- Stellar classification (Wikipedia)
In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the rainbow of colors interspersed with spectral lines. Each line indicates a particular chemical element or molecule, with the line strength indicating the abundance of that element. The strengths of the different spectral lines vary mainly due to the temperature of the photosphere, although in some cases there are true abundance differences. The spectral class of a star is a short code primarily summarizing the ionization state, giving an objective measure of the photosphere’s temperature.
- Theodore Roethke (Wikipedia)
Theodore Huebner Roethke (/ˈrɛtki/ RET-kee; May 25, 1908 – August 1, 1963) was an American poet. He is regarded as one of the most accomplished and influential poets of his generation, having won the Pulitzer Prize for poetry in 1954 for his book The Waking, and the annual National Book Award for Poetry on two occasions: in 1959 for Words for the Wind, and posthumously in 1965 for The Far Field. His work was characterized by a willingness to engage deeply with a multifaceted introspection, and his style was overtly rhythmic, with a skilful use of natural imagery. Indeed, Roethke’s mastery of both free verse and fixed forms was complemented by an intense lyrical quality that drew “from the natural world in all its mystery and fierce beauty.