TITLE: GCN CIRCULAR NUMBER: 23126 SUBJECT: MASTER: OT detection during two Fermi GBM triggers (555263883 and 555263883) error boxes inspection in 22.5 mag SDSS galaxy direction DATE: 18/08/11 08:07:27 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, O. Gress, N.Tiurina, E. Gorbovskoy, V.Kornilov, A.Kuznetsov, V.Chazov, I. Gorbunov, D.Zimnukhov, D.Kuvshinov, P.Balanutsa, V.Vladimirov, D. Vlasenko Lomonosov Moscow State University,SAI R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias (IAC) D. Buckley, South African Astronomical Observatory (SAAO) A. Tlatov, V.Senik, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory R. Podesta, F. Podesta, C. Lopez, C.Francile Observatorio Astronomico Felix Aguilar (OAFA) H.Levato, Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) O. Gres, N.M.Budnev , Yu.Ishmuhametova Irkutsk State University (ISU) A. Gabovich, V. Yurkov, Yu. Sergienko Blagoveschensk Educational State University (BSPU) MASTER-SAAO robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in SAAO was starting survey on the FERMI GRB180810.28 error-box (ra=02 08 55 dec=-33 44 22 r=7.76) 50089 sec after notice time and 53011 sec after trigger time at 2018-08-10 21:24:17 UT. The 5-sigma upper limit on our first (60s exposure) set is about 19.7 mag The full information about this GRB180810.28 available here https://196.21.94.34//master2/grb.php?not=2018-08-10+07%3A29%3A28.642038&sat=FERMI&gcrd=%2832.2292d%2C-33.7394d%29&eb=7.76&trig=2018-08-10+06%3A40%3A46.74&n=GRB180810.28 The observations made on zenit distance = 73 degrees, galactic latitude b = -72 degree. The moon ( 0 % bright part) below the horizon (The altitude of the Moon is -72 degree ). The sun altitude is -65.7 degree. The object can be observed till sunrise at 2018-08-11 05:17:19 UT. The coverage map is available at: http://www.pereplet.ru/lipunov/images/MASTER_MAP_GRB180810.28.png MASTER OT J023059.78-172027.1 discovery - OT in far SDSS galaxy direction, discovered during Fermi 555576051 trigger inspection. MASTER-SAAO auto-detection system ( Lipunov et al., "MASTER Global Robotic Net", Advances in Astronomy, 2010, 30L )
discovered OT source at (RA, Dec) = 02h 30m 59.78s -17d 20m 27.1s on 2018-08-11.15934 UT
The OT unfiltered magnitude is 17.5m (mlim=19.7). The OT is seen in 4 images. There is no minor planet at this place. We have reference image with unfiltered mlim = 20.0 m. There is SDSS galaxy (The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy, 2012) with 0.25 arcsec offset (inside our error box ~0.7 arcsec with r_m = 22.5 mag . However, we can not exclude that the object in the SDSS is a star. In this case we have an optical transient is CV. This OT was found during Fermi trigger ( https://gcn.gsfc.nasa.gov/other/555576051.fermi ) inspection (GRBtime=2018-08-10 06:40:46.74UT), but it was presented in MASTER-OAFA images on 2018-08-08 07:33:12 with m_OT=18.5 (also detected during Fermi inspection, but trigger number is 555263883 https://gcn.gsfc.nasa.gov/other/555263883.fermi )
Spectral observations are required. The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/023059.78-172027.1.png Finally, we just received a telegram from MASTER OAFA (Argentina): MASTER-OAFA robotic telescope (MASTER-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 GRB180810.28 1 days 1589 sec after notice time and 1 days 1589 sec after trigger time at 2018-08-11 07:07:16 UT. On our first (180s exposure) set we found 1 optical transient within Master error-box (ra=37.7458 dec=-17.3406 r=0.1) brighter then 18.83. T-Tmid Date Time Expt. Ra Dec Mag ---------|---------------------|-------|-----------------|-----------------|------- 1679 2018-08-11 07:07:16 180 ( 2h 30m 59.7s , -17d 20m 26.7s) 18.06 The 5-sigma upper limit has been about 18.83mag The message may be cited. ==================================================================== The observations made on zenit distance = 39 degrees, galactic latitude b = -64 deg. The moon ( 0 % bright part) below the horizon (The altitude of the Moon is -53 deg ). The sun altitude is -53.0 degree. The object can be observed till sunrise at 2018-08-11 11:17:13. This message may be cited.