The Graha's Devata, Not a God per Sun Sign

The vara lords are the clean part. Sunday Sun, Monday Moon, Tuesday Mars, Wednesday Mercury, Thursday Jupiter, Friday Venus, Saturday Saturn. Remedial custom links the Sun with Surya, Mars with Hanuman or Skanda, Mercury with Vishnu, Jupiter with the guru principle and often with Dakshinamurthy, Venus with Lakshmi, and Saturn with Shani. Rahu is commonly linked with Durga and Ketu with Ganesha. These are practice-links. They are not a verse that says a Leo must worship one deity and a Virgo another. Leo is a sign. The Sun is a graha that may or may not sit in Leo in your chart.

If Saturn mahadasha is running, all 19 years of it, Saturday and Shani are the relevant door. If Venus is running, all 20 years, Friday and Lakshmi are the relevant door. A Sun-sign list would send a Capricorn Sun to Saturn even during a Jupiter mahadasha of 16 years, which ignores the clock. The lagna lord is the other candidate, because that planet carries the 1st house. For Cancer lagna the lord is the Moon, so Monday has a personal claim that a solar sign cannot see.

Jaimini method looks toward the 12th from the Karakamsa for the ishta devata. That calculation needs the atmakaraka and the Navamsa, which need an accurate birth time. It does not need the newspaper Sun sign. Until that calculation is done, the honest devotion is the weekday of the dasha lord. A shrine at home is a 9th-house act, dharma, and the 9th lord's condition shows how that part of life already stands. The deity does not replace the 9th lord.