<!--QuoteBegin-->QUOTE<!--QuoteEBegin-->what are the kinds of astrology?? one is rashi based and other nakshatra based as far as i know. could someone elucidate these two - i mean what eaxctly is a rashi and whats a nakshatra?? and how are these different from the "zodiac" system of the Greeks/westerners??<!--QuoteEnd--><!--QuoteEEnd-->
Mathematically speaking:
Full revolution = 360 degrees = 2 pi radians
A sidereal year is about 360 days (Actually 365.2564 days) hence the measurement of "degree" came around - Sun "moves" around a degree each day..
And you have 12 months in a year (Month = synodic month - from new moon to new moon = 29.53 days ) - So another way to divide full revolution is rashi's (same as Zodiac) - 12 Rashis... (360/12 = 30 degrees apart) .. son moves around 1 rashi each month.
Another practical way to divide full circle is to see how much moon moves each day
Since sidereal month is around 27 (actually a little over 27.32 days) so we divide the ecliptic in 27 equal parts , these are called 27 naxatras (Because sidereal month is a little over 27 days .. some Hindu astonomers added one more naxatra)
Each Naxatra is (360/27 = 13+1/3 degree.
So in one sense (mathematically speaking) you can use any measurement .( US ephemeris uses degree/minutes/seconds .. mathematician use radians .. ) it makes no difference in calculations...
Astrologically - Western "sign" (Eg "Leo"/"Singh" rashi) is based on solar position (Means sun is at that particular location) while Rashi/ naxtra (Or Hindu panchang) is based on lunar position (on that particular day what is the position of moon)
So say, Vrishib Rashi Position (Called Taurus or Bull in Zodica) is essentially same as Rohini Naxtra--- as far as ecliptic is concerned .. But you are a Taurus if the position of sun was in Taurus - while for Rashi that day the moon has to be near the stat Aldebaran)
(Actually in the zodiac based on "tropical" year "Taurus" is no longer near star Aldebaran - It was 2500 years ago, now it is almost more than a rashi away! - see the next para)
A little complication comes because of difference between "tropical" and "sidereal" ..
(Western is "tropical" year based) Hindu is mainly sideral .. (In sanskrit it's Nirayan or Sayan but most of Hindu astronomers use sidereal) ... Basically with sidereal - these are positions of actual stars/rashis and not degrees counted from vernal equinox (The difference is due to precession of equinoxes) ...
Hope that helps. Any good book on Astronomy could be used.
Name of Naxtras:
Ashwini Pushya Swati Sravana Bharani Ashlesha Vishakha Dhanishtha Krittika
Magha Anuradha Satabisha Rohini Poorvaphalguni Jyeshta Poorvabhadrapada
Mrigashirsa Uttaraphalguni Moola Uttarabhadrapada Ardra Hasta Poorvashada
Revati Punarvasu Chitra Uttarashadha
Mathematically speaking:
Full revolution = 360 degrees = 2 pi radians
A sidereal year is about 360 days (Actually 365.2564 days) hence the measurement of "degree" came around - Sun "moves" around a degree each day..
And you have 12 months in a year (Month = synodic month - from new moon to new moon = 29.53 days ) - So another way to divide full revolution is rashi's (same as Zodiac) - 12 Rashis... (360/12 = 30 degrees apart) .. son moves around 1 rashi each month.
Another practical way to divide full circle is to see how much moon moves each day
Since sidereal month is around 27 (actually a little over 27.32 days) so we divide the ecliptic in 27 equal parts , these are called 27 naxatras (Because sidereal month is a little over 27 days .. some Hindu astonomers added one more naxatra)
Each Naxatra is (360/27 = 13+1/3 degree.
So in one sense (mathematically speaking) you can use any measurement .( US ephemeris uses degree/minutes/seconds .. mathematician use radians .. ) it makes no difference in calculations...
Astrologically - Western "sign" (Eg "Leo"/"Singh" rashi) is based on solar position (Means sun is at that particular location) while Rashi/ naxtra (Or Hindu panchang) is based on lunar position (on that particular day what is the position of moon)
So say, Vrishib Rashi Position (Called Taurus or Bull in Zodica) is essentially same as Rohini Naxtra--- as far as ecliptic is concerned .. But you are a Taurus if the position of sun was in Taurus - while for Rashi that day the moon has to be near the stat Aldebaran)
(Actually in the zodiac based on "tropical" year "Taurus" is no longer near star Aldebaran - It was 2500 years ago, now it is almost more than a rashi away! - see the next para)
A little complication comes because of difference between "tropical" and "sidereal" ..
(Western is "tropical" year based) Hindu is mainly sideral .. (In sanskrit it's Nirayan or Sayan but most of Hindu astronomers use sidereal) ... Basically with sidereal - these are positions of actual stars/rashis and not degrees counted from vernal equinox (The difference is due to precession of equinoxes) ...
Hope that helps. Any good book on Astronomy could be used.
Name of Naxtras:
Ashwini Pushya Swati Sravana Bharani Ashlesha Vishakha