Discovery of the spectroscopic binary nature of the classical Cepheids FN Aql and V1344 Aql

TL;DR

This study identifies FN Aql and V1344 Aql as spectroscopic binary systems through combined photometric and spectroscopic analysis, revealing their binary nature and pulsation period variations over decades.

Contribution

First detection of spectroscopic binary nature in these classical Cepheids using combined radial velocity and photometric data.

Findings

FN Aql and V1344 Aql are spectroscopic binaries.

Pulsation periods show slight changes over 50 years.

Period variations are linked to stellar evolution.

Abstract

We present the analysis of photometric and spectroscopic data of two classical Cepheids, FN Aquilae and V1344 Aquilae. Based on the joint treatment of the new and earlier radial velocity data, both Galactic Cepheids have been found to be a member in a spectroscopic binary system. To match the phases of the earlier radial velocity data correctly with the new ones, we also determined the temporal behaviour of the pulsation period of these Cepheids based on all available photometric data. The O-C graph covering about half century shows slight changes in the pulsation period due to stellar evolution for both Cepheids.