True Sidereal Astrology – Using the Actual Constellations in the Sky

True Sidereal Astrology is the only astrological system using the actual constellations in the sky, as they exist today, with each sign adjusted to match the actual degrees each constellation takes up on the ecliptic. This article will explain what is True Sidereal Astrology and its benefits when compared with other astrological systems like Tropical (Babylonian) and even Sidereal (Vedic).

Since the dawn of the human experience, we have looked to nature for guidance. Just as we looked around us on Earth, we also looked to the stars. We noticed patterns, felt subtle energies, and drew conclusions based on heart-brain-gut intuition and reasoning. This led to creating the original astrology.

Over time, our connection to nature became…more complicated. We started creating civilization, industry, and more advanced ways of existing and living on Earth. The systems we designed started becoming out of perfect alignment with nature, and we began creating new systems to make sense of the preceding systems we designed and applied to our lives. Two of these became known as Babylonian, or Tropical Astrology, and Vedic, or Sidereal Astrology (although Vedic has been more finetuned thanks to its highly-advanced Nakshatra system).

Note: We will focus on comparing Babylonian/Tropical/Western Astrology with True Sidereal Astrology due to Vedic/Sidereal, when combined with nakshatras and the right sizes of constellations, is almost identical to True Sidereal Astrology in most ways.

Almost everything online and in the West uses a system called tropical astrology. Most people aren’t aware that tropical astrology does not use the visible sky. Instead, it uses the seasons, which furthermore changes its meaning and significance depending on where you reside on the planet.

What Is the Zodiac

Before we dive into what is a bit of a polarizing topic, let’s start at the basics by answering the question of what is the Zodiac.

The Zodiac, also known as the Zodiacal belt, is the background and energy cycle behind the ecliptic plane in our solar system. The Zodiac, which is the outermost ring in your natal chart, is made up of the well-known Zodiac signs, such as Aries, Taurus, and Gemini to name a few.

What’s the ecliptic and it’s relation with the Zodiac?

Well, the orbits of the celestial bodies around the Sun follow this course. It’s been considered to be an electromagnetic field of energy that held the physical cosmic forms in orbit, including asteroids, planets, and other entities.

The Zodiac is located behind this ecliptic plane and varies based on the method used to determine it. The astrological cycle gives each element of your chart, from Aries to Pisces, a unique expression related to the sign of the zodiac that it corresponds with.

The Tropical Zodiac

The Tropical Zodiac is, without a doubt, the most widely recognized Zodiac system. This is the method and dates that we are all familiar with, and it is currently used by most American astrologers. Born in the period from March 21 to April 19? This system indicates that you are an Aries sun sign, for example.

The 12 Zodiac signs that make up the Tropical Zodiac each receive an equal 30º slice of the 360º Zodiac wheel. The Sun travels through each of the 12 signs for approximately one month during our yearly orbit around the Sun. The seasons on Earth, not the constellations, are used to calculate this system. This is the key difference between Tropical Astrology and others.

The first day of spring, also known as the Spring Equinox, corresponds to 12 equal hours of day and night, and is always represented by 1º Aries in the Tropical Zodiac. This means that Aries season begins on the first day of spring every year in the northern hemisphere.

1º Cancer is marked by the Summer Solstice, which is the longest day of the year and the first day of summer. Summer officially begins with Cancer season in the northern hemisphere.

The Autumn Equinox, when we have 12 equal hours of day and night, is usually observed as 1º Libra, thereby marking the start of the fall season in the northern hemisphere.

The longest night of the year, the Winter Solstice, falls on 1º Capricorn on the first day of winter. Capricorn welcomes the colder months (this is applicable in the Northern Hemisphere only). After that, the cycle repeats itself, with Aries rising once more on the next Spring Equinox. It is a constant, consistent system that never changes.

The tilt of the Earth’s axis with respect to the ecliptic plane, generates the cycle of time that is known as the Tropical Zodiac. We experience periods of longer days and longer nights every year due to the fact that our axis isn’t parallel with this plane; the equinoxes and solstices signify the transitions between the seasons. In fact, our axis, for reasons still unknown to us (most likely a massive impact in Earth’s ancient history), has a tilt of around 23.5º.

Most people are unaware that the Sun is not actually placed in the constellations—rather, it is not in Aries, Gemini, or Scorpio as the Tropical Zodiac suggests. The Tropical Zodiac isn’t really based on constellations as we currently recognize them in the sky. You are entering the realm of the Sidereal and True Sidereal Zodiac as soon as you begin to wonder where the Sun and other celestial bodies were in the sky at any given time, according to their constellation.

