Morphological characteristics of OB spectra and environments

Walborn, Nolan R.
Highlights of Spanish Astrophysics VI, Proceedings of the IX Scientific Meeting of the Spanish Astronomical Society (SEA), held in Madrid, September 13 - 17, 2010, Eds.: M. R. Zapatero Osorio, J. Gorgas, J. Maíz Apellániz, J. R. Pardo, and A. Gil de Paz., p. 25-35


Following a brief exposition of the morphological process, two examplesof its application in contemporary astronomy are presented. The firstcomprises a major digital, blue-violet spectral classification program on Galactic O stars, that has already revealed three special categories or new members thereof: the Ofc class with C~III λ 4650 emissioncomparable to N~III λ4640, the Of?p class of magnetic obliquerotators, and the ONn class of nitrogen-rich rapid rotators. All ofthese categories portend further understanding of massive stellar atmospheres and evolution. The second example concerns the structure of massive young clusters and nebulae as a function of age on timescales of the order of or less than 10 Myr, which has provided a new insight into the Antennae major-merger starburst.