TITLE: GCN CIRCULAR NUMBER: 36009 SUBJECT: EP240331A: MASTER optical observations DATE: 24/04/01 22:05:20 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru> V.Lipunov, P.Balanutsa (Lomonosov MSU), D.Buckley (SAAO), O.Gress, N.Budnev (ISU),E.Gorbovskoy, Ya.Kechin, K.Zhirkov, A.Kuznetsov, D.Vlasenko, Yu.Tselik,N.Tiurina, I.Gorbunov, V.Vladimirov,D.Zimnukhov, V.Senik, A.Yudin,A.Chasovnikov, D.Cheryasov(Lomonosov MSU,SAI,PhysicsDepartment), A.Sosnovskij (Crimean Astrophysical Observatory, RAS), C.Francile. F. Podesta, R.Podesta (Observatorio Astronomico Felix Aguilar OAFA), R. Rebolo, M. Serra(The Instituto de Astrofisica de Canarias), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity) MASTER Global robotic net (http://observ.pereplet.ru Lipunov et al.,2010,Advances in Astronomy,2010,30L) started EP240331A ( Pan et al. ATel #16564, Center:169.414 -20.042 +-20';trigger 2024-03-31 22:07:17UT; Notice=1 Apr 2024 16:14 UT) at 2024-04-01 20:43:31 after MeerLICHT GCN 36007 (Groot et al.) MASTER-SAAO robotic telescope located in South African Astronomical Observatory was pointed to the EP-WXT Alert 240331.92 (11h 17m 39.36s , -20d 02m 31.2s, R=0.2) errorbox 81374 sec after trigger time at 2024-04-01 20:43:31 UT, with upper limit up to 19.0 mag. The observations began at zenith distance = 14 deg. The sun altitude is -51.1 deg. MASTER-Tavrida robotic telescope was pointed at 2024-04-01 20:47:05 UT, with upper limit up to 16.1 mag. The observations began at zenith distance = 64 deg. The sun altitude is -39.4 deg. MASTER-Kislovodsk robotic telescope was pointed at 2024-04-01 21:22:51 UT, with upper limit up to 19.7 mag. The observations began at zenith distance = 67 deg. The sun altitude is -42.1 deg. The galactic latitude b = 38 deg., longitude l = 276 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2412001 We obtain the following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 81405 | 2024-04-01 20:43:31 | MASTER-SAAO | (11h 14m 32.28s , -19d 56m 04.1s) | C | 60 | 18.9 | 81405 | 2024-04-01 20:43:31 | MASTER-SAAO | (11h 16m 31.77s , -20d 09m 11.5s) | C | 60 | 18.9 | 81485 | 2024-04-01 20:44:51 | MASTER-SAAO | (11h 14m 29.81s , -19d 54m 44.8s) | C | 60 | 18.8 | 81485 | 2024-04-01 20:44:51 | MASTER-SAAO | (11h 16m 29.29s , -20d 07m 52.1s) | C | 60 | 18.9 | 81564 | 2024-04-01 20:46:11 | MASTER-SAAO | (11h 14m 30.49s , -19d 55m 52.3s) | C | 60 | 18.8 | 81564 | 2024-04-01 20:46:11 | MASTER-SAAO | (11h 16m 30.01s , -20d 08m 59.1s) | C | 60 | 18.9 | 81724 | 2024-04-01 20:48:50 | MASTER-SAAO | (11h 14m 29.27s , -19d 55m 18.4s) | C | 60 | 18.8 | 81724 | 2024-04-01 20:48:50 | MASTER-SAAO | (11h 16m 28.80s , -20d 08m 25.5s) | C | 60 | 18.9 | 81864 | 2024-04-01 20:50:10 | MASTER-SAAO | (11h 14m 29.42s , -19d 54m 16.8s) | C | 180 | 18.9 | 81864 | 2024-04-01 20:50:10 | MASTER-SAAO | (11h 16m 28.95s , -20d 07m 23.8s) | C | 180 | 18.8 | 82064 | 2024-04-01 20:53:30 | MASTER-SAAO | (11h 14m 37.88s , -19d 55m 13.6s) | C | 180 | 18.9 | Observations and reduction will be continued View this GCN Circular online at https://gcn.nasa.gov/circulars/36009. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...