Discovery of New, Dust-Poor B[e] Supergiants in the Small Magellanic Cloud

Abstract

We present the discovery of three new B[e] supergiants (sgB[e] stars) in the Small Magellanic Cloud (SMC). All three stars (R15, R38, and R48) were identified in the course of our Runaways and Isolated O Type Star Spectroscopic Survey of the SMC (RIOTS4). The stars show optical spectra that closely resemble those of previously known B[e] stars, presenting numerous low-ionization forbidden and permitted emission lines such as [Fe II] and Fe II. Furthermore, our stars have luminosities of log(L/L_sun) > 4, demonstrating that they are supergiants. However, we find lower infrared excesses and weaker forbidden emission lines than for previously identified B[e] supergiants. Thus our stars appear to either have less material in their circumstellar disks than other sgB[e] stars, or the circumstellar material has lower dust content. We suggest that these may constitute a new subclass of dust-poor sgB[e] stars.

7 pages, 6 figures, accepted to ApJ

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• The Optical Depth of H II Regions in the Magellanic Clouds
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Cited by in corpus (10)

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• The Runaways and Isolated O-Type Star Spectroscopic Survey of the SMC (RIOTS4)
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• Runaway OB Stars in the Small Magellanic Cloud: Dynamical Versus Supernova Ejections
• The circumstellar environment and evolutionary state of the supergiant B[e] star Wd1-9
• Identification of new Galactic symbiotic stars with SALT. I. Initial discoveries and other emission line objects
• Binarity at LOw Metallicity (BLOeM): a spectroscopic VLT monitoring survey of massive stars in the SMC
• Optical spectra of 5 new Be/X-ray Binaries in the Small Magellanic Cloud and the link of the supergiant B[e] star LHA 115-S 18 with an X-ray source
• Classical Oe Stars in the Field of the Small Magellanic Cloud
• The emission-line regions in the nucleus of NGC 1313 probed with GMOS-IFU: a supergiant/hypergiant candidate and a kinematically cold nucleus