STIS spectroscopy of newborn massive stars in SMC N81

Abstract

Using Hubble Space Telescope observations with STIS, we study the main exciting stars of N81, a high excitation compact Hii 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 on the zero age main sequence.

9 pages, 3 figures

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• Database of Geneva stellar evolution tracks and isochrones for UBVRIJHKLL'M, HST-WFPC2, Geneva and Washington photometric systems
• Formation of massive stars by growing accretion rate
• HST observations of the LMC compact HII region N11A
• HST study of the LMC compact star forming region N83B
• Blue irregular variable stars in the Small Magellanic Cloud from EROS2 : Herbig Ae/Be or classical Be stars ?

Cited by in corpus (15)

• Toward Understanding Massive Star Formation
• VLT K-band spectroscopy of massive stars deeply embedded in IRAS sources with UCHII colours
• Puzzling wind properties of young massive stars in SMC-N81
• A Spitzer Space Telescope far-infrared spectral atlas of compact sources in the Magellanic Clouds. I. The Large Magellanic Cloud
• A Spitzer Space Telescope far-infrared spectral atlas of compact sources in the Magellanic Clouds. II. The Small Magellanic Cloud
• The VLT-FLAMES Tarantula Survey. XIII: On the nature of O Vz stars in 30 Doradus
• On the presence and absence of disks around O-type stars
• $K$-band integral field spectroscopy and optical spectroscopy of massive young stellar objects in the Small Magellanic Cloud
• A dearth of young and bright massive stars in the Small Magellanic Cloud
• An interesting candidate for isolated massive star formation in the Small Magellanic Cloud
• A very young component in the pre-eminent starburst region of the Small Magellanic Cloud
• Stellar populations associated with the LMC Papillon Nebula
• The stellar environment of SMC N81
• Low-excitation blobs in the Magellanic Clouds
• The LMC HII region N 214C and its peculiar nebular blob