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 is a star that has exhausted most of its fuel. White dwarfs are one of the densest forms of matter, being 200,000 times as dense as the earth. They are formed from small to medium-sized stars. very few white dwarfs, formed from larger stars, have atmospheres that are rich in oxygen. These white dwarfs have burned the carbon they once contained and the oxygen in their atmosphere is what remains of their cores.