The Stars
The Bundahishn Chapter 2 states that the stars (visible to the eye) number 6,480,000.

Constellations of the Zodiac, the Dwazdah-Dkhtaran
The twelve constellations, are:
  • Varak (the ram) (Aries),
  • Tora (the bull) (Taurus),
  • Do-patkar (the two-figures) (Gemini),
  • Kalachang (the crab) (Cancer),
  • Sher (the lion) (Leo),
  • Khushak (ear of grain) (Virgo),
  • Tarazhuk (the balance) (Libra),
  • Gazdum (the scorpion) (Scorpio),
  • Nimasp (the centaur) (Sagittarius),
  • Vahik/Nahazik (the lead goat) (Capricorn),
  • Dul (the water-pot) (Aquarius), and
  • Mahik (the fish) (Pisces).

World Horoscope - Zaych-i Gehan
Image credit: K. E. Eduljee, Zoroastrian Heritage

Chief Stars of the Cardinal Point Sectors
The chief stars of the cardinal point sectors are:
  • Tishtar (Av. Tishtriya) (commonly identified with Sirius), chief of the eastern sector and guardian of the rains (the direction from which the rains came in ancient Iran?),
  • Sataves/Sadwes (Av. Satavesa) (Fomalhaut?), chief of the South,
  • Vanand (Av. Venant) (Antares? Vega?), the chief of the West,
  • Haptoring/Haftoreng (Av. Haptoiringa) (Ursa Major), the Seven Bears or Seven Thrones, is the chief of the North and it is from this region that the advesary entered. From each of the seven points, a band extends to each of the seven regions (continents) of the eart.

Rapithwan, is the Lord of Mid-Heaven, the throne and the chiefs. The sector of the Great One is also called a gah, one of the five periods of the day. More specifically it is the Rapithwan Gah, the period that lasts from noon to 3 p.m. during the seven warm Rapithwan months of the year. (Also see Divisions of the Day at our Zoroastrian Heritage page on the Calendar.

Parand, Mazd-tat, and others on the list above are also chiefs of the directions. The Greater Bundahishn states "astronomers call these stars of the directions and sectors leaders, and classify them according to magnitude based on size and brightness: first, second and third magnitude for big, medium and small."

The GB (2.19) further states that "Tishtar, Besn, Taraha, Azara, Pateywar, and Pesh-Parviz are of very swift motion."

Lunar Mansions
The spaces traversed by the moon, generally called lunar 'mansions', are listed in the Bundahishn as the khurdak-i hamarikan, the 'sub-divisions of the calculators'. They are:

Padevar, Pesh-Parviz, Parviz, Paha, Avesar (Aze-sar), Beshn, Rakhvad (Rakhvat), Taraha, Avra (Azara), Nahn, Miyan (Maian), Avdem, Mashaha, Spur (Spor), Husru, Srob (Sroi), Nur, Gel (Gelu), Garafsha Varant, Gao, Goi, Muru, Bunda, Kahtsar, Vaht, Miyan (Mayan), and Kaht.

According to E. W. West, SBE Vol 5, the sub-division Parviz is thought to include the Pleiades (Indian Nakshatra Ktittika). This correspondence leads to the identification of the first sub-division Padevar with Nakshatra Ashvini. Further, Lesser Bundahishn Chapter 7.1 mentions Avrak (Avra) as in the ninth sub-division.

Heavenly Bodies
Lesser Bundahishn 5.1; The seven heavenly bodies that correspond to/oppose the seven chiefs of the constellations are:
  • Planet (abakhtar/abakharig or starag) Tir (Mercury) with Tishtar, chief of the East,
  • Planet Ohrmazd-i Ab (Jupiter) with Haptoring/Haftoreng, chief of the North*,
  • Planet Warharan/Wahram-i Ab (Mars) with Vanand, chief of the West*,
  • Planet Anahid-i Ab (Venus) with Sataves/Sadwes, chief of the South,
  • Planet Kevan (Saturn) with the great one of the middle (peg) of the sky (i.e. North Star?), the lord of the chiefs, and
  • Comets Gochihr and Mushpar, provided with tails unto the Sun and Moon. Mushpar is attached to the Sun that it may do less harm.
*B.T.Anklesaria's translation of the Greater Bundahishn (GB) has these two associations transposed at 5A.3 and 4.

GB 5.4 and 5A.3 note two dark bodies (tamigan - eclipses or antithesis?), the Dark Sun (Mihr-i Tamig) and Dark Moon as the antithesis of the Sun (Khwarsheed) and Moon (called Mah-i Gospand-Tomag, Moon of the seed of life/kine) respectively.

GB 5A.8: The planets are bound to the Sun: Jupiter, Saturn and Mars are bound at a distance of 180° from the Sun, Mercury at a distance of 1,860' (31°)*, and Venus at a distance of 2,831' (47°11')  from the Sun.(*Prof. Henning emends the text to read 1,650'=27°30".) These figures are surprisingly accurate.

GB 5A.9: The planets are called abakhtaran because they are ne akhtar, not stars.

Motion of the Planets. Orbits
Planets of the Solar System. Image Credit: Monarch Library
Since the orbits of the planets visible to the eye from the earth are approximately on the same plane, when they are observed from the earth, the planets also appear to move along or close to the ecliptic.

The Moon's orbit is tilted by 5° with respect to the ecliptic.

Kinds of Motion
There two two kinds of 'motion' ascribed to the planets, one is its daily motion along the ecliptic from east to west. The other is the drift or shift in position or segment in the sky an observer finds the planet and the same time each night. This drift or shift in position relative to the stars appears to move the other way, that is from west to east.

The east to west daily motion is due to the rotation of the earth around its axis. The west to east drift or shift in position is because of the orbit of the earth and planets around the Sun.

While the observer may find the stars in approximately the same place the next night, shifting slowly from west to east over the year, the observer will finds the planets have shifted their relative position towards the east more rapidly.

For the observers in ancient times, this rapid shifting made the planets stand apart from the stars. In addition, some planets appeared to drift or shift faster than others and to complicate matters further, the direction of the shift could change from west-east to east-west. This reversal in drifting or shifting is called retrograde motion.
Prograde or Direct Motion
Direction of the Orbits of the Solar System's Planets. Mercury and Pluto have orbits inclined to the disc-like plane of the orbits of the other planets
Image credit: Science Clarified
Since the visible planets also orbit the Sun in the same anti-clockwise direction as do the earth, when seen from the earth, they also appear to travel in the same east to west direction as the Sun, Moon and stars. This east to west motion is called prograde or direct motion.

In addition, planets further away from the Sun tend to make fewer orbits around the Sun than do the inner planets. For instance, Jupiter (closer to the Sun) therefore make 2 1/2 rotations while Saturn (further from the Sun) makes one. From the earth, this makes it look like the inner planets are travelling faster.

Sidereal Period
When it comes to travelling through the twelve segments of the ecliptic, the Sun passes through all the segments once a year, Jupiter passes through them once about every twelve years (actually 11 years 315 days = 11.862 years), and Saturn once every 30 years (actually 29 years 167 days = 29.458 years).

The sidereal period of a planet is the time it takes for the planet to return to the same position with respect to the stars, e.g. from one position on its orbit back to the same position.

Synodic Period
The synodic period of a planet is the time it takes for the planet to return to the same position with respect to the Sun, e.g. from an inferior conjunction with the Sun back to another inferior conjunction with the Sun. The Synodic period for Jupiter is 398.9 days while that for Saturn is 378.1 days.

Retrograde Motion
Diagram of the cause of Venus' retrograde motion when viewed from the earth. Image credit:  Science U
Ever so often, a planet when viewed from the earth appears to change its shifting motion from west-east to east-west. The east-west shift is called retrograde motion, retrograde meaning a backward step.

The retrograde motion of Mars explained. Image credit: Wikipedia

The retrograde motion of Mars as plotted in the sky. Image credit: Wikipedia

The apparent retrograde motion of Mars in 2003 as plotted in the sky.
Image credit: Wikipedia
In the moving diagram from Science U above, the diagram to the left shows an exaggerated view of Venus (both in size and shift speed) as seen from the earth on different nights of the year. The image on the right shows the corresponding position of Venus and the Earth on their orbits around the Sun. We see that from the position represented by the fourth and fifth lines from the left to the position represented by the ninth line, Venus appears to move from the left to the right (i.e. east to west) while at other times it is shifting from west to east.

As we have stated above, this east-west shift is called retrograde motion and happens at the point when the faster orbiting Venus overtakes the Earth.

The above is an example of when an inner planet to the Sun, Venus, appears to retrograde its shift when viewed from Earth, the outer planet from the Sun.

Mars, is a planet that has an orbit further away from the Sun than does the earth. When it is on the same side of the Sun as the Earth (see diagram to the right), in other words when it is opposite the Sun (and therefore viewable at night) in a so-called superior position, it's positional shift in the night sky appears to retrograde while the faster orbiting earth 'overtakes' Mars.

Astrologers call positions 2, 3 and 4 in the diagrams to the left as Mars in retrograde. Position 1 and 5 are Mars in prograde or direct motion.

According to Wikipedia, the more distant planets retrograde more frequently:
  • Mars retrogrades for 72 days every 25.6 months.
  • Jupiter for 121 days (about 4 months) every 13.1 months or about 9 months after the end of the previous retrograde.
  • Saturn for 138 days every 12.4 months.
  • Uranus for 151 days every 12.15 months and
  • Neptune for 158 days every 12.07 months.
The period between such retrogradations is the synodic period of the planet (see above).

Milky Way & Comets
GB 5B 22: There is a feature (dakhshag) in the sky called Rah-i Kawosan (Path of Kayus) has the brilliance of the dragon (breh-i) Gochihr, the serpent of the cosmos.

The myth of the abortive flight of King Kayus to the heavens is recounted in the Denkard 9.21 and in Ferdowsi's Shahnameh. Elsewhere in Persian literature, the Milky Way  is called (Rah-e) Kah-Kashan, the (path of the) chaff-draggers. MacKenzie: The Milky Way crosses the ecliptic roughly at the first points of Cancer and Capricorn, with its own 'first points' in Gemini and Saggitarius and can also be thought of as a dragon or a serpent.

The reappearance of the comet Gochihr will portend the commencement of the end times.
Occupants of the October night sky in the Northern Hemisphere
Image Credit: starrysigns.com