Tropical Astrology’s Babylonian Origins

While modern-day astrology has its roots in pre-historic astrological systems, it was significantly modified from its progenitors.

Around 2,000 years ago, all of the constellations that were seen in the sky matched up with the seasons experienced on Earth. At the time, the Sun was within the Aries constellation, which was also the first sign of the Zodiac, during the Spring Equinox. Fast-forward to today, and the Sun is actually in Pisces, not Aries, during the Spring Equinox.

What we know as Tropical Astrology, or Western Astrology is actually Babylonian Astrology, which was also greatly influenced by Ptolemy, who famously reinforced the geocentric idea that the Earth is the center of the universe and the Sun revolves around it. It was Ptolemy who convinced astrologers around 200 AD to make a more fixed and standardized system that bypasses the Precession of the Equinoxes, where the sun moves 1 degree every 72 years (resulting in certain signs today having deviated 1-3 signs from what they are said to be in Tropical and Sidereal).

Ptolemy, an astronomer from ancient Babylon, established the Tropical Zodiac as the accepted method two millennia ago since it was more helpful to the agrarian Babylonian Empire at the time to follow the seasons for agricultural purposes.

Rather than relying solely on our constantly changing alignment with the constellations, life was easier when there was a stable system based on the seasons and paired nicely with the months of the year in the calendar that was created (12 equal signs, each claiming one month of the year in terms of our orbit around the Sun).

While there is speculation regarding the astrological system Ptolemy advanced was meant to convince people of the time to adopt a larger conspiracy intended to pull humanity out of alignment with the balance of nature, for now we will focus only on the facts which we know to be true today.

Removal of Ophiuchus – the 13th Sign

One way True Sidereal Astrology differs from Tropical Astrology is that it acknowledges Ophiuchus, a 13th constellation that passes through the ecliptic, as being a sun sign, which was removed from the ancient Zodiac during the Babylonian revision of astrology.

This removal was done to make math (division) easier using 12 signs vs 13. The change led to the zodiac being divided into 12 equal segments of 30 degrees each, which does not reflect how the constellations in the ecliptic actually exist.

Overlapping Signs

Not only are there 13 constellations within the ecliptic, but many of them overlap one another and differ in size. This results in people born during certain times of the year being a blend of two signs. It also means dividing the zodiac into 12 neat sections that are 30º each is not reflective of how the signs actually exist. That would be nice, and make things easier, but it’s simply not how things actually work in reality.

Since each constellation takes up a different amount of the night sky, larger constellations like Virgo take up over 45º while smaller ones like Cancer span less than 20º.

This means the evenly-distributed pie that the simplified and standardized Tropical and Sidereal systems (although Sidereal’s nakshatras break signs down to such a degree that they end up sharing details that are very accurate) employs, does not reflect how the constellations actually appear.

The only astronomically based calendar that truly depicts the constellations and our alignment with them as they exist today is the True Sidereal Zodiac.

Note: Since many signs overlap with others in the actual sky. Therefore, anything within 3 degrees/days of another sign should be considered to be a blend of both signs, meaning it would display characteristics of both.

While the Tropical system had been likely designed to be more closely tied to the changes in seasons due to being developed by an agrarian society, True Sidereal exists as a model of a more universal approach when determining how celestial bodies actually affect human consciousness.

Vedic Astrology Nakshatra System
Vedic Astrology Nakshatra System

Let’s take a look at an example. Mainstream astrology might say someone’s Sun is in Leo, while the Sun is actually in Cancer. True Sidereal Astrology maintains the link between ourselves and the sky, by using the stars as they truly are. To put it another way, a Tropical Astrology chart (and to a lesser extent Vedic/Sidereal) is a man-made chart while True Sidereal Astrology is nature, charted.

Thanks to technology via free open-source software like Stellarium, we can now see the visible sky in astrological chart form. With the internet, true sidereal astrology is gaining widespread adoption. A growing number of people now believe this is the most accurate form of astrology because it uses what is actually in the sky…a system we have been using far longer than the past 2000 years. As seen at ancient megalithic sights like Gobekli Tepe and others, the people of that time appeared to follow the celestial patterns they observed in the night sky, which they then recorded in the stones at powerful sacred sites, allowing us in on their valuable perspective millennia into the future.

