TITLE: GCN CIRCULAR NUMBER: 18494 SUBJECT: LIGO/Virgo G194575: MASTER Optical Inspection DATE: 15/10/27 16:47:42 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V.M. Lipunov (Lomonosov Moscow State University, SAI MSU), E.S. Gorbovskoy (SAI Lomonosow MSU), R.Rebolo (IAC), N.Budnev (API Irkutsk State Uni), A.Tlatov (Kislovodsk Solar Station, Pulkovo), V.V.Yurkov (Blagoveschensk State Pedagogical University) and D. Buckley(SAAO) behalf MASTER-team. MASTER-Net of robotic telescope spent a great sky survey for research LVC trigger G194575. We have not received an automatic socket messages through GCN. Therefore, we were not able to immediately start automatically survey inside error box and began it in the manual mode at 2015-10-22 23:17:52 on the MASTER-Kislovodsk telescope, which at that time had suitable weather condition. In the subsequent time MASTER-II telescopes SAAO (South Africa), IAC (Tenerife), Tunka (Baykal), Blagoveschensk and Kislovodsk cover approximately 9000 sq. degree of sky due to very flat probability distributuion (which actually includes all the sky). The observations inside on the lobe nead 1 h RA were greatly complicated by the proximity of the moon. It was finally covered 87% of the lobe nead 1 h RA and 14% of full probability. The remaining 13% of 1h lobo are overexposed background light of the moon. 3 sigma upper limit in our survey ranged from 17 to 20 depending on the distance to the moon and weather conditions. The best limit, which is obtained in our survey shows a color on a coverage map: http://master.sai.msu.ru/static/G194575/limits2.png We found following transitents during this survey: 1) MASTER OT J194142.51-563815.7 discovery – dwarf nova outburst, Amplitude more then 4.9m. MASTER-SAAO auto-detection system discovered OT source at (RA, Dec) = 19h 41m 42.51s -56d 38m 15.7s on 2015-10-25.80803 UT. The OT unfiltered magnitude is m_OT=17.1 (the limit is 18.5m, 6 images), m_OT=17.4 on 2015-10-26 18:38:50.366UT(2 images). There is no minor planet at this place. We have reference image without OT on 2015-03-23.04023 UT with unfiltered magnitude limit 20.2m. There is no known optical source at this place (VIZIER database, POSS limit is 22m). There is only Allwise source with W1=17.109, W2=17.373, W3=12.745. So there is a dwarf nova outburst with Amplitude more then 4.9m. The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/194142.51-563815.7_1.png 2) MASTER OT J184709.24-495633.9 discovery – dwarf nova outburst with Amplitude more then 3.4m MASTER-SAAO auto-detection system discovered OT source at (RA, Dec) = 18h 47m 09.24s -49d 56m 33.9s on 2015-10-25.79044 UT. The OT unfiltered magnitude is 17.2m (limit is 18.3m, 4 images). There is no minor planet at this place. MASTER-SAAO reobserved it on 2015-10-26 18:06:20.857 , m_OT=17.7 (2 images). We have reference image without OT on 2015-02-17.102UT with unfiltered magnitude limit 19.4m. There is USNO B1 star with B2=20.83, R2=20.58. So there is classic dwarf nova outburst with amplitude more then 3.4m. The discovery and reference images are available at http://master.sai.msu.ru/static/OT/184709.24-495633.9.png 3) MASTER OT J020836.79-104018.8 discovery MASTER-IAC auto-detection system discovered OT source at (RA, Dec) = 02h 08m 36.79s -10d 40m 18.8s on 2015-10-23.07405 UT. The OT magnitude in I-band is 17.0m (limit 18.4m). The OT is seen in 3 images. There is no minor planet at this place. We have reference image without OT on 2015-10-21.07257 UT with unfiltered magnitude limit 21.1m. There is 2MASS and WISE source with J=14.873, H=14.243, K=13.851 http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=&-out.add=_r&-out.add=_RAJ%2C_DEJ&-sort=_r&-to=&-out.max=20&-meta.ucd=2&-meta.foot=1&-c=32.153291666667+-10.671888888889&-c.rs=5 The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/020836.79-104018.8.png 4). MASTER OT J060553.93+283325.6 discovery -dwarf nova outburst with Amplitude more then 3.9m MASTER-Tunka auto-detection system discovered OT source at (RA, Dec) = 06h 05m 53.93s +28d 33m 25.6s on 2015-10-25.75079 UT. The OT unfiltered (W=0.2B+0.8R, calibrated to USNO-B) magnitude is 15.5m (the limit is 18.0m). The OT is seen in 9 images. We have reference image without OT on 2013-12-01.66689 UT with unfiltered magnitude limit 18.9m. There is USNO-B1 star with B2=20.53,R2=19.10,I=17.9, no JHK, so this OT is dwarf nova outburst with Amplitude more then 3.9m. Spectral observations are required. The discovery and reference images are available at http://master.sai.msu.ru/static/OT/MASTEROTJ060553.93+283325.6.jpg 5). MASTER-IAC automaticaly found the QUEST optical transient reported by GCN Circ.18473 (Rabinovich et al.) inside the LIGO error region for trigger G194575. MASTER-IAC auto-detection system detected OT source at (RA, Dec) = 00h 11m 27.62s -06d 25m 38.0s on 2015-10-26.97009 UT with unfiltered magnitude m_OT= 17.0 m +-0.3 (W=0.2B+0.8R calibrated to USNO-B1). Photometry is not very good because proximity of the Moon. The OT is seen in 5 images. There is no minor planet at this place. We have reference image without OT on 2015-10-09.09056 UT with 19.9 unfiltered magnitude limit.