Children's books from the 80s about a professor who used his smoking pipe to teleport himself, a girl and a boy to other worlds?

Question

I can’t remember the name of these books, but they are old sci-fi children's books from the 80s about a professor who used his smoking pipe to teleport himself, a girl (I think his niece or grand daughter) and a boy through space to other worlds.

One story I remember was about them being teleported to a stadium in space that had three Suns.

Answer 1

This was the Professor Gamma series, written by the astronomer Sir Fred Hoyle and his son Geoffrey and published by Ladybird (in the UK, at least, and I recall them being quite British in a Professor Quatermass/Doctor Who style, so I think it's unlikely they were published elsewhere). The series of four books was:

• The Frozen Planet of Azuron

• The Planet of Death

• The Giants of Universal Park

• The Energy Pirate