The predominating Deity of the sun is another expansion of Nārāyaṇa, who is illuminating the entire universe. The Lord enters the hearts of all living entities as the Supersoul, and He gives them intelligence and fulfills their material desires. This is also confirmed in Bhagavad-gītā. Sarvasya cāhaṁ hṛdi sanniviṣṭaḥ. "I am sitting in everyone's heart." (BG 15.15)
As the Supersoul, the Lord enters the hearts of all living entities. As stated in Brahma-saṁhitā (BS 5.38), aṇḍāntara-stha-paramāṇu-cayāntara-stham: "He enters the universe and the atom as well." In the Ṛg Veda, the predominating Deity of the sun is worshiped by, this mantra: dhyeyaḥ sadā savitṛ-maṇḍala-madhya-varti nārāyaṇaḥ sarasijāsana-sanniviṣṭaḥ. Nārāyaṇa sits on His lotus flower within the sun. By reciting this mantra, every living entity should take shelter of Nārāyaṇa just as the sun rises. According to modern scientists, the material world rests on the sun's effulgence. Due to the sunshine, all planets are rotating and vegetables are growing. We also have information that the moonshine helps vegetables and herbs grow. Actually Nārāyaṇa within the sun is maintaining the entire universe; therefore Nārāyaṇa should be worshiped by the Gāyatrī mantra or the Ṛg mantra.