References

 
• Baade, D. 1988, in O Stars and Wolf-Rayet Stars, ed. P. S. Conti, & A.B. Underhill, NASA SP-497, 137  
• Babel, J., & Montmerle, T. 1997, ApJ, 485, L29 NASA ADS  
• Berghöfer, T. W., Baade, D., Schmitt, J. H. M. M., et al. 1996, A&A, 306, 899 NASA ADS  
• Bieging, J. H., Abbott, D. C., & Churchwell, E. B. 1989, ApJ, 340, 518 NASA ADS  
• Chavarría-K., C., Jäger, C., & Leitherer, C. 1987, in Circumstellar Matter, ed. I. Appenzeller, & C. Jordan (Reidel, Dordrecht), Proc. IAU Symp., 122, 445  
• Christopoulou, P. E., Goudis, C. D., Meaburn, J., Dyson, J. E., & Clayton, C. A. 1995, A&A, 295, 509 NASA ADS  
• Conti, P. S. 1973, ApJ, 179, 181 NASA ADS  
• Conti, P. S., & Alschuler, W. R. 1971, ApJ, 170, 325 NASA ADS  
• Conti, P. S., & Leep, E. M. 1974, ApJ, 193, 113 NASA ADS  
• Conti, P. S., & Ebbets, D. 1977, ApJ, 213, 438 NASA ADS  
• Cranmer, S. R., & Owocki, S. P. 1996, ApJ, 462, 469 NASA ADS  
• de Jong, J. A., Henrichs, H. F., Schrijvers, C., et al. 1999, A&A, 345, 172 NASA ADS  
• Doroshenko, V. T. 1972, SvA, 16, 402 NASA ADS  
• Eversberg, T., Lépine, S., & Moffat, A. F. J. 1998, ApJ, 494, 799 NASA ADS  
• Fullerton, A. W. 1999, in Variable and Non-spherical Stellar Winds in Luminous Hot Stars, ed. B. Wolf, O. Stahl, & A. W. Fullerton, Lecture Notes in Physics, 523, 3  
• Fullerton, A. W., Gies, D. R., & Bolton, C. T. 1996, ApJS, 103, 475 NASA ADS  
• Fullerton, A. W., Massa, D. L., Prinja, R. K., Owocki, S. P., & Cranmer, S. R. 1997, A&A, 327, 699 NASA ADS  
• Gillet, D., Burnage, R., Kohler, D., et al. 1994, A&AS, 108, 181 NASA ADS  
• Harries, T. J., & Howarth, I. D. 1996, A&A, 310, 533 NASA ADS  
• Henrichs, H. F. 1991, in Rapid variability of OB stars: Nature and diagnostic value, ed. D. Baade, Proc. ESO Workshop 36, 199  
• Howarth, I. D., & Prinja, R. K. 1989, ApJS, 69, 527 NASA ADS  
• Howarth, I. D., Prinja, R. K., & Massa, D. 1995, ApJ, 452, L65 NASA ADS  
• Howarth, I. D., Siebert, K. W., Hussain, G. A. J., & Prinja, R. K. 1997, MNRAS, 284, 265 NASA ADS  
• Kaper, L., Henrichs, H. F., Fullerton, A. W., et al. 1997, A&A, 327, 281 NASA ADS  
• Kaper, L., Henrichs, H. F., Nichols, J. S., & Telting, J. H. 1999, A&A, 344, 231 NASA ADS  
• Kuan, P., & Kuhi, L. V. 1976, PASP, 88, 128 NASA ADS  
• Lamers, H. J. G. L. M., & Leitherer, C. 1993, ApJ, 412, 771 NASA ADS  
• Lépine, S. 2002, in Interacting Winds from Massive Stars, ed. A. F. J. Moffat, & N. St-Louis, ASP Conf. Ser., 260, 185  
• Moffat, A. F. J., & Michaud, G. 1981, ApJ, 251, 133 NASA ADS  
• Osaki, Y. 1999, in Variable and Non-spherical Stellar Winds in Luminous Hot Stars, ed. B. Wolf, O. Stahl, & A. W. Fullerton, Lecture Notes in Physics, 523, 329  
• Owocki, S. P. 1999, in Variable and Non-spherical Stellar Winds in Luminous Hot Stars, ed. B. Wolf, O. Stahl, & A. W. Fullerton, Lecture Notes in Physics, 523, 294  
• Penny, L. R. 1996, ApJ, 463, 737 NASA ADS  
• Petrenz, P., & Puls, J. 1996, A&A, 312, 195 NASA ADS  
• Rauw, G., Morrison, N. D., Vreux, J.-M., Gosset, E., & Mulliss, C. L. 2001, A&A, 366, 585 NASA ADS  
• Reid, A. H. N., & Howarth, I. D. 1996, A&A, 311, 616 NASA ADS  
• Underhill, A. B., Gilroy, K. K., & Hill, G. M. 1989, AJ, 98, 1063 NASA ADS  
• Walborn, N. R. 1973, AJ, 78, 1067 NASA ADS  
• Werner, K., & Rauch, T. 2001, in Eta Carinae and Other Mysterious Stars: The hidden opportunities of emission spectroscopy, ed. T. R. Gull, S. Johansson, & K. Davidson, ASP Conf. Ser., 242, 229