SVOM/GWAC-F60 and GRANDMA optical follow-up of AT2018cow/ATLAS18qqn
ATel #11796; H. Li (NAOC), P. Zhang (NAOC), Y. Xiao (NAOC), R. Zhang (NAOC), S. Antier (LAL), S. Basa (LAM), M. Boer (Artemis), N. Christensen (Artemis), B. Cordier (CEA), M. Coughlin (Caltech), D. Coward (UWA), B. Gendre (UWA), X. Han (NAOC), N. Khantanakorn (Artemis), A. Klotz (IRAP), N. Leroy (LAL), E. Liang (Guangxi univ), X. Lu (NAOC), J. Mao (YNAO), Y. Qiu (NAOC), D. Turpin (NAOC), J. Wang (NAOC), X. Wang (Guangxi univ), J. Y. Wei (NAOC), C. Wu (NAOC), L. Xin (NAOC), Y. Xu (NAOC), W. Zheng (UC Berkeley) for the SVOM/GWAC and the GRANDMA teams
on 29 Jun 2018; 20:40 UT
Credential Certification: Sarah Antier (antier@lal.in2p3.fr)
Subjects: Optical, Gamma-Ray Burst, Supernovae, Transient
We observed the field of ATLAS18qqn/AT2018cow (Smartt et al. ATel #11727) consecutively in Bessel filters BVRI (100s exposure for each frame) with the GWAC/F60-A and GWAC/F60-B 60cm telescopes
at the Xinglong observatory. We have made observations of ATLAS2018qnn/AT2018cow during seven days from 2018-06-20 13:01:55 UT to 2018-06-27 18:33:12.902 UT. We detected the OT in all our frames with an optical flux consistent with the measurments of Zheng et al. (ATel#11743), Klotz et al. (ATel#11757), Wu et al. (Atel#11758), Basa et al. (ATel#11760)
and other photometric measurments: : Smartt et al. (Atel #11742, #11727), Fremling et al. (ATel #11738), Chen et al. (ATel #11734, #11729) and Im et al. (ATel #11772).
From T-T0 ~ 4-6.5 days the source has faded by ~0.17mag/day and then tends to fade at a much slower rate: ~0.04mag/day from ~6.5 to 11 days after T0. (T0 is the ATLAS2018qnn trigger time MJD 58285.441 == 2018-06-16 10:35:02 UTC). Note that the photometric results reported here are not corrected from the host galaxy.
Further observations are planned for the next nights at the Xinglong observatory with the GWAC-F60 telescopes.
