TITLE: GCN CIRCULAR NUMBER: 21736 SUBJECT: LIGO/Virgo G299232/PGWB170825.55: MASTER OT J033744.97+723159.0 inside 25m isophota of the NGC1343 galaxy is reddening DATE: 17/08/28 19:22:37 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V.M.Lipunov, E. Gorbovskoy, V.G.Kornilov, N.Tyurina, V.Shumkov, D.Kuvshinov, P.Balanutsa, O.Gress, A.Kuznetsov, M.I.Panchenko, A.V.Krylov, I.Gorbunov Lomonosov Moscow State University, Sternberg Astronomical Institute R. Rebolo, M. Serra-Ricart, G. Israelian, N.Lodiu The Instituto de Astrofisica de Canarias V.Yurkov, Yu.Sergienko, A.Gabovich Blagoveschensk Educational State University, Blagoveschensk N.M. Budnev, O. Gress, K. Ivanov, S.Yazev Irkutsk State University A. Tlatov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory R.Podesta, C.Lopez, F.Podesta Observatorio Astronomico Felix Aguilar (OAFA) , National University of San Juan, Argentina H.Levato, C.Saffe Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE), San Juan, Argentina D.Buckley, S.Potter, M.Kotze, South African Astronomical Observatory MASTER OT J033744.97+723159.0 (lipunov, Gorbovskoy, Kornilov et al., GCN LVC GCN 21719, 21780) is cheked recently by MASTER-IAC (Tenerife, Spain). Our photometrical results are: Date Time JD Filter Mag A* Mag_cor 2017-08-27 22:46:16 2457993.4487963 B 18.12 1.41 16.71 2017-08-27 22:50:10 2457993.4515046 V 16.81 1.07 15.74 2017-08-27 22:50:10 2457993.4515046 R 16.04 0.80 15.24 2017-08-27 22:46:16 2457993.4487963 I 15.94 0.51 15.43 * for E(B-V) = 0.3436 and Av = 3.1 * E(B-V) = 1.065 =========================== Uncorrected magnitude: B = 18.1226 V = 16.8078 R = 16.0422 I = 15.9435 E(B-V) = 0.3436 (http://irsa.ipac.caltech.edu/applications/DUST/ ) Av = 3.1 * E(B-V) => Av = 1.06516 (http://www.astro.ncu.edu.tw/~wchen/Courses/ISM/11.Extinction.pdf page 17) => http://www.astro.ncu.edu.tw/~wchen/Courses/ISM/11.Extinction.pdf (page 22 ) So, MASTER OT J033744.97+723159.0 is reddening (cf, Im et al, LVC GCN 21723). The spectroscopic observations are requared. This message can be citted.