The Sun tenants Aquarius and we have Kuttanelloor Pooram. When Sun moves over to Pisces, we have Arattupuzha Pooram and the Sun in Aries triggers Trichur Pooram ! So these Poorams are based on the positions of Sol and Luna, Prachanda Soorya Sprihaneeya Chandrama, and when Moon occupies Pubba Star !