C. B. Markwardt (CRESST & NASA/GSFC), S. D. Barthelmy (NASA/GSFC),
on behalf of the Swift BAT Team, report:
As noted in GCN #6781, currently Swift is calibrating
its new gyroscope configuration for the roll axis.
In GCN Circ #6782, we quoted an error circle radius of 3 arcminutes
for the BAT position for GRB 070913. This radius was incorrect. The
correct value was distributed in the Notice (radius ~9.97 arcmin).
We apologize for this error and any inconvenience this may have caused.
In ground analysis, we have now applied the roll axis correction, and
the new best position is, RA, Dec 228.734, -24.290, which is:
RA(J2000) = 15h 14m 56s
Dec(J2000) = -24d 17' 23"
with an uncertainty of 3 arcmin radius, 90% containment, including
systematic uncertainty). This is a shift of 6.2 arcmin from the
position quoted in GCN Circ #6782.