[en] The putative association between the 10_.^d8 classical Cepheid TW Nor and the open cluster Lyngå 6 has generated considerable debate in the literature. New JHK_s photometry in tandem with existing radial velocities for Lyngå 6 stars implies cluster membership for TW Nor and establishes the variable as a high-weight calibrator for classical Cepheid relations. Fundamental mean parameters determined for Lyngå 6 are: d = 1.91 ± 0.10 kpc, E(J – H) = 0.38 ± 0.02, and log τ = 7.9 ± 0.1. The Benedict et al./Turner Galactic VI_c Wesenheit function was revised using TW Nor's new parameters: W_VI,0 (– 3.37 ± 0.08)log P₀ – 2.48 ± 0.08. TW Nor/Lyngå 6 lie beyond the Sagittarius-Carina spiral arm and occupy the Centaurus arm, along with innumerable young Cepheids and clusters (e.g., VW Cen and VVV CL070).

[en] Deep near-IR images from the VISTA Variables in the Vía Láctea (VVV) Survey were used to search for RR Lyrae stars in the Southern Galactic plane. A sizable sample of 404 RR Lyrae of type ab stars was identified across a thin slice of the fourth Galactic quadrant (295° < ℓ < 350°, −2.°24 < b < −1.°05). The sample’s distance distribution exhibits a maximum density that occurs at the bulge tangent point, which implies that this primarily Oosterhoff type I population of RRab stars does not trace the bar delineated by their red clump counterparts. The bulge RR Lyrae population does not extend beyond ℓ  ∼ 340°, and the sample’s spatial distribution presents evidence of density enhancements and substructure that warrants further investigation. Indeed, the sample may be employed to evaluate Galactic evolution models, and is particularly lucrative since half of the discovered RR Lyrae are within reach of Gaia astrometric observations.