His 300 rays gives light to each of three Lok - Bhoor Lok, Bhuvar Lok, and Swar Lok; and his 100 rays gives light to Paataal Lok. All planets shine through his light only. Among his 1,000 rays, seven rays are chief rays - Sushumnaa, Harikesh, Vishwakarmaa, Soorya, Rashmi, Vishnu, and Sarvbandhu.

Soorya or Sun has 12 Kalaa (phases) - (1) Tapinee, (2) Taapinee, (3) Dhumraa, (4) Mareechi, (5) Jwaalinee, (6) Ruchi, (7) Sushumnaa, (8) Bhogadaa, (9) Vishwaa, (10) Bodhinee, (11) Dhaarinee, and (12) Kshamaa.
(Naarad Puraan, p 414)

Soorya Siddhaant
The first Hindoo treatise on astronomy (300 AD) by an unnamed author.

Soorya's Names

(1) Aaditya,  (2) Ark,  (3) Bhaanu,  (4) Bhaaskar,  (5) Divaakar,  (6) Mitra,  (7) Pooshaa,  (8) Soorya, 
(9) Suvarnretaa,   (10) Swayambhoo,   (11) Timiraash,  (12) Twashtaa, 

Who reads these 12 names daily, he gets Param Gati being free from sins and diseases. 

He has some other names also. Who remembers these names he is not to be scared from any disease.
Tapan,  Taapan,  Kartaa,  Hartaa,  Maheshwar,  Loksaakshee,  Trilokesh,  Vyomaadhip,  Divaakar,  Agnigarbh, Mahaavipra,  Khag,  Saptaashwavaahan,  Padmhast,  Tamobhedee,  Rigved,  Yajuhsaamag,  Kaalpriya,   Pundareek,  Moolsthaan, and  Bhaavit. 
[Padm Puraan, 1/25]

Soorya's 12 Names in Bhavishya Puraan, p 73

The Sun Deity
This Deity is not the Sun in the sky, but is the one from which the basic absolute the Fire element is created. Some contexts also refer to the visible Sun which symbolizes the subtle Sun.

A. Names of the Sun Deity - The Sun Deity has several Names. Twelve of them are names of the Aaditya. When performing Soorya Namaskaar (the solar bent posture) his following twelve Names are chanted : 1. Mitra, 2. Ravi, 3. Soorya, 4. Bhaanu, 5. Khag, 6. Pooshaa, 7. Hiranyagarbh, 8. Mareechi, 9. Aaditya, 10. Saavitree, 11. Ark and 12. Bhaaskar. The word Aaditya (आदित्‍य) is derived from Aadi (आदि) and Atya (अत्‍य). Aadi means from the beginning and Atya means till the present moment.

The table above "Soorya's Names in Bhavishya Puraan" gives the Names of the Sun Deity suitable for chanting in different months. If the name of the Sun Deity which matches the month is considered as 100%, then in comparison to the other names which are of only 95% importance for that month.

B. His Birth - There are several references about his birth as the son of Indra, the son of Mitra-Varun, the son of Som, the son of Indra-Som, the son of Indra-Vishnu, the son of Indra-Varun, the son of Agni and Dhaataa and that of Agniras.

C. Mission and special features - Priest of the deities, Creation of the universe, the life of all living beings is dependent on the sun as it gives both radiance and light. The Sun deity eliminates physical illnesses and endows longevity.

The chariot of the Sun deity has one wheel and seven horses. Serpents are the reins. The chariot flies through the sky without touching the ground. Its charioteer, Arun does not have legs. Despite this due to His sattva component the Sun deity is constantly able to travel through the entire sky, that is why poets have praised Him. When the chariot of the Sun deity approaches the earth the charioteer is seen first and only then the Sun deity. That is why the advent of dawn that is rise of Arun (arunoday) occurs before sunrise (suryoday) !

Ability and manifest energy - Ability : Creation 40%, sustenance 10% and dissolution 50%
The rotation of the Sun is akin to this. Its stage of "sustenance" of 12 noon lasts only for a short period. The stage of ‘creation’ preceding it and the stage of ‘dissolution’ following it lasts for a longer duration.

Manifest energy : 10%. Information on Soorya frequencies is given in ‘Science of Spirituality : Chapter 20 - Holy festivals, point - Gudee Padavaa’.

D. Science behind the idol - In the ancient times the image of the sun was represented by carving or drawing a round dish with rays of sunlight. It was during the reign of the Mouryas and the Shrungas that idols in a human form began to be used in ritualistic worship. Temples of the Sun deity were mostly constructed during the reign of the Gupta dynasty. One comes across these temples in Gvalior, Mandasaur, Indore, Multan, Konark, Kashmir, Khadayat (Gujarat), Patan, Gaya, Jhashi, Nashik, Aurangabad, etc.

E. Family - Consorts: According to the Rig Ved - Ushaa, Pratyooshaa, Sandhyaa and Chaayaa. According to the Matsya Puran - Raagyee, Savarnaa, Chaayaa and Suvarchaa

Sons : Nasatya, Dastra (Ashwinee Kumaar), Revant, Vaivasvat Manu (Deity of making an offering to ancestors (Shraaddh Dev), Yam, Yamunaa, Saavarni Manu, Shani, Tapatee, Vishti, Prabhat and Raivat.
Charioteer and elder brother : Arun
The one who carries a staff : Raja and Shrosh
Writer : Pingal
Guardian Deities of the entrance (Dwaarpaal) : Kalmash and various birds from creation
Aadityas : The twelve months of the year have one Aaditya each and they assist the sun in governing the cycle of Nature. (Aaditya is also a Name of the Sun deity.)

Deities in the retinue: "Mitra is a Vedic deity. Based on the quality of “governing the path of the sun”, in the Braahman holy text Mitra is associated with the day and Varun (deity of rain) with the night. In literature on rituals of five sacrifices (Yagyas) Mitra is referred to as the white and Varun as the black animal. This will illustrate how Mitra and Varun were considered as the Deities of the day and night respectively. The indistinct statement in the Vaidik texts which states that Mitra is the Sun deity is supported by the holy text, Avestya of the Zoroastrians.’ (1) The Sun seen on the earth is referred to as Mitra. Mitra acquires frequencies of radiance through a series of Suns beginning from the basic Sun Deity. All the satellites of the Sun acquire vital energy (Praan) or radiance (Tej) from the Sun Deity.

F. Spiritual practice of the Sun deity - Intolerable: First chant any Name of the Sun Deity and then the name of any superior deity which one has not chanted before, each for two minutes. The Gaayatree Mantra is also a form of worship of the Sun deity.

Synonyms of Soorya -
Aaditya,  Anshumaan,  Ark,  Aryamaa, 
Bhaanu,  Bhaaskar,  Bhag, 
Divaakar, 
Haritaashwa, 
Lolaark,
Maartand,  Matang,  Mihir, 
Pooshaa,  Prabhaakar, 
Rashmimaalee,  Rashmirathee (who rides on rays), Ravi, 
Sahastra-Rashmi (who has a thousand rays),  Savitaa,
Tripuraantak, 
Vibhaavasu,  Vivaswaan.