//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16855 SUBJECT: GRB 140930A/MAXI J2259+524: MAXI-GSC detection DATE: 14/09/30 17:27:16 GMT FROM: H. Negoro at Nihon U. H. Negoro (Nihon U.), S. Ueno, H. Tomida, S. Nakahira, M. Kimura, M. Ishikawa, Y. E. Nakagawa (JAXA), T. Mihara, M. Sugizaki, M. Morii, M. Serino, J. Sugimoto, T. Takagi, A. Yoshikawa, M. Matsuoka (RIKEN), N. Kawai, T. Yoshii, Y. Tachibana (Tokyo Tech), A. Yoshida, T. Sakamoto, Y. Kawakubo, H. Ohtsuki (AGU), H. Tsunemi, D. Uchida (Osaka U.), M. Nakajima, K. Fukushima, T. Onodera, K. Suzuki, T. Namba, M. Fujita, F. Honda (Nihon U.), Y. Ueda, M. Shidatsu, T. Kawamuro, T. Hori (Kyoto U.), Y. Tsuboi, A. Kawagoe (Chuo U.), M. Yamauchi, Y. Morooka (Miyazaki U.), K. Yamaoka (Nagoya U.) , report on behalf of the MAXI team: A bright uncatalogued X-ray transient source was detected with MAXI/GSC at UT 2014-09-30T14:26. Assuming that the source flux was constant over the transit, we obtain the source position at (R.A., Dec) = (344.875 deg, 52.428 deg) = (22 59 30, +52 25 40) (J2000), equivalently (l, b) = (106.186 deg, -6.766 deg), with a 90% C.L. statistical error of 0.40 deg and an additional systematic uncertainty of 0.1 deg (90% containment radius). The X-ray flux averaged over the scan was 136 +- 30 mCrab (4-10 keV, 1 sigma error). There was no significant excess flux in the previous transit at UT 2014-09-30T12:54. The nature of the source is quite unknown. Since the source is located near the Galactic plane (l ~ -6.8 deg), this event might be an X-ray burst from a low mass X-ray binary near the Galactic plane. We tentatively name the source GRB 140930A and MAXI J2259+524 (originally, MAXI J2256+527 in the MAXI ML. "New-transient: 115"). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16871 SUBJECT: GRB 140930A/MAXI J2259+524: MASTER optical observations DATE: 14/10/01 14:59:43 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs E. Gorbovskoy, V. Lipunov, M.Pruzhinskaya, V.Kornilov, D.Kuvshinov, N.Tyurina, N.Shatskiy, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D.Denisenko, Lomonosov Moscow State University, Sternberg Astronomical Institute, Moscow State University A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov, A. Gabovich Blagoveschensk Educational State University, Blagoveschensk K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University V.Krushinski, I.Zalozhnih, A. Popov Ural Federal University, Kourovka Hugo Levato and Carlos Saffe Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) Claudio Mallamaci, Carlos Lopez and Federico Podest Observatorio Astronomico Felix Aguilar (OAFA) Three MASTER system telescopes (MASTER-Net: http://observ.pereplet.ru) located in Blagoveshchensk, Tunka and Kislovodsk have observed GRB140630A (Negoro et. al GCN 16855). MASTER II robotic telescope located in Blagoveschensk was pointed to the GRB140930A 21 sec after notice time and 6331 sec after trigger time at 2014-09-30 16:12:34 UT in two polarizations. On our single and coadd images we not found credible optical transient within MAXI error-box (Negoro et. al GCN 16855). The 5-sigma upper limit on single (180 s) images has been about 18.1 mag. The 5-sigma upper limit on coadd of 13 image with total exposure 2340 s is about 19.5m MASTER II robotic telescope located in Kislovodsk was pointed to the GRB140930A 22 sec after notice time and 6332 sec after trigger time at 2014-09-30 16:12:35 UT in two polarizations. On our single and coadd images we not found credible optical transient within MAXI error-box. The 5-sigma upper limit on single (180 s) images has been about 18.5 mag. The 5-sigma upper limit on coadd of first 12 image with total exposure 2160 s is about 20.5m MASTER II robotic telescope located in Tunka was pointed to the GRB140930A 93 sec after notice time and 6415 sec after trigger time at 2014-09-30 16:13:58 UT in two polarizations. On our single and coadd images we not found credible optical transient within MAXI error-box. The 5-sigma upper limit on single (180 s) images has been about 17.9 mag. The 5-sigma upper limit on coadd of 13 image with total exposure 2340 s is about 20.0 m The upper limits received by MASTER are given in the table below: t_start | t-t_mid | exptime | filt | lim | site | coadd -------------+-------------+---------+------+------+------+------- 16:12:35.693 | 6485 sec | 180 | P | 18.5 | K | 1 16:12:35.693 | 6485 sec | 540 | P | 19.5 | K | 3 16:19:43.551 | 8075 sec | 2160 | C |~20.5 | K | 12 16:12:34.498 | 6484 sec | 180 | P | 18.1 | B | 1 17:20:44.913 | 12010 sec | 2520 | C | 19.5 | B | 14 16:13:58.211 | 6568 sec | 180 | P | 17.9 | T | 1 16:32:51.181 | 9877 sec | 2340 | C |~20.0 | T | 13 Our white (clear) band is well described by a parity 0.8R+0.2B (USNO B1). The MASTER-NET coverage map available here: http://master.sai.msu.ru/static/GRB/GRB140930A/GRB140930A_cm.png The MASTER image of MAXI error box with upper limit ~20m available here (10Mb): http://master.sai.msu.ru/static/GRB/GRB140930A/GRB140930A_img.jpeg The message may be cited.