MAXI J1820+070: Swift/UVOT counterpart correction
J. A. Kennea and M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift Observatory
In ATEL #11403 the UVOT counterpart reported was incorrect, and was in fact an unrelated star near the XRT position. In the UVOT prompt white image we detect a bright source, which has considerable brightening over archival images of the field, at the following coordinates, RA/Dec(J2000) = 75.09138, 7.1853, which is equivalent to: RA(J2000) = 18h 20m 21.93s, Dec(J2000) = +07d 11m 07.1s This source lies 0.36 arc-seconds from the source ASASSN-18el (ATEL #11400), and is therefore the same source.

We note that the XRT position is 10.5 arc-seconds from the UVOT/ASASSN position, however, given the brightness of the XRT source, we believe it is the same object as MAXI J1820-070 and the associated ASASSN-18el.

We apologize any confusion.
ultra-violet,star