top of page

Relationship Astrology Techniques: Synastry, Composite, Davison, and Coalescent Charts

While astrology can be an incredible tool for individual awareness, it can also shed a lot of clarity on relational dynamics. One of the ways I see astrology as being useful is through chart comparison. We can see what someone lights up in us or comes alive through our relating. In astrology several techniques exist for this inquiry whether it be for exploring between romantic partners, business partners, family members, or friends.

In my relationship sessions with clients, I do my best to focus on what is the charts in a matter of fact way. The charts tell us potential, not necessarily future. I've seen thousands of charts together, some that looked amazing and two people couldn't seem to make it work...and others where I couldn't' find the relationship glue and yet they seemed incredibly happy.

However, it's important to remember that compatibility in astrology is not a fixed determination. Instead, it provides a framework to understand the potential strengths and weaknesses of a relationship. Relationships thrive on communication, compromise, and mutual growth, and the birth chart aspects are just one piece of the puzzle.

For this reason, with clients I often suggest not to look at anyone's chart until 6 months of knowing someone, or as a tool for reflection once it ends rather than prediction before it begins.

While we often associate relationships with romance, all of the techniques below can be applied to any type of relationship, including friendships, family dynamics, and even professional collaborations. By analyzing the charts with these techniques between two individuals, astrologers can offer valuable insights into the nature of their interactions, helping them navigate challenges and capitalize on their strengths.

To me relationships help us understand ourselves and others, we gain a deeper appreciation for the complexity of human connections and the potential for growth and transformation through shared experiences and astrology can help.


Synastry Charts: You v. me

One of the most sought-after insights in synastry is compatibility. By examining the aspects between planets, astrologers can identify areas of resonance and tension between two people. While harmonious aspects might indicate ease and understanding, challenging aspects can suggest areas where conflicts or misunderstandings might arise.

Synastry is the art and science of comparing two or more birth charts to understand the potential interactions and dynamics between individuals. Birth charts, also known as natal charts, are graphical representations of the positions of celestial bodies at the exact time and location of a person's birth. These charts are like cosmic snapshots, capturing the unique cosmic energy imprinted upon an individual at the moment of their arrival into the world.

In synastry, the primary focus is on the relationships between the planets in one person's chart and the planets in another person's chart. These relationships are known as aspects. Aspects describe the angular relationships between planets, showcasing how they communicate and influence each other's energies.

For instance, a conjunction occurs when two planets are close together in the same sign or house, intensifying their combined effects. A trine, on the other hand, suggests a harmonious connection, while a square signifies potential challenges and conflicts that stimulate growth and transformation. Each aspect adds a layer of complexity to the relationship, unveiling the unique dynamics that individuals bring to each other's lives.


Composite Chart: personality of the relationship, symbolic, collaboration and purpose

After a certain amount of time, two charts weave something new, this is where the composite chart comes in.

This composite chart, often referred to as the "relationship chart," provides a unique lens through which we can explore the dynamics and potential of any partnership, be it romantic, familial, or professional.

The composite chart is born from the harmonious fusion of the birth data of two individuals, creating a singular chart that represents the energy, essence, and potential of the relationship itself. This chart is calculated by finding the midpoints between the corresponding planets and points of both individuals and constructing a new chart based on these midpoints. The result is a symbolic representation of the relationship, revealing its intrinsic qualities and challenges.

Every aspect, planet, and house placement in the composite chart has a profound impact on the dynamics between the two individuals. The planetary aspects, such as conjunctions, oppositions, trines, and squares, mirror the varying degrees of compatibility and challenge present within the relationship. The house placements highlight the areas of life where the partnership's energies are most likely to manifest. For example, a composite Sun in the 7th house might suggest that the relationship's focus is on partnership and collaboration.

Just as in individual birth charts, the planets in the composite chart embody distinct archetypes and energies. The composite Sun signifies the essence and purpose of the relationship, while the Moon reflects its emotional undercurrents. Mercury governs communication and intellectual exchange, Venus represents love and harmony, Mars embodies passion and action, and so forth. By delving into the planetary placements, an astrologer can decode the intricate cosmic dance occurring within the partnership.

The composite chart doesn't remain static; it evolves over time just as relationships do. The transits and progressions to the composite chart provide valuable insights into the ebb and flow of energies within the partnership. Transits can spark significant events, while progressions illuminate the long-term evolution of the relationship's dynamics. Observing these celestial movements allows astrologers to offer guidance and insight during pivotal moments in the partnership's journey.

Every relationship has its challenges, and the composite chart is no exception. Challenging aspects in the composite chart can indicate areas of friction, miscommunication, or differing needs. However, these challenges also hold the potential for growth and transformation. Through understanding the cosmic dynamics at play, partners can work together to navigate these challenges and harness the potential for mutual evolution.

It is through the wisdom of the composite chart that we uncover the hidden cosmic bonds that unite two souls on their shared journey through life's enigmatic cosmos.


Davison Chart: mid-points in space and time

In the world of astrology, the Davison Chart is a hidden gem, a celestial tapestry that weaves the energies of two individuals into a single, unique chart. Named after its creator Ronald C. Davison, this chart holds the secrets of a relationship's dynamics, potentials, and challenges.

The Davison Chart was devised as a response to this question. It's constructed by finding the midpoint between two individuals' birth dates, times, and places. This midpoint becomes the birth moment for the relationship itself, creating a chart that is representative of the unique energy shared between two people.

At the heart of the Davison Chart lies the idea that a relationship is a separate entity, with its own character and destiny. Just as two musical notes create a new harmony when played together, the energies of two individuals combine to form a new cosmic melody in the Davison Chart. Planets, houses, and aspects in this chart reflect the qualities, challenges, and potentials that emerge from this cosmic union.

In the Davison Chart, the positions of planets take on profound significance. The conjunctions, oppositions, trines, and squares between the planets create a narrative of the relationship's dynamics. Harmonious aspects might signify shared goals, understanding, and ease of communication, while challenging aspects could point to areas of conflict and growth. For instance, a Venus-Mars trine might indicate a strong physical and emotional attraction, while a Sun-Saturn square could point to tests and lessons in the relationship.

The houses in the Davison Chart reveal where the energies of the relationship are focused. The placements of planets within these houses offer insights into the areas of life that will be most affected by the relationship's presence. The 7th house, representing partnerships, gains even more significance in this chart. Planets located here shed light on the qualities that the relationship brings out in each person and how the partnership impacts their individual lives.


Coalescent Chart: harmonics and events

The Coalescent Chart, developed by Lawrence Grinnell, is a technique for analyzing astrological relationships and very lesser known. I've been trying to learn it myself and haven't been able to find out much about the technique. This 20th century method involves assigning harmonics to planets and operates akin to a composite chart. By examining the relative positions of celestial bodies, the Moon's Nodes, and the Midheaven in a pair of natal charts, Coalescent Charts provide insights into transit sensitivity, shedding light on the dynamics between two individuals. To determine the harmonic, one calculates the shortest arcs in both birth charts and divides the angles into 360. The planet's position is then multiplied by the harmonic figure to initiate the assessment of compatibility. For more detailed information, you can refer to this source.

These charts are utilized to highlight an exceptional responsiveness to transits, making them valuable tools for fostering connections between individuals or for understanding the connection between a person and a significant event. I don't use this technique in sessions, but appreciate its modernity.


In the end, all of the techniques above serve as a reminder that, just as the stars influence us, we also have the power to shape our interactions and relationships. It's a blend of fate and free will, offering a celestial roadmap to navigate the ever-changing landscape of human connections. So, whether you're exploring a new romance, nurturing a friendship, or collaborating with colleagues, astrology can provide a guiding light to help you navigate the cosmic dance of relationships.

1 Comment

Dana Stjernfelt
Dana Stjernfelt
Jun 04

I think more astrologists should look at the Davidson chart. I only recently discovered it myself. Up until then, I had been focusing on composite charts when doing my readings. mars conjunct neptune synastry

bottom of page