Classical Cepheids are among the most useful Galactic and nearby extragalactic distance tracers because of their well-defined period–luminosity relations ( PLRs ) .
Open cluster ( OC ) Cepheids are important objects to independently calibrate these PLRs .
Based on Data Release 1 of the VISTA Variables in the Vía Láctea survey , we have discovered four new , faint and heavily reddened OC Cepheids , including the longest-period OC Cepheid known , ASAS J180342 - 2211.0 in Teutsch 14a .
The other OC–Cepheid pairs include NGC 6334 and V0470 Sco , Majaess 170 and ASAS J160125 - 5150.3 , and Teutsch 77 and BB Cen .
ASAS J180342 - 2211.0 , with a period of \log P = 1.623 [ days ] is important to constrain the slope of the PLR .
The currently most complete JHK _ { s } Galactic Cepheid PLRs are obtained based on a significantly increased sample of 31 OC Cepheids , with associated uncertainties that are improved by 40 per cent compared with previous determinations ( in the J band ) .
The NIR PLRs are in good agreement with previous PLRs determined based on other methods .