Toward Understanding The B[e] Phenomenon: III. Properties of the optical counterpart of IRAS 00470+6429

TL;DR

This study investigates the optical properties and variability of IRAS 00470+6429, a B[e] phenomenon star, revealing its likely binary nature, spectral features, and distance, contributing to understanding FS CMa type stars.

Contribution

It provides detailed spectroscopic and photometric analysis of IRAS 00470+6429, suggesting it is a binary system with specific spectral characteristics and variability patterns.

Findings

Optical spectrum dominated by emission lines with P Cyg profiles

Detected brightness variations and spectral line profile changes

Likely binary system with B2--B3 primary and late-type secondary

Abstract

FS CMa type stars are a group of Galactic objects with the B[e] phenomenon. They exhibit strong emission-line spectra and infrared excesses, which are most likely due to recently formed circumstellar dust. The group content and identification criteria were described in the first two papers of the series. In this paper we report our spectroscopic and photometric observations of the optical counterpart of IRAS 00470+6429 obtained in 2003--2008. The optical spectrum is dominated by emission lines, most of which have P Cyg type profiles. We detected significant brightness variations, which may include a regular component, and variable spectral line profiles in both shape and position. The presence of a weak Li {\sc I} 6708 \AA line in the spectrum suggests that the object is most likely a binary system with a B2--B3 spectral type primary companion of a luminosity $\log$ L/L$\odot$ = 3.9$\pm$0.3 and a late-type secondary companion. We estimate a distance toward the object to be 2.0$\pm$0.3 kpc from the Sun.