The telescope has access to stars of magnitude 18. Can you see a double star in it, each component of which is magnitude 19?

By the definition of stellar magnitude, an n-th magnitude star is 100 ^ 1/5 ≈ 2.5 times brighter than an (n + 1) th magnitude star. Two stars of 19 magnitude are only 2 times brighter than one star of 19 magnitude. Consequently, such a binary is fainter than an 18th magnitude star, and is inaccessible to the telescope.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.