Spectral Classification of Algol C

TL;DR

This paper clarifies the spectral type of Algol C as an F1 V star using spectral subtraction, resolving previous uncertainties and aligning with recent abundance studies.

Contribution

It introduces a spectral subtraction method to accurately classify Algol C, providing clearer spectral type determination.

Findings

Algol C is classified as an F1 V star.

Spectral subtraction effectively isolates Algol C's light.

Results align with recent abundance analyses.

Abstract

The spectral classification of Algol C, the third star in the Algol triple system, has long been a matter of some uncertainty. There is good reason to suspect that it should be a metallic-line A-type star, and one study in particular showed that this was so, but further studies have cast doubt on that assessment. We utilized a simple spectral subtraction method between spectra taken in and out of primary eclipse to reveal the light of Algol C in the absence of the light from the brightest star. Our resultant spectrum is well-matched to an F1 V spectroscopic standard and shows no evidence of metallic-line spectral anomalies. We note that this classification matches recent abundance determinations for this source.