In astrology, the point of the ecliptic or the sign of the zodiac that rises in the east at the time of a person’s birth or another event is called the ascendant. It is marked as “Asc” (Ascendant) or “Lag” (Lagna) in the zodiac chart. The ascendant is a very significant parameter in the horoscope.
The ascendant is marked in the sign determined by the time of birth. The ascendant moves through one sign in approximately two hours or 5 Ghatis (This varies according to the location of the place on the globe). On the first day of the month of Medam (Mesha), the Mesha sign will be present right from sunrise. As each day passes in the month of Mesha, the time of Mesha in the sun sign declines. Thus on the last day of Mesha month, there will be only a few minutes of Mesha left. The ascendant has huge significance in a horoscope. It acts as the starting point of calculating the houses. If the time and place of birth are wrong, then the horoscope will also be wrong.
- The method commonly used by astrologers is to calculate the ascendant using the sunrise and sunset time, Udayalparam and Asthamayalparam and the oblique ascension (Rasimanam) of each region.
- A more detailed method is to estimate the longitude and latitude of the place of birth and find ascendant using the table of ascendants.
- A more thorough method is to find ascendant using the mathematical, trigonometric formula using longitude and latitude.