Abstract
Observations of the optical spectrum of the Wolf-Rayet eclipsing binary HD 5980 in the Small Magellanic Cloud show how one component of this binary system unexpectedly underwent an eruption transforming its spectral type from a hot WN3 to a cooler and more luminous WN11 type. Radial velocity analysis of the preoutburst spectra indicates that both components of the binary are massive stars with emission lines in their spectra. The component that erupted is found to be the one in front of the system during the light curve phase zero. Differential analysis of the H Balmer and He ii Pickering emission line strengths indicates that the hydrogen content changes with the cooling of the spectrum. The maximum light of the eruption of HD 5980 had a duration of a few months, but the slow change from a WNE spectrum to WNL type took about 10 years. The similarity of the present spectrum of HD 5980 to the galactic WR binary system WR 12 is noticed.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
