TITLE: GCN CIRCULAR NUMBER: 26065 SUBJECT: GRB191024A: MASTER optical observation DATE: 19/10/24 10:03:29 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, F.Balakin,N.Tyurina,P.Balanutsa,A.Kuznetsov, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov,V.Senik, T.Pogrosheva, K.Pozdnyakov,A.Chasovnikov, V.Topolev, D.Kuvshinov(Lomonosov Moscow State University, SAI,Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile(Observatorio Astronomico FelixAguilar OAFA), H.Levato(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE), R. Rebolo, M. Serra(The Instituto de Astrofisica de Canarias), D. Buckley(South African Astronomical Observatory), O.A. Gres, N.M. Budnev, O.Ershova(Irkutsk State University, API), A. Tlatov, D. Dormidontov(Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich, Yu. Sergienko(Blagoveschensk Educational State University) MASTER-OAFA (MASTER Global Robotic Net http://observ.pereplet.ru, Lipunov et al.,2010,Advances in Astronomy, vol.2010, 30L) located in Argentina (OAFA observatory of San Juan National University) was pointed to the SWIFT GRB191024A (Page et al.GCN #26063, Beardmore et al. GCN 26064 trigger No 931242, XRT R.A.Dec(2000)=00h 40m 27.53s -67d 08' 42.2") errorbox 37 sec after trigger time at 2019-10-24 04:43:29 UT, with upper limit up to 14.4 on 10s images (18.2 mag on 1800s sum) There is no OT on first images. The observations began at zenith distance = 38 deg. The sun altitude was -47.1 deg. The galactic latitude b = -60 deg., longitude l = 98 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/event.php?id=1175693 We obtained the following upper limits: Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 42 | MASTER-OAFA | C | 10 | 14.4 | 83 | MASTER-OAFA | C | 10 | 13.8 | 131 | MASTER-OAFA | C | 20 | 14.5 | 187 | MASTER-OAFA | C | 30 | 14.6 | 237 | MASTER-OAFA | C | 130 | 15.3 | Coadd 253 | MASTER-OAFA | C | 40 | 14.3 | 335 | MASTER-OAFA | C | 60 | 14.9 | 436 | MASTER-OAFA | C | 80 | 15.6 | 546 | MASTER-OAFA | C | 300 | 16.1 | Coadd 558 | MASTER-OAFA | C | 100 | 15.2 | 700 | MASTER-OAFA | C | 120 | 15.4 | 866 | MASTER-OAFA | C | 150 | 16.3 | 1873 | MASTER-OAFA | C | 1800 | 17.7 | Coadd 6099 | MASTER-OAFA | C | 1800 | 18.2 | Coadd Reduction will be continued. The message may be cited.