Using Period-Luminosity-Metallicity relations to Calculate Distance for the RR Lyrae Star, EZ Lyr

Abstract

Reliable methods to measure intergalactic distances are a valuable resource in the field of astronomy. Periodic variables stars, such as RR Lyraes, can be used as standard candles to determine the distance to the stellar structures where they are located. For this reason, many different student groups observed and analyzed RR Lyrae stars through a research course offered by Our Solar Siblings, and the focus of this particular study was the star EZ Lyr. Images of EZ Lyr were taken by Las Cumbres Observatory and processed using tools provided for the research course. Light curves were produced in B, V, sdss-i and sdss-z filters that were analyzed to determine the star’s period and luminosity. The period-luminosity-metallicity relations described in Caceres and Catelan (2008) were used to calculate the distance to EZ Lyr in each filter. The final distance measurement, 1406±32pc was slightly closer (~100 pc) compared to results from the GAIA satellite.