Discovery of a New Dusty B[e] Star in the Small Magellanic Cloud

TL;DR

This paper reports the discovery of a new B[e] supergiant star in the Small Magellanic Cloud, identified through optical spectroscopy and infrared observations, revealing its circumstellar dust and gas characteristics.

Contribution

It presents the first identification of a B[e] supergiant in the SMC, expanding the known population of such stars in this galaxy.

Findings

Detection of Fe II, [O I], and [Fe II] emission lines.

Infrared excess indicating warm circumstellar dust.

Star likely a B-type supergiant.

Abstract

We present new optical spectroscopic and archival Spitzer IRAC photometric observations of a B-type star in the SMC cluster NGC 346, NGC 346:KWBBe 200. We detect numerous Fe II, [O I], and [Fe II] lines, as well as strong P-Cygni profile H I emission lines in its optical spectrum. The star's near-IR color and optical to IR SED clearly indicate the presence of an infrared excess, consistent with the presence of gas and warm, T ~800 K, circumstellar dust. Based on a crude estimate of the star's luminosity and the observed spectroscopic line profile morphologies, we find that the star is likely to be a B-type supergiant. We suggest that NGC 346:KWBBe 200 is a newly discovered B[e] supergiant star, and represents the fifth such object to be identified in the SMC.