A mysterious object has been spotted that is 10 million times brighter than the sun. Scientists can't work out why it hasn't exploded

• Ultraluminous X-ray sources (ULX) are objects that shine ten million times brighter than the sun. 
• Scientists have said they are too bright to exist, as they break the so-called Eddington limit.
• A new study confirms the brightness of a ULX — leaving the mystery of how it exists unsolved. 

Scientists have been left baffled by a mysterious celestial object so bright that physics dictates it should have exploded.