eastbound on Interstate 90
- 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.
- South Dakota (Wikipedia)
South Dakota (/- dəˈkoʊtə/; Sioux: Dakȟóta itókaga, pronounced [daˈkˣota iˈtokaga]) is a U.S. state in the North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Dakota Sioux Native American tribe, which comprises a large portion of the population with nine reservations currently in the state and have historically dominated the territory. South Dakota is the seventeenth largest by area, but the 5th least populous, and the 5th least densely populated of the 50 United States. As the southern part of the former Dakota Territory, South Dakota became a state on November 2, 1889, simultaneously with North Dakota. They are the 39th and 40th states admitted to the union; President Benjamin Harrison shuffled the statehood papers before signing them so that no one could tell which became a state first. Pierre is the state capital, and Sioux Falls, with a population of about 192,200, is South Dakota’s largest city.
