Two New Wolf-Rayet Stars and a Luminous Blue Variable Star in the Quintuplet (AFGL 2004) Near the Galactic Center

As part of an 1800 pc 2 survey of the Galactic center region in the lines of He I (2.058 μm), Brγ (2.166 μm), and the He II/C IV complex (3.09 μm), we have found two new Wolf-Rayet stars, a WN9 and a WC9, near the Galactic center. K -band spectra of both stars show broad helium emission lines, and the WC9 shows broad carbon emission lines. A third emission-line star in the region has a spectrum and luminosity similar to a luminous blue variable (LBV). The stars are within 2 pc, in projection, of the Quintuplet cluster (AFGL 2004) and are probably members of this cluster on the basis of their proximity and expected ages. All three stars are evolved descendants of massive main-sequence stars having M initial ≳ 50 M ☉ (WC9), ≳ 20 M ☉ (WN9), and ≳ 40 M ☉ (LBV candidate). The LBV candidate has a luminosity of L ≈ 10 6.3 L ☉ , comparable to that of η Carinae ( L = 10 6.5 L ☉ ), one of the most luminous stars in the local group of galaxies. A total of five emission-line stars are now known to reside in the Quintuplet, and they collectively produce N Lyc ≈ 10 49 photons s -1 . The new LBV candidate generates enough ionizing photons to account for the "Pistol" H II region (G0.15-0.05), while the nearby "Sickle" (G0.18-0.04) may be ionized by a population of O stars accompanying the five emission-line stars.