Spectroscopic analysis of two peculiar emission line stars: RJHA 49 and SS73 21

TL;DR

This study analyzes the spectra of two peculiar emission-line stars, RJHA 49 and SS73 21, revealing details about their physical conditions and suggesting their possible evolutionary stages, with new high-resolution data providing insights into mass loss and spectral features.

Contribution

First high-resolution spectral analysis of RJHA 49 and detailed spectral features of SS73 21, clarifying their physical conditions and evolutionary status.

Findings

SS73 21 shows active mass loss with P-Cygni profiles.

RJHA 49's nature is more likely B[e]-supergiant or proto-planetary nebula.

High-resolution spectra reveal double-peak Halpha in SS73 21.

Abstract

Aims: To investigate the spectra and the evolutionary stages of two peculiar emission-line stars: RJHA 49 and SS73 21. Methods: We used low and high resolution optical data. Line identifications and measurements were performed for several features in their spectra. Results: For each object, we have derived the extinction and the excitation temperature from a set of [Fe II] lines, and the electron density from [N II] lines. For RJHA 49, no detailed spectroscopic study was done so far. Regarding SS73 21, our low resolution spectrum have confirmed the main characteristics found in previous works. On the other side, from our high resolution data, we have found that the Halpha line presents a double-peak, in contrast with the suggestion in the literature that it should reveal a P-Cygni profile. Surprisingly, we found a few He I transitions resembling P-Cygni profiles (e.g. He I 5876), directly suggesting that mass loss is active in SS73 21. We also discussed the nature of these two objects based on the data obtained. Although the evolutionary status of SS73 21 seems well established from previous studies (a proto-planetary nebula), the situation for RJHA 49 is not so clear mainly due to its unknown distance. However, from the strength of [N II] 5754 relative to [O I] 6300, the possibility of RJHA 49 being a LBV object is reduced, and a B[e]-supergiant or a proto-planetary nebula status is more plausible.