A search for open cluster Cepheids in the Galactic plane
  We analyse all potential combinations of Galactic Cepheids and open clusters
(OCs) in the most up-to-date catalogues available. Isochrone fitting and
proper-motion calcula- tion are applied to all potential OC{Cepheid
combinations. Five selection criteria are used to select possible OC Cepheids:
(i) the Cepheid of interest must be located within 60 arcmin of the OC's
centre; (ii) the Cepheid's proper motion is located within the 1 sigma
distribution of that of its host OC; (iii) the Cepheid is located in the
instability strip of its postulated host OC; (iv) the Cepheid and OC distance
moduli should differ by less than 1 mag; and (v) the Cepheid and OC ages (and,
where available, their metal- licities) should be comparable: {\Delta}log(t
yr^-1) < 0.3. Nineteen possible OC Cepheids are found based on our
near-infrared (NIR) analysis; eight additional OC{Cepheid associations may be
genuine pairs for which we lack NIR data. Six of the Cepheids analysed at NIR
wavelengths are new, high-probability OC Cepheids, since they lie on the
near-infrared (NIR) period (P){luminosity relation (PLR). These objects include
TY Sct and CN Sct in Dolidze 34, XX Sgr in Dolidze 52, CK Sct in NGC 6683, VY
Car in ASCC 61 and U Car in Feinstein 1. Two additional new OC Cepheids lack
NIR data: V0520 Cyg in NGC 6991 and CS Mon in Juchert 18. The NIR PLR for our
confirmed sample of OC Cepheids is M_J = (-3.12 +/- 0.29) log(P day^-1)-(2.17
+/- 0.29) mag, which is in good agreement with the best NIR PLR available for
all Galactic Cepheids.
