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.