Tropical Astrology As An Egregore

Regardless of Tropical Astrology’s accuracy in terms of the actual sky, it has a direct impact on humanity. In fact, its impact has been growing in recent years, with most people than ever learning about astrology in search for support on their path to self-discovery and self-improvement.

The nature of consciousness means that anything that a group of sentient beings focus on will result in the creation of a group mind, or egregore. Both thought energy and emotional energy fuels the creation of an egregore.

What this means is that even if Tropical Astrology, particularly its signs, is not reflecting actual celestial entities as they exist, it still has a discernable and meaningful impact on human consciousness, and especially on those who believe in it. This also ties into the power of our consciousness in shaping Reality and our perception of it.

An idea focused on and believed in by a large group of people becomes, in essence, an autonomous consciousness complex. We can consider Tropical Astrology, or elements of it, to be in this category. This is why it still has meaning and an impact, even if it is not reflecting reality exactly as it is without the interaction of human consciousness.

What Is True Sidereal Astrology?

One of the various zodiac systems and methods used in astrology is employed in true sidereal astrology. Popularized by Athen Chimenti from Mastering the Zodiac, this approach is unique in that it is grounded in the real sky and our position relative to the constellations.

Below is a great primer on what is True Sidereal Astrology:

Get your full True Sidereal astrology report with e-reading

Our solar system’s astronomical rotations, or the Precession of the Equinoxes, cause our alignment with the constellations to fluctuate, so as we complete an annual orbit around the Sun, we never return to our initial position or alignment with the constellations.

Year after year, our cosmic position varies ever so slightly, which causes the dates that the Sun appears in the constellation of Aries to change as well. This movement causes a change of 1º every 70 years when we look up at the night sky. The change is so small that due to human lifespans being short, we barely notice it, at all. However, after 2,000 years, it adds up to be a major difference.

True Sidereal Astrology is a system that is based on where we are in the Solar System overall, not on the seasons that affect us here on Earth. The Precession of the Equinoxes, the Earth’s third rotation, is taken into account by Sidereal and True Sidereal Astrology but not by the Tropical Zodiac.

Let’s look at an example.

Assume for the moment that you were born on March 30th, which is in the sign of Aries in the Tropical Zodiac. The Sun was still in the constellation Pisces when you were born, despite the fact that conventional astrology would have you born with an Aries Sun. For this reason, you would be classified as a Pisces Sun sign by Sidereal and True Sidereal Astrologers.

This may sound confusing. After all, how can you be both a Pisces Sun and an Aries?

The Sidereal and True Sidereal Zodiacs interpret the elements of the charts according to our alignment with the stars, not the seasons, and they respect our ever-changing alignment with the constellations.

When the first day of spring arrives, Sidereal and True Sidereal astrologers will interpret it as such because the Sun is still in the Pisces constellation. The first day of spring will align in the Aquarius constellation in a few thousand years.

These two systems will persist in determining the Zodiac based on our alignment with the stars, rather than the seasonal variations. As of right now, the Tropical and Sidereal/True Sidereal Zodiac systems diverge by one to three complete signs!

Note: While sun signs are different in True Sidereal Astrology vs Tropical and Sidereal, both Houses and Aspects are exactly the same.

There are several variations of astrology beyond the kind popular in the West. For instance, there are different approaches to the House system, as well as the overall structure of the astrology chart.

Every astrological system has its benefits and reasonings. However, depending on your objective, you may find that one astrological system is more suited for you over others.

Zodiac Systems Dates Comparison

Today, there are three main Zodiac systems used in Astrology:

  • Vedic Astrology – uses the Sidereal Zodiac
  • Astronomical or Constellation-based Astrology – uses the True Sidereal Zodiac
  • Mainstream or Western Astrology – uses the Tropical Zodiac

Below is a chart showing the dates for each sign in a few different systems

Here is an index to help you understand each column:

Tropical – Conventional Western (Babylonian) Astrology

Lahiri – The most-used ayanamsa in Vedic astrology. It is often recommended to use this ayanamsa when working with the Vedic system. Other popular options for Vedic include Raman, as well as KP when working with Vedic KP methods.

Fagan-Bradley – The most-used ayanamsa by Western astrologers. Even though the majority of Western astrologers use tropical, many use sidereal. Fagan-Bradley is the most recommended, along with Kanatas. If you are working with mainstream Western astrology, these are the best to start with.

IAU – uses the uneven size of the constellations, and also includes Ophiuchus. It adjusts the sign boundaries to match their actual sizes in the sky. The majority of sidereal systems (including the ones above) use thirty-degree zodiac signs. But, the zodiac signs are different sizes in the sky. The IAU takes this into account.

Midpoint – True Sidereal Astrology as developed by Mastering the Zodiac also uses the actual size of the constellations, like the IAU. But, the IAU boundaries are designed for astronomy, not astrology. The IAU boundaries do not reference the ecliptic (the path of the Sun and planets). Midpoint fixes this by setting the zodiac sizes relative to the ecliptic. It is designed for astrology.


True Sidereal Astrology’s Quantum Connection

While Tropical Astrology essentially ignores the true positions of the celestial beings we call stars, True Sidereal Astrology makes a great effort to ensure it identifies the exact positions. This means True Sidereal Astrology is a fluid and dynamic system that will update as shifts in the constellations continue to occur in the future.

By following where the stars and constellations are, we can then hone in on how the light frequencies from those stars are affecting us on the quantum level.

Saying that Venus was in Cancer when you were born, when it was actually interacting with and reflecting the photons from the Gemini constellation, is going to result in a fundamental difference on the interpretation of that energy and how it affects you throughout your life.

We are all incredibly distinct self-organized fields of consciousness that have materialized on Earth, in this dense form we call the human being. Your energy field contains your distinct light blueprint and pattern. It is based on the dynamics of your natal chart, which demonstrates the precise motion of all photons and all manner of quantum particles and waves, including celestial beings within our solar system and beyond, at the moment you took your first inhale as a distinct human being in this life.

We could also consider the implications of the light of larger stars having a more profound affect on us than smaller ones, along with what each individual star within a predefined constellation does to our energetic template and consciousness when compared with what they do together.

However, there’s no need to get too into the weeds as, at the end of the day, astrology is not a religion, but instead a tool and a guide. It need not be dogmatic nor make us more neurotic and controlling.

As long as we understand the basics of how to read our natal charts in Tropical, Vedic, True Sidereal, or some other astrological system, we can gleam helpful insights and reflections about our current state that can assist us in our journey of self-discovery and self-improvement.

How to Read Your True Sidereal Chart

First, you will need your sidereal birth chart. You can see the Sun, Moon, and planets exactly as they appeared in the sky during your birth, with this handy chart calculator.

Once you have your chart, you can use this easy guide to read your birth chart. Within minutes, you will have an in-depth understanding of your chart and what it says about you.

You can also simply get your ~20 page full True Sidereal astrology report with in-depth e-reading to get an in-depth detailed report of your chart.  


Astrology comes in a wide variety of forms, including ones we did not go over, like Mayan and Chinese Astrology. At the end of the day, astrology is the ancient language of the stars, and it is in our DNA, as well as our birthright, to explore our human experience through the stars above, allowing them to give greater meaning to our lives and how we are inherently affected by them.

There are many tools we can use to learn more about ourselves, including systems like Human Design, Gene Keys, the Mayan Dreamspell Calendar, the I Ching, and others, with likely many more to be created in the future.

We could say that, overall, True Sidereal Zodiac is more in line with subconscious dynamics, whilst the Tropical Zodiac is more in sync with our ego dynamics. All astrological systems have value and function.

The Zodiac is a spectrum that stretches from Aries to Pisces and from separation to oneness, with each degree of the 360º circle holding a unique energy. The energy of 5º Cancer differs from that of 20º Cancer.

It helps to see the Zodiac as an energy cycle rather than becoming fixated on artificial boundaries that shift across systems. Just because the Zodiac changes doesn’t mean that your identity does. The many Zodiacal systems offer diverse viewpoints on energy dynamics and your human experience. You are a complex and multidimensional soul transcending the zodiacal limitations of the human ego-driven experience.

Bottom Line: Regardless of which Zodiacal system you are using, the signs that the elements of your chart are in are the ONLY things that alter. The house position and the aspect relationships between the planets remain unchanged. In any system, it would stay the same. For example, if at the time of your birth, Mercury were squaring Mars in the Solar System, it would have no impact on the house of your sign. The Solar System’s planetary positions remain constant. The Zodiac sign they are affiliated with is the only thing that changes.

How Is Your Chart Affected by the True Sidereal Zodiac?

Are you interested in learning how the True Sidereal Zodiac affects your chart?

To compute your natal chart using the True Sidereal approach, utilize Mastering the Zodiac’s free online chart calculator here or get a full in-depth chart analysis and report here.