TITLE: GCN CIRCULAR NUMBER: 28691 SUBJECT: GRB 201017A: GROWTH-India optical upper limit DATE: 20/10/19 15:40:46 GMT FROM: Harsh Kumar at Indian Inst of Tech,Bombay H. Kumar (IITB), U. Stanzin(IAO), V. Bhalerao(IITB), G. C. Anupama(IIA), S. Barway(IIA), report on behalf of the GROWTH-India collaboration: We observed GRB 201017A reported by Fermi GBM Team (GCN #28665) and Swift-BAT (A. D'Ai et al., GCN #28666; also see:- V. Lipunov et al., GCN #28667; M.R. Goad et al., GCN #28671; L. P. Xin et al., GCN #28672; S. Poolakkil et al., GCN #28675; J.A. Kennea et al., GCN #28678; S. Belkin et al., GCN #28679) with 0.7m GROWTH-India telescope. The field was observed in the SDSS r’ filter starting at 2020-10-17T12:54:58.41 UT i.e. ~3.13 hrs after the event detection by Swift-BAT. We did not find any new source in the stacked image of 10*300 sec exposure, within an uncertainty region of 2.6 arcsec around RA (J2000): 02h 26m 28.82s, Dec (J2000): +66d 40' 43.6" (GCN 28671) up to r’ > 21.01 mag (5-sigma), calibrated against PanSTARRs PS1 data release, (Flewelling et al., 2018). Assuming a typical power-law decay, this upper limit is consistent with the r’=22.9 mag detection by Belkin et al (GCN # 28679). The GROWTH India Telescope (GIT) is a 70-cm telescope with a 0.7-degree field of view, set up by the Indian Institute of Astrophysics and the Indian Institute of Technology Bombay with support from the Indo-US Science and Technology Forum (IUSSTF) and the Science and Engineering Research Board (SERB) of the Department of Science and Technology (DST), Government of India (https://sites.google.com/view/growthindia/). It is located at the Indian Astronomical Observatory (Hanle), operated by the Indian Institute of Astrophysics (IIA).