An Upagraha in Jyotish is a secondary planet which holds lesser but useful importance than the primary nine planets. Upagarahas are used to make predictions better and more precise.

 Unlike the primary planets, Upagrahas are not heavenly bodies like Sun, Moon, Mercury, Venus, Mars, Jupiter and Saturn or shadow planets (Chhaya Graha) like Rahu and Ketu. Upagrahas are purely mathematical calculations which are not based on any calculations of Rahshis (zodiacs) or Bhavas (houses). 

There are nine Upagrahas linked to the nine Grahas (planets) which are recognized by Jyotish rules. These are:

1. Kaala  --- Sun

2. Dhoom --- Moon

3. Parivesh --- Mars

4. Ardha Prahar --- Mercury

5. Yamkantaka --- Jupiter

6. Vyatipat --- Venus

7. Gulika --- Saturn

8. Indradhanush --- Rahu

9. Upaketu --- Ketu

 These nine upagrahas are categorised in two categories. The first category has Gulika, Ardha Prahar, Yamkantaka and Kaala. The second category consists of Dhoom, Vyatipat, Indradhanush and Upaketu.

These two categories of upagrahas are not enemical to each other and they are categorised on the basis of their method of calculation.

The Upagrahas in first category are calculated on basis of the points based on set time difference from the actual sunrise and sunset. Also, these points keep on changing with every day of the week. The second category Upagrahas are also based on set time intervals from actual sunrise and sunset but their base points always remain constant throughout the week.