Spectrum of Var C in M33 in its maximum light
ATel #5538; A. Valeev, S. Fabrika, O. Sholukhova (Special Astrophysical Observatory, Nizhnij Arkhyz)
on 3 Nov 2013; 01:49 UT
Credential Certification: Sergei Fabrika (fabrika@sao.ru)
Subjects: Optical, Nova, Star, Variables
Referred to by ATel #: 6711
The classical LBV star Var C in M33 has entered a luminous (or low excitation) state as it was described in ATels #5362, #5403. We have taken spectra of the star with the Russian BTA telescope using SCORPIO spectrograph. The spectra were obtained on 5 Oct 2013 with spectral resolution of 13Å (3800-7200 Å range), on 01 Nov and 02 Nov with resolution of 2.2Å (in 4100-5800 Å and 5800-7400 Å ranges respectively). In the spectra we find a forest of FeII emission lines, several [FeII] lines and strong hydrogen lines. We find very weak HeI absorption lines; the HeI 5876Å line in the spectrum is ~3 and ~4 times weaker than SiII 6371Å and 6347Å absorption lines (respectively). SiII 5041Å, 5056Å are also observed in absorption. At a higher resolution the hydrogen lines and majority of FeII lines show P Cyg profiles. The wind velocity measured in FeII and Hα P Cygs (from peak to peak) is 250 km/s. It is 280 km/s in Hβ. The hydrogen lines have narrow and broad components. In Hα the narrow component has FWHM = 110 km/s and the broad one has FWHM = 900 km/s (corrected for spectral resolution). Our photometry on 01 Nov gives B=15.9, V=15.7, Rc=15.5, Ic=15.3.