Imac 24" early 2009 OS Sierra

[Parsuto]

Hello everyone, I UNIMAC 24 "early 2009 and I can not install the new OS Sierra, does not allow me even to download it from the Apple Store, but I have a friend with a Imac 27 of 2014 that downloaded OS Sierra and could borrow it.
But how do I install it on my iMac 24 "?
I need some special drivers?
thank you

 

[Luap]

List of Macs Compatible with MacOS Sierra 10.12
According to Apple, the official compatible hardware list of Macs capable of running Mac OS Sierra 10.12 is as follows:

• MacBook Pro (2010 and later)
• MacBook Air (2010 and later)
• Mac Mini (2010 and later)
• Mac Pro (2010 and later)
• MacBook (Late 2009 and later)
• iMac (Late 2009 and later)