The Sun is Luminary of the daytime. It shines a spotlight on whatever it touches.
In synastry, the house the Sun falls in shows the area of life in which someone shines a spotlight in the life of another person.
This spotlight can be positive or negative depending on the charts of the two people involved.
To learn how to do a full synastry reading, see:
Sun in 1st House Synastry
If someone's Sun is in your 1st House, it will create an instant connection. They will respond to you immediately and will tend to see themselves in you.
While this configuration will open the door to a potential relationship, it may or may not lead to anything deeper. A lot will depend on what else is happening between the two charts.
One potential downfall to the Sun in your 1st House is that this person could tend to overshadow or eclipse you. You could feel like they are always in the limelight when you are together.
Sun in 2nd House Synastry
When someone's Sun is in your 2nd House, they shine a spotlight on your sense of self-confidence and self-worth. They also focus your attention on material matters, such as money and possessions.
The Sun itself is neutral, neither positive nor negative. Because of this, the person may give you confidence or they may rob you of your confidence. In many cases, it is a little of both.
Sun in 3rd House Synastry
The Sun in the 3rd House in synastry is usually good for relationships. It tends to promote good communication between people.
Regardless of the actual relationship, this person will feel like a sibling or close family relation. In a romantic relationship, this will be the boy or girl "next door."
The downside is that in a romantic relationship, there may be a lack of excitement or sexual chemistry.
Sun in 4th House Synastry
In synastry, the Sun in the 4th House represents someone who touches you on a very deep level. This is someone who, for good or for ill, will trigger your childhood memories.
This could be someone who reminds you of one of your parents, and you may act out some of your family dramas with this person.
While this relationship can be uncomfortable at times, it can also be quite healing. In order to make this relationship healthy, you will have to look at your "stuff" from childhood and work through it.
Sun in 5th House Synastry
You will greatly enjoy the company of someone whose Sun is in your 5th House. They will bring out your playful side.
In a romantic relationship, this placement will produce sexual chemistry.
This is a person that you can relax around and just be yourself.
If you are quiet or shy, this person will help bring you out of your shell. If you are more extroverted, this person will help you release any excess energy.
This person will naturally bring out your creativity, and it will be easy to have fun when they are around.
Sun in 6th House Synastry
It can be hard for you to find common ground with someone whose Sun is in your 6th House, especially early on in the relationship. This person will tend to see your faults and may be quick to point them out.
In most cases, someone whose Sun is in your 6th House will not become a romantic partner. There will be exceptions, especially if there are other more positive synastry configurations between your charts.
The same is true for close friendships and other relationships that are created by choice. If this person is a family member, it will likely be one that you have trouble getting along with.
Sun in 7th House Synastry
This person is your natural partner. You will complement and balance each other.
The two of you will be very different from one another, but that can be a strength rather than a weakness.
You may find that you clash with this person on a regular basis. It is possible that this person will become your nemesis rather than your partner.
Even if this is the case, however, you will find that your connection with this person will help define you even as it challenges you.
Sun in 8th House Synastry
If someone's Sun is in your 8th House, they will naturally tap into your deepest, darkest secrets. Yet, they will rarely do so in a way that feels safe or comforting.
Indeed, there is always an element of danger with someone whose Sun touches your 8th House.
You will want to take care when you are around this person. Even if their intentions are good, they cannot help but bring out the things in you that you would prefer to hide.
On the positive side, this relationship can be healing in its own way, whether or not it lasts. If you have the courage to be honest with yourself and face your shadow, you can learn valuable lessons from this person.
Sun in 9th House Synastry
A person whose Sun is in your 9th House will broaden your horizons. They will challenge you, but they will do so in a way that is fun and exciting.
You will enjoy being in this person's company.
Your relationship with this person will be an adventure. The nature of this adventure will depend on the signs involved.
It could be a physical adventure involving travel. On the other hand, it could just as easily be an adventure of the mind or of the spirit.
In any case, you will learn a great deal from this person.
Sun in 10th House Synastry
Someone whose Sun is in your 10th House will have a strong impact on your reputation and social standing. They will take an interest in your career.
This impact can be positive or negative depending on the other ways in which the two charts interact.
This could be someone who pushes you in your career. The person may serve in a mentor capacity for you in some way.
On the negative side, this could also be someone who tries to control you or someone who tends to overshadow or eclipse you.
Sun in 11th House Synastry
A person whose Sun is in your 11th House will be an ally. They will have a natural interest in your well-being.
Regardless of what other connections you have with this person, there will be a strong element of friendship between you.
This person can help you achieve your goals. They will tend to care about the same things that you do.
You will enjoy being in this person's company.
Sun in 12th House Synastry
If someone's Sun is in your 12th House, they can see things about you that you cannot see in yourself.
This relationship can be healing, but it can also be destructive if you are not careful.
The 12th House is the House of Self-Undoing, and this person can tempt you into escapism or other negative behaviors.
On the positive side, this person will also shine a light on your unconscious. They can also lead you towards spiritual development.