Ofcourse puranas are there. They came after upanishad and vedas. Most of sampradays has used them as authentic is not good! Some where said shani drushti and some where said trishul in Ganesh!! Even look at stories of Grahan!! But bhaskaracharya garg brahmgupt etc astronomers have calcutete this happen in astronomy their lots of book even newton nd other countries scientists also. Calculation come true today also!!Katha is used to create shradhdha. So all stories are not a history!! But the good idea to create Shradhdha.
