Steve Foxe 
Black Hole Bandits [PDF ebook] 

Mr Kazarian has a problem … his evil cousin, Kronkhold, is threatening to consume the galaxy with his new device, a black-hole generator. Mr K’s four favourite students are in the library researching Albert Einstein when they see Mr K heading out on his mission to stop Kronkhold. What better way to learn about black holes and Einstein’s theories than to ride along? Oh, and hopefully help save their home in the Milky Way. Bravely facing Kronkhold and his space-pirate flunkies, Mr K and the students get a little too up-close and personal with a black hole and must outwit the evil scientist to save the galaxy and themselves!