What is sidereal astrology?
If you are from the western hemisphere, or really any country besides India, you may be confused when I say the Sun is in Scorpio if you know it to be in Sagittarius (for example). Here is a little info on my methods and the calculations I use for this blog. Unclouded Eye is a sidereal astrology blog. Sidereal astrology uses different calculations than western astrology. It is in line with the calculations that scientists and astronomers use. For example, if you go to an astronomy website, or if you look at the night sky through a telescope, you will see the planets in the placements that sidereal astrology uses. Did you know that when western astrology says that Mars is entering Aries (for example), you could look through a telescope and see Mars against the backdrop of the Pisces constellation?
Sidereal, or Vedic astrology, originated thousands of years ago in ancient India. It is believed to be the oldest branch of astrology. Egypt had its own branch of astrology in ancient times, along with Babylon, and these systems were later filtered down through Greco-Roman society into a sort of hodge-podge of astrological beliefs, which eventually morphed into the system the western world uses today.
All forms of astrology track the movement of the planets and luminaries (the Sun and Moon) and how these transits affect life on earth for humans. The western astrological calendar begins every year on the vernal/spring equinox. Aries is the first sign in the zodiac, and so on the vernal equinox the Sun enters Aries, according to western astrology. This date can sometimes fluctuate by a day or two, but is typically right on March 20th/21st every year. The Sun then spends a month or so in each sign, and back on to Aries at the start of the next vernal equinox. This is what is meant by a tropical year -- the time it takes the Sun to come to the same point on the ecliptic of the celestial equator, which takes about 364-366 days on average.
Sidereal astrology considers the backdrop of the night sky to be a fixed field of stars. Instead of looking at the Sun to realign on the ecliptic, it waits for the Sun to come back around to the exact same spot on the fixed star backdrop. The start of a sidereal year occurs when the Sun is back in the exact same alignment against the backdrop of the constellation of Aries.
The gravitational tug of the Sun and moon cause the Earth's axis to shift ever so slightly each year. This ends up adding a small amount of time to the tropical year, which is only noticeable after many hundreds or thousands of years. Our equinox dates do not take this shift into consideration, but this small fraction adds about 0.0138 degrees to the amount that the tropical and sidereal years are "off" from one another each year. Since western astrology does not account for this degree shift, the calculations eventually started to lag. For instance, in western astrology, 0 degrees Aries will start on March 20th every year, whether 1581 or 2025. Using the sidereal system, the Sun was actually at the point of 0 degrees Aries on April 9th in 1581, and will be on April 15th in 2025.
This is not meant to discourage you from using western astrology. It is has become ingrained in our culture, and so has taken on a sort of archetypal role in our collective consciousness. The validity of both systems is highly subjective, and it is important to open our minds to all possibilities. My own experience has shown me the value of sidereal astrology, but I invite you to check both out and figure out your own path rather than subscribing to any sort of rigid belief about either.