Software upgrade from OSX El Capitan

Good day,

I have this model

Mac (24-inch, Early 2009)

Model Identifier: iMac9,1

Part Number: MB418xx/A, MB419xx/A

Newest compatible operating system: OS X El Capitan 10.11.6

Tech Specs: iMac (24-inch, Early 2009)

 I would like to upgrade to the latest software which I believe is High Sierra. Is that possible? Or to whatever the latest software runs on this model.

Thanks for feedback,

Kind Regards

CHWineLover