AAVSO: American Association of Variable Star Observers

V350 Muscae: RR Lyrae Star Distance Estimate and RRab Reclassification

Volume 49 number 1 (2021)

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Demetris Nicolaides
Natural Science and Mathematics, Bloomfield College, 467 Franklin Street, Bloomfield, NJ 07003; demetris_nicolaides@bloomfield.edu
Destiny L. King
Bloomfield College, 467 Franklin Street, Bloomfield, NJ 07003
Sandra Moreno Cristobal
Gardner-Webb University, 110 S. Main Street, Boiling Springs, NC 28017

Abstract

V350 Mus was observed in the B, V, and, for the first time, the i and z bands, for a total of eighteen days. The telescope images were processed through aperture photometry. The star’s light curves reclassified it as an RRab type from its previous RRc or EW (eclipsing variable) classification. Its pulsation period was 0.3705 ± 0.0012 day. Three theoretical period-luminosity-metallicity relations of RR Lyrae stars (MV, Mi, and Mz), were shown to collectively work quite well with the corresponding observed apparent magnitudes of V350 Mus in matching its Gaia reported distance of (165.34 ± 1) parsecs. Specifically, the distance estimates (in parsecs) for the V, i, and z filters were 145.70 ± 11, 172.14 ± 7, and 176.70 ± 7, respectively, with their average being 164.85 ± 5, a mere 0.30% difference from the Gaia value. The calculation of the three-filter average distance was optimum when A, the extinction factor due to galactic reddening, was calibrated by implementing a simple new formula that considers the amount of each wavelength’s extinction proportionally, by balancing it with respect to the extinction of an average wavelength (instead of, say with respect to the extinction of only the V wavelength). The type of average wavelength that worked best was the weighted mean of the wavelengths that have a period-luminosity-metallicity relation (in our study, the V, i, and z wavelengths), and where the weight of a particular band wavelength was its ratio to an arbitrary reference wavelength.