Distance–RV plot in the direction of Puppis. The solid curve shows our theoretical model based on Galactic rotation, with the dashed curves used to indicate the 1σ propagation errors. Gray circles are classical Galactic Cepheids from Mel’nik et al. (2015) in the third quadrant with Galatic latitudes −2^° <  b <  2^°, while triangles are bright stars with available RVs from Gaia DR2 with 242.5^° <  l <  243.5^° and −1^° <  b <  1^°. Squares with error bars show the position of NGC 2452 and NGC 2453.