It turned out that whatever she shad earlier spotted was not Mercury! Now Ira followed the professor's instructions and began to focus...Magic made everything so much easy, didn't it?
Ira then took out her wand from her robes and made a swishing movement and muttered "Lens Focalis" and tapped it on telescope. Then she peered through her eyepiece...trying to find Mercury. The sky looked much clearer now.