First the zodiac was divided into twelve rasis,( zodiac sign ) to study the effects of the planets placed there. Then the ancient seers added another sub divisional system of breaking down the zodiac into 27 Nakshatras or star constellations. Each nakshatra has a span of 13 degrees and 20 minutes. After that each nakshatra was further subdivided into 4 Padas, or quarters, of 3 degrees and 20 minutes. Hence the first zodiac sign Aries, which has 30 degrees, contains the entire 4 padas (13:20') of the 1st star constellation Ashwini, the entire 4 padas (13:20') of the 2nd star constellation Bharani and the 1st pada (3:20') of the third star constellation Krittika. So each rasi contains total 9 padas. These nakshatras belong to three main groups: Deva or divine, Manusha or human and Rakshasa or Demonic. They have different ruling deities, owned by different planets and have divergent qualities. Hence while studying the effects of a planet placed in Aries, it is also studied in which nakshatra it is placed and in which pada of that nakshatra it is placed. This system of analysis exists only in Indian astrology.

No.	Nakshatra(Star)	Longitude Sign-Deg- Min	Lords
1	Aswini	00-00-00	Ketu
2	Bharani	00-13-20	Venus
3	Kritika	00-26-40	Sun
4	Rohini	01-10-00	Moon
5	Mrigasira	01-23-20	Mars
6	Aridra	02-06-40	Rahu
7	Punarvasu	02-20-00	Jupiter
8	Pushya	03-03-20	Saturn
9	Aslesha	03-16-40	Mercury
10	Magha	04-00-00	Ketu
11	Poorvaphalguni	04-13-20	Venus
12	Uttaraphalguni	04-26-40	Sun
13	Hasta	05-10-00	Moon
14	Chitra	05-23-20	Mars
15	Swati	06-06-40	Rahu
16	Visakha	06-20-00	Jupiter
17	Anuradha	07-03-20	Saturn
18	Jyehsta	07-16-40	Mercury
19	Moola	08-00-00	Ketu
20	Poorvashadha	08-13-20	Venus
21	Uttarashadha	08-26-40	Sun
22	Sravana	09-10-00	Moon
23	Dhanshita	09-23-20	Mars
24	Satabisha	10-06-40	Rahu
25	Poorvabhadrapada	10-20-00	Jupiter
26	Uttarabhadrapada	11-03-20	Saturn
27	Revati	11-16-40	Mercury

Following is the list of the nine planets ( Nav Grahas) their names nature and the important things they represent.
Sun (Surya)		Moon (Chandarma)
Nature	the King	Nature	the Queen
Exalted	Aries	Exalted	Taurus
Debilitated	Libra	Debilitated	Scorpio
Friends	Moon,Mars,Jupiter	Friends	Sun, Mercury
Enemies	Venus, Satin	Enemies	None
Body Part	Right Eye	Body Part	Left Eye
Mahadasha	6 years	Mahadasha	10 Years
Gem	Ruby	Gem	Pearl
Numerology	1	Numerology	2
Mantra	Om ghrani suryay namah	Mantra	Om som somay namah
Mars (Mangal)		Mercury (Budha)
Nature	The commander	Nature	The Prince
Exalted	Capricorn	Exalted	Virgo
Debilitated	Cancer	Debilitated	Pisces
Friends	Sun, Moon, Jupiter	Friends	Sun, Venus
Enemies	Mercury	Enemies	Moon
Body Part	Muscles	Body Part	Skin
Mahadasha	7 years	Mahadasha	17 year
Gem	Red Coral	Gem	Emerald
Numerology	9	Numerology	5
Mantra	Om ang angarkaya namah	Mantra	Om bum budhaya namah
Jupiter (Brahaspati)		Venus (Shukra)
Nature	The Guru	Nature	An Adviser
Exalted	Cancer	Exalted	Pisces
Debilitated	Capricorn	Debilitated	Virgo
Friends	Sun, Moon, Mars	Friends	Mercury, Saturn
Enemies	Venus, Mercury	Enemies	Sun, Moon
Body Part	Fat	Body Part	Sexual Organs
Mahadasha	16 Years	Mahadasha	20 year
Gem	Yellow Sapphire	Gem	Diamond
Numerology	3	Numerology	6
Mantra	Om bram brahaspataye namah	Mantra	Om shum shukraya namah
Satin (Shani)		Rahu
Nature	Liberation	Nature	Serpent
Exalted	Libra	Exalted	Taurus
Debilitated	Aries	Debilitated	Scorpio
Friends	Venus, Mercury	Friends	Mercury, Venus, Saturn
Enemies	Sun, Moon, Mars	Enemies	Jupiter
Body Part	Nerves	Body Part	Nerves
Mahadasha	19 Year	Mahadasha	8 Year
Gem	Blue sapphire	Gem	Gomeda
Numerology	8	Numerology	None
Mantra	Om sham shanesharaya namah	Mantra	Om ram rahuve namah
Ketu
Nature	Liberation
Exalted	Scorpio
Debilitated	Taurus
Friends	Mercury
Enemies	None
Body Part	Nerves
Mahadasha	7 Year
Gem	Cats eye
Numerology	None
Mantra	Om kem ketave namah