V371 Per - A Thick-Disk, Short-Period F/1O Cepheid

TL;DR

This paper reports on V371 Per, a unique double-mode Cepheid with the shortest fundamental period among Galactic beat Cepheids, indicating it belongs to the Thick Disk or Halo and has unusual metallicity and period characteristics.

Contribution

It presents the discovery and analysis of V371 Per's unique properties, including its period ratio, metallicity, and Galactic location, highlighting its distinction from other Galactic beat Cepheids.

Findings

V371 Per has the shortest fundamental period among Galactic beat Cepheids.

It exhibits an unusually high period ratio of 0.731.

The star is likely part of the Thick Disk or Halo, not the Thin Disk.

Abstract

V371 Per was found to be a double-mode Cepheid with a fundamental mode period of 1.738 days, the shortest among Galactic beat Cepheids, and an unusually high period ratio of 0.731, while the other Galactic beat Cepheids have period ratios between 0.697 and 0.713. The latter suggests that the star has a metallicity [Fe/H] between -1 and -0.7. The derived distance from the Galactic Plane places it in the Thick Disk or the Halo, while all other Galactic beat Cepheids belong to the Thin Disk. There are indications from historical data that both the fundamental and first overtone periods have lengthened.