Your iMac does not have a Blu Ray drive, read or write, so no.
But would an external drive not work?
Yes, there is an add-on for Toast 9 that will let you burn Blu-Ray disks.Possibly, I think extra software would be required. Might well work with Toast...
And that has... what significance?
If you get an external Blu-ray burner, you may burn data, SD video, and full HD video to the Blu-ray disks with Toast or something comparable. You cannot watch HDCP movies or burn HDCP content, but any HD content that you burn will be playable in Blu-ray players.
If you get an external Blu-ray burner, you may burn data, SD video, and full HD video to the Blu-ray disks with Toast or something comparable.