  We present reconstructed sunspot positions based on observations reported in
letters between Gottfried Kirch and other contemporary astronomers from AD 1680
to 1709, i.e. in the last decades of the Maunder Minimum. The letters were
compiled and edited by Herbst (2006). The letters (and observations) from Kirch
are mostly by Gottfried Kirch, but some also by his 2nd wife Maria M. Kirch
(married 1692) and their son Christfried Kirch (born 1694). Using excerpts from
the letters, some with drawings, we found some 35 sunspot groups (often for
several days in a row or with interruptions) by Kirch and/or his letter
partners (in three cases, only the month is given: 1704 Jan, Feb, 1707 Mar,
otherwise always the exact dates) - usually one group at a time. We also found
17 explicit spotless days, several of them new (previously without any known
observations). We could constrain the heliographic latitude by Bayesian
inference for 19 sunspot groups - five of them completely new (one group 1680
May 20-22 from Kirch and Ihle, one to two groups 1680 Jun 15-23 for Kirch, one
group 1684 May 6 from Ihle, and one group 1688 Dec 14-15 from Kirch), while the
others mostly agree (within 2sigma) with previously published values for those
dates by others. With these data, we then amend the butterfly diagram for the
Maunder Minimum. By comparison of our data with the sunspot group catalog in
Hoyt & Schatten (1998), we noticed a number of discrepancies, e.g. that dates
for British observers in the Maunder Minimum (Flamsteed, Caswell, Derham,
Stannyan, Gray, and Sharp) as listed in Hoyt & Schatten (1998) are their
original Julian dates, not converted to the Gregorian calendar (10-11 day
offset in Hoyt & Schatten). Most of these modifications also apply to the
modified sunspot group catalog in Vaquero et al. (2016). We also present two
aurorae observed by the Kirchs in 1707 and 1716.
