Those are amazing objects in their own right, and also rather rare (perhaps because they're so difficult to spot) : there's eight known white dwarfs in the hundred nearest star systems to our sun.

Indians already hold four of the top eight slots on the Forbes billionaire list, while Mexico's Carlos Slim has surpassed bill Gates to claim the No. 2 spot.

While most of us should aim for that sweet spot of seven to eight hours of sleep a night, a small minority might need substantially less or substantially more.