Retrograde grahas in a chart
A retrograde graha in the chart is marked with R. Retrograde is an apparent motion from Earth, and the classical texts give it various meanings, some of them about the strength or the manner of the graha's effect.
What it is
The traditional view varies: some schools consider a retrograde planet stronger, and others consider it weaker in some respects. The site does not apply a strength rule for retrograde planets.
How it is worked out or read
The site marks a graha retrograde when its longitude a day later is smaller than today's. Sun, Moon, Rahu and Ketu are never marked.
Where it appears on this site
The R marks appear in the birth chart. The retrograde article explains the apparent motion.
Retrograde as an apparent motion
Retrograde motion is an apparent backward movement of a planet against the stars as seen from Earth. It happens because Earth overtakes the planet, or because the planet is passed by Earth, and it does not reflect any real reversal of the planet's own path. The apparent motion lasts for weeks at a time, and it recurs at regular intervals for each planet that can retrograde.
In a birth chart a retrograde planet is marked with R, which shows that the planet was moving backward on the day of birth. This simple mark is the basis of the reading, and the reader then considers what the classical texts say about retrograde planets in general.
Which planets can retrograde
Mars, Jupiter and Saturn retrograde when the Earth passes them on the inner track. Mercury and Venus, which orbit inside Earth's orbit, retrograde as they pass Earth. The Sun and Moon never retrograde, and Rahu and Ketu are not marked, since the mean node always moves backward by definition. A reader who sees an R beside a planet should therefore know that the planet is one of the five that can retrograde.
The retrograde periods of Mercury and Venus are the most frequent in the cycle, and those of Saturn the least frequent. This is because Saturn is so slow that its retrograde period is seen against the stars for a long while before it returns.
What the classical texts say
Classical readings give retrograde planets several meanings. Some describe a retrograde planet as stronger in certain respects, because it is said to be working inward. Others describe it as weaker, because its motion is unusual and its expression is less direct. Many schools read a retrograde planet as turning its energy toward the themes of its house in a more reflective way.
Because the views differ, the reader should state which view is taken. The site does not apply a strength rule for retrograde planets, and it leaves the choice to the reader and to any practitioner the reader consults.
Checking a retrograde mark
The site marks a graha as retrograde when its longitude one day later is smaller than its longitude today. A reader who doubts a mark can compute the longitude for two consecutive days using the ephemeris or the birth chart tool and compare them. This check confirms the mark and shows how close the planet is to its turning point, which can be read as the degree of its stationary phase.