GRB 180618A: MASTER OT observation (a short GRB with extended emission)
Abstract
MASTER-Kislovodsk robotic telescope (MASTER-Net: http://observ.pereplet.ru Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) , located in Kislovodsk Solar Station of Pulkovo observatory, was pointed to the Swift GRB180618A (LaPorte et al. GCN #22790; Sakamoto et al., GCN #22796) 25 sec after notice time and 41 sec after trigger time at 2018-06-18 00:43:53 UT. On our first (10s exposure) polarization set we haven`t found optical transient within SWIFT error-box (ra=169.933 dec=73.8478 r=0.05). The 5-sigma upper limit has been about 15.2 mag The observations made on zenit distance = 61 degrees, galaxy latitude b = 42 degree. The moon (24 % bright part) below the horizon (The altitude of the Moon is -31 degree ). Observations started at twilight and bad transparency. The sun altitude is -6.8 degree. MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in IAC was pointed to the GRB180618A 1734 sec after trigger time at 2018-06-18 01:12:07 UT. On our first (180s exposure) set we found ~19 mag optical transient within SWIFT UVOT error-box (LaPorte et al. GCN #22790; Guidorzi et al., GCN #22792;). The 5-sigma upper limit has been about 19.0 mag on single (180 s) and 20.5 on coadd (1800 s) exposures. ==================================================================== The observations made on zenit distance = 64 degrees, galaxy latitude b = 42 degree. The moon (24 % bright part) below the horizon (The altitude of the Moon is -15 degree ). The sun altitude is -38.3 degree. The object can be observed till sunrise at 2018-06-18 06:08:21 The message may be cited.
- Publication:
-
GRB Coordinates Network
- Pub Date:
- June 2018
- Bibcode:
- 2018GCN.22797....1T