15.05.10: A Speedy Binary.

 
  
  
   Think that new Ducati in your garage is fast? Let me introduce you to HM Cancri. An unassuming +21 magnitude binary in the constellation Cancer, HM Cancri is comprised of two white dwarfs locked in a tight embrace. In fact, this binary system has the shortest orbital period known, handily knocking down distant contender [...]