Details. as.character and is.character are generic: you can write methods to handle specific classes of objects, see InternalMethods. Further, for as.character the default method calls as.vector, so dispatch is first on methods for as.character and then for methods for as.vector.
But this is the number of stars we can see from the entire Earth and we should remember that one hemisphere of Earth is always in daylight, so really only about 2500 to 5000 stars are visible at night from any given point on Earth.
Quasars can shine with the brilliance of a trillion suns and astronomers can use this light to silhouette objects nearer Earth. Average galaxies, such as the sunâs home, the Milky Way, can contain 100 billion stars. A light year is the distance light travels in a year in space, about 6 trillion miles.