STIS spectroscopy of newborn massive stars in SMC N81

2001/10/26 by Mohammad Heydari, M. Heydari-Malayeri, M. R. Rosa +3 · 3 citations
Medicine · Physics and Astronomy · #Astro and Planetary Science #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Galaxy #Hertzsprung–Russell diagram #Hubble space telescope #Luminosity #Medicine #O-type star #Physics #Population #Stars #Stellar classification #Stellar evolution #Stellar, planetary, and galactic studies #Wolf–Rayet star #astro-ph

paper · pdf · doi:10.1051/0004-6361:20011574

9 pages, 3 figures

arxiv created 2001/10/26 · openalex publication_date 2002/01/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

Using Hubble Space Telescope observations with STIS, we study the main exciting stars of N81, a high excitation compact H ii region in the Small Magellanic Cloud (SMC). These far UV observations are the first spectroscopic measurements of stars in such a region and reveal features characteristic of an O6–O8 stellar type. The astonishing weakness of their wind profiles and their sub-luminosity (up to ~2 mag fainter in MV than the corresponding dwarfs) make these stars a unique stellar population in the Magellanic Clouds. Our analysis suggests that they are probably in the Hertzsprung-Russell diagram locus of a particularly young class of massive stars, the so-called Vz luminosity class, as they are arriving at the zero age main sequence.

Citations

• The Space Telescope Imaging Spectrograph Design
• Ultracompact HII regions: the impact of newly formed massive stars on their environment
• On the formation of massive stars
• Star Formation in Molecular Clouds: Observation and Theory
• HST study of the LMC compact star-forming region N83B

Cited by

• Stellar populations associated with the LMC Papillon Nebula
• A dearth of young and bright massive stars in the Small Magellanic Cloud
• The stellar environment of SMC N81