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GCN Circular 29113

GRB 201221D: Prompt enhanced Swift-XRT position
2020-12-21T23:32:42Z (3 years ago)
Phil Evans at U of Leicester <>
P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:

Using  promptly downlinked XRT event data for GRB 201221D, we find an
enhanced XRT position of the afterglow: RA, Dec: 171.0587, 42.1438
which is equivalent to:
   RA (J2000)  = 11 24 14.09
   Dec (J2000) = +42 08 37.5
with an uncertainty of 4.2 arcseconds (radius, 90% confidence).
Analysis of the promptly available data is online at

Position enhancement is is described by Goad et al. (2007, A&A, 476,
1401) and Evans et al. (2009, MNRAS, 397, 1177).

This circular is an official product of the Swift-XRT team.
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