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.
Brown dwarfs are substellar objects not massive enough to sustain hydrogen-1 fusion reactions in their cores, unlike main-sequence stars. They occupy the mass range between the heaviest gas giants and the lightest stars, with an upper limit around 75 to 80 Jupiter masses (MJ).he defining differences between a very-low-mass brown dwarf and a gas giant (~13 M J) are debated. One school of thought is based on formation; the other, on the physics of the interior.