On the crucial cluster Andrews-Lindsay 1 and a 4% distance solution for its planetary nebula

Abstract

Andrews-Lindsay 1 is a pertinent open cluster because it may host the planetary nebula (PN) PHR 1315-6555, yet ambiguities linger concerning its fundamental parameters (>50% scatter). New multiband BV JHW_1−4 photometry for cluster and field stars, in concert with observations of recently discovered classical Cepheids, were used to constrain the reddening and velocity-distance profiles along the sightline. That analysis yielded the following parameters for the cluster: E(J − H) = 0.24 ± 0.03, d = 10.0 ± 0.4 kpc (d_JH = 9.9 ± 0.6 kpc, d_BV = 10.1 ± 0.5 kpc), and log τ = 8.90 ± 0.15. The steep velocity-distance gradient along 𝓁 ∼ 305° indicates that two remote objects sharing spatial and kinematic parameters (i.e., PHR 1315-6555 and Andrews-Lindsay 1) are associated, thus confirming claims that the PN is a cluster member. The new distance for PHR 1315-6555 is among the most precise established yet for a Galactic PN (σ/d = 4%).