used as a reference. The observations were performed in wide visible band, with IR-cut and UV-cut filters only, to achieve deepest detection limit. For each scan field 10 images with 10s exposure were taken and stacked for the analysis. On the night of 20170817 we surveyed area that overlaped partially with the initial bayesstar skymap for G298048. Unfortunatly, the dedicated scan procedure was interupted twice that night by the GCN alerts, resulting in the event coverage reduced to only about 29% probability, even after including other data collected that night. Coverage of about 51% was expected for uninterupted scan procedure, as obtained on the following nights. Data was searched for any type of transients connected with objects from GLADE catalogue. No significant transient candidate remained after all selection cuts. We acknowledge hospitality and support of the INTA El Arenosillo Test Centre in Mazagón near Huelva, Spain. Fields covered with the sky scan procedure on 20170817 ------------------------------------------------------ Pointing (RA[deg],Dec[deg]) gives the center of 20x20 deg^2 FOV. Field name Pointing S0120_10_10 ( 10.8, -0.2) S0000+50_35 ( 16.9, 57.1) S0200+50_10 ( 17.7, 39.5) S0120_10_35 ( 29.4, 18.1) S0200+50_35 ( 47.0, 57.1) S0000+90_35 ( 61.0, 77.4) S1600+50_35 (227.7, 40.7) S1600+10_10 (230.2, 0.1) S0000+90_10 (244.6, 76.8) S1600+10_35 (249.2, 18.0) S1600+50_10 (257.5, 58.5) S1840+10_10 (270.4, 0.0) S2000+50_10 (287.8, 39.5) S1840+10_35 (289.3, 18.0) S2120+10_10 (310.6, -0.1) S2000+50_35 (317.1, 56.9) S2299+50_10 (317.6, 39.5) S2120+10_35 (329.4, 18.1) S2240+10_10 (330.5, -0.1) S2299+50_35 (347.0, 57.3) S0000+50_10 (348.0, 39.4) S2240+10_35 (349.5, 18.2) Fields covered with other sky observations on 20170817 ------------------------------------------------------ GRB170817_35 ( 39.2, 79.9), GRB170817_10 (250.2, 73.4), GRB170818_35 (312.4, 10.7), S0000-10_35 ( 9.0, -1.9), R0000+30_10 ( 11.3, 39.0), S0200+50_10 ( 17.7, 39.4), S0326+70_10 ( 33.0, 58.8), S0326+70_10 ( 33.2, 58.8), S0200+50_35 ( 47.0, 57.1), S0326+70_35 ( 89.9, 75.9), S1440+10_10 (210.2, 0.3), S1440+10_35 (229.0, 18.2), S1630+30_10 (236.9, 20.1), S1630+30_35 (258.5, 38.0), S2000-10_10 (289.8,-19.8), S2000-10_35 (308.7, -1.7), S2120-10_10 (309.8,-19.7), S2200+50_10 (317.4, 39.4), S2120-10_35 (328.9, -1.8), S2240+10_10 (330.4, -0.2), R0000+30_35 (349.6, 21.0), S2200+50_35 (346.7, 57.2), S2240+10_35 (349.3, 18.2), S0000-10_10 (350.0,-19.8), This message can be cited.