TITLE: GCN CIRCULAR NUMBER: 27218 SUBJECT: GRB 200219A: Chandra rapid ToO upper limit DATE: 20/02/26 06:32:01 GMT FROM: Takanori Sakamoto at AGU T. Sakamoto (AGU), E. Troja (NASA/GSFC/ORAU), J. Norris (BSU), S. D. Barthelmy (GSFC), J. L. Racusin (GSFC), N. Kawai (Tokyo Tech), A. Fruchter (STScI), M. Im (SNU) A Chandra ToO observation of GRB 200219A (Lien et al., GCN Circ. 27125; Bissaldi et al., GCN Circ. 27137) started on February 23 16:32 UT (~4.4 days after the GRB trigger) for a total of 19.2 ksec. We do not detect an X-ray afterglow at the location of the enhanced XRT position (Osborne et al., GCN Circ. 27138). The calculated 3-sigma upper limit is 3.3e-4 c/s in the 0.35-8 keV band using aprates of the CIAO software package. Using the best fit spectral parameters of the XRT PC mode data, we estimated an 3-sigma unabsorbed flux upper limit of 5.0e-15 erg/cm2/s in the 0.35-8 keV band. We would like to thank the Chandra operation team for rapidly approving and making this observation.