Infrared Photometric Distance to WZ Hya

Volume 51 number 1 (2023)

Download this article (pdf)

Camdon Ritterby

Department of Physics and Astronomy, Washington State University, Pullman, WA 99164-2814; camdon.ritterby@wsu.edu

Michael L. Allen

Department of Physics and Astronomy, Washington State University, Pullman, WA 99164-2814; mlfa@wsu.edu (corresponding author)

Abstract

A distance to the RR Lyrae star WZ Hya was determined to test how well period-luminosity-metallicity (PLZ) relations agree with current parallax measurements from Gaia. We obtained 120 photometric observations in the B, V, ip, and zs filters from 16 February to 28 May 2022. Fluxes were extracted using six-aperture photometry methods. The period found for WZ Hya was 0.5377 ± 0.0005 day. Using the theoretical PLZ relations, a weighted average distance of 872 ± 47 parsecs was determined for the V, ip, and zs filters with a minimization technique. This distance is compared to the distances found using color excess values found in the literature, which distances were 942 ± 51 and 931 ± 50 parsecs, respectively. The Gaia Data Release 3 (DR3) parallax distance is 999 ± 16 parsecs. The distances determined using the PLZ relation are consistent with the parallax-determined value from Gaia within 1–2 standard deviations.