@misc{GvaramadzeKniazevMiroshnichenkoetal.2012,
  author    = {Gvaramadze, V. V. and Kniazev, A. Y. and Miroshnichenko, A. S. and Berdnikov, Leonid N. and Langer, N. and Stringfellow, G. S. and Todt, Helge Tobias and Hamann, Wolf-Rainer and Grebel, E. K. and Buckley, D. and Crause, L. and Crawford, S. and Gulbis, A. and Hettlage, C. and Hooper, E. and Husser, T. -O. and Kotze, P. and Loaring, N. and Nordsieck, K. H. and O'Donoghue, D. and Pickering, T. and Potter, S. and Colmenero, E. Romero and Vaisanen, P. and Williams, T. and Wolf, M. and Reichart, D. E. and Ivarsen, K. M. and Haislip, J. B. and Nysewander, M. C. and LaCluyze, A. P.},
  title     = {Discovery of two new Galactic candidate luminous blue variables with Wide-field Infrared Survey Explorer},
  series = {Monthly notices of the Royal Astronomical Society},
  volume    = {421},
  journal   = {Monthly notices of the Royal Astronomical Society},
  number    = {4},
  publisher = {Oxford Univ. Press},
  address   = {Oxford},
  issn      = {0035-8711},
  doi       = {10.1111/j.1365-2966.2012.20556.x},
  pages     = {3325 -- 3337},
  year      = {2012},
  abstract  = {We report the discovery of two new Galactic candidate luminous blue variable (LBV) stars via detection of circular shells (typical of confirmed and candidate LBVs) and follow-up spectroscopy of their central stars. The shells were detected at 22 mu m in the archival data of the Mid-Infrared All Sky Survey carried out with the Wide-field Infrared Survey Explorer (WISE). Follow-up optical spectroscopy of the central stars of the shells conducted with the renewed Southern African Large Telescope (SALT) showed that their spectra are very similar to those of the well-known LBVs P Cygni and AG Car, and the recently discovered candidate LBV MN112, which implies the LBV classification for these stars as well. The LBV classification of both stars is supported by detection of their significant photometric variability: one of them brightened in the R and I bands by 0.68 +/- 0.10 and 0.61 +/- 0.04 mag, respectively, during the last 1318 years, while the second one (known as Hen 3-1383) varies its B, V, R, I and Ks brightnesses by similar or equal to 0.50.9 mag on time-scales from 10 d to decades. We also found significant changes in the spectrum of Hen 3-1383 on a time-scale of similar or equal to 3 months, which provides additional support for the LBV classification of this star. Further spectrophotometric monitoring of both stars is required to firmly prove their LBV status. We discuss a connection between the location of massive stars in the field and their fast rotation, and suggest that the LBV activity of the newly discovered candidate LBVs might be directly related to their possible runaway status.},
  language  = {en}
}
@article{GvaramadzeKniazevHamannetal.2010,
  author    = {Gvaramadze, Vasily V. and Kniazev, Alexei Y. and Hamann, Wolf-Rainer and Berdnikov, Leonid N. and Fabrika, Sergei Nikolaevich and Valeev, Azamat F.},
  title     = {A new Wolf-Rayet star and its circumstellar nebula in Aquila},
  issn      = {0035-8711},
  doi       = {10.1111/j.1365-2966.2009.16126.x},
  year      = {2010},
  abstract  = {We report the discovery of a new Wolf-Rayet star in Aquila via detection of its circumstellar nebula (reminiscent of ring nebulae associated with late WN stars) using the Spitzer Space Telescope archival data. Our spectroscopic follow-up of the central point source associated with the nebula showed that it is a WN7h star (we named it WR121b). We analysed the spectrum of WR 121b by using the Potsdam Wolf-Rayet model atmospheres, obtaining a stellar temperature of similar or equal to 50 kK. The stellar wind composition is dominated by helium with similar to 20 per cent of hydrogen. The stellar spectrum is highly reddened [E(B - V) = 2.85 mag]. Adopting an absolute magnitude of M-v = 5.7, the star has a luminosity of log L/L-circle dot = 5.75 and a mass-loss rate of 10(-4.7)M(circle dot)yr(-1), and resides at a distance of 6.3 kpc. We searched for a possible parent cluster of WR 121b and found that this star is located at similar or equal to 1 degrees from the young star cluster embedded in the giant HII region W43 (containing a WN7+a/OB? star - WR121a). We also discovered a bow shock around the O9.5III star ALS 9956, located at similar or equal to 0 degrees.5 from the cluster. We discuss the possibility that WR121b and ALS 9956 are runaway stars ejected from the cluster in W43.},
  language  = {en}
}