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.
1 There is a maximum of 2,500 stars visible to the naked eye at any one time in the night sky. 2  The nearest star to our solar system is Proxima Centauri which is 4.2 light years away.  The Sun is part of a single star system but there are also binary and multiple stars where two or more stars orbit around each other.