  [Abridged] The central field of the Andromeda galaxy (M 31) has been
monitored, using the Chandra HRC-I detector (about 0.1-10 keV energy range)
from 2006 to 2012 with the main aim to detect X-rays from optical novae. We
present a systematic analysis of all X-ray sources found in the 41 nova
monitoring observations, along with 23 M 31 central field HRC-I observations
available from the Chandra data archive starting in December 1999. Based on
these observations, we studied the X-ray long-term variability of the source
population and especially of X-ray binaries in M 31. We created a catalogue of
sources, detected in the 64 available observations, which add up to a total
exposure of about 1 Ms. We present a point-source catalogue, containing 318
X-ray sources with detailed long-term variability information, 28 of which are
published for the first time. The spatial and temporal resolution of the
catalogue allows us to classify 115 X-ray binary candidates showing high X-ray
variability or even outbursts in addition to 14 globular cluster X-ray binary
candidates showing no significant variability. The analysis may suggest, that
outburst sources are less frequent in globular clusters than in the field of M
31. We detected 7 supernova remnants, one of which is a new candidate and in
addition resolved the first X-rays from a known radio supernova remnant.
Besides 33 known optical nova/X-ray source correlations, we also discovered one
previously unknown super-soft X-ray outburst and several new nova candidates.
The catalogue contains a large sample of detailed long-term X-ray light curves
in the M 31 central field, which helps to understand the X-ray population of
our neighbouring spiral galaxy M 31.
