BOSTON â President Obama signed an executive order on Monday requiring federal contractors to provide up to seven days of paid sick leave a year, even as he accused Republican congressional leaders of endangering the economy and Republican presidential candidates of undercutting American workers.OSTON â President Obama signed an executive order on Monday requiring federal contractors to provide up to seven days of paid sick leave a year, even as he accused Republican congressional leaders of endangering the economy and Republican presidential candidates of undercutting American workers.
A dwarf star is a star of relatively small size and low luminosity. 1  Most main sequence stars are dwarf stars. The term was originally coined in 1906 when the Danish astronomer Ejnar Hertzsprung noticed that the reddest starsâclassified as K and M in the Harvard scheme could be divided into two distinct groups.
A white dwarf, also called a degenerate dwarf, is a stellar remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to that of the Sun, and its volume is comparable to that of Earth.A white dwarf's faint luminosity comes from the emission of stored thermal energy. The nearest known white dwarf is Sirius B, at 8.6 light years, the smaller component of the Sirius binary star. white dwarf is very dense: its mass is comparable to that of the Sun, and its volume is comparable to that of Earth. A white dwarf's faint luminosity comes from the emission of stored thermal energy. The nearest known white dwarf is Sirius B, at 8.6 light years, the smaller component of the Sirius binary star.