A Galactic O2 If*/WN6 star possibly ejected from its birthplace in NGC3603

Abstract

In this work I report the discovery of a new Galactic O2 If*/WN6 star, a rare member of the extremely massive hydrogen core-burning group of stars that due its high intrinsic luminosity (close to the Eddington limit), possess an emission-line spectrum at the beginning of their main-sequence evolution, mimicking the spectral appearance of classical WR stars. The new star is named WR42e and is found in isolation at 2.7 arcmin (about 6 pc) from the core of the star-burst cluster NGC3603. From the computed E(B-V) color excess and observed visual magnitude it was possible to estimate its absolute visual magnitude as MV =-6.3 mag, which is a value similar to those obtained by other researchers for stars of similar spectral type both, in the Galaxy and in the Large Magellanic Cloud. Considering the derived absolute visual magnitude, we computed a bolometric stellar luminosity of about 3.2x106 Lsun. Finally, the mass of the new O2If*/WN6 star was estimated by comparing its observed magnitudes and colors with those of other probable NGC3603 cluster members, founding that the WR42e initial mass possibly exceeds 100 Msun.

Accepted for publication on MNRAS Letters

References in corpus (8)

• The R136 star cluster hosts several stars whose individual masses greatly exceed the accepted 150 Msun stellar mass limit
• A Spectroscopic Survey of WNL Stars in the LMC: General Properties and Binary Status
• On the role of the WNH phase in the evolution of very massive stars: Enabling the LBV instability with feedback
• The very massive binary NGC3603-A1
• Internal dynamics and membership of the NGC 3603 Young Cluster from microarcsecond astrometry
• New Galactic Wolf-Rayet stars, and candidates. An annex to The VIIth Catalogue of Galactic Wolf-Rayet Stars
• A first orbital solution for the very massive 30 Dor main-sequence WN6h+O binary R145
• The very massive X-ray bright binary system Wack 2134 (= WR 21a)

Cited by in corpus (12)

• Dynamical ejections of massive stars from young star clusters under diverse initial conditions
• Spatial distribution of Galactic Wolf-Rayet stars and implications for the global population
• The Massive Star-forming Regions Omnibus X-ray Catalog
• On the Origin of Mass Segregation in NGC 3603
• The Villafranca catalog of Galactic OB groups: I. Systems with O2-O3.5 stars
• Two massive stars possibly ejected from NGC 3603 via a three-body encounter
• SOAR optical and near-infrared spectroscopic survey of newly discovered massive stars in the periphery of Galactic Massive star clusters I - NGC3603
• Spectral classification of B stars: The empirical sequence using SDSS-IV/APOGEE near-IR data
• Massive stars in the giant molecular cloud G23.3-0.3 and W41
• Massive stars in the SDSS-IV/APOGEE SURVEY. I- OB stars
• An O2If* star found in isolation in the backyard of NGC 3603
• An O2If*/WN6 Star Catch in the Act in a Compact Hii region in the Starburst Cluster NGC 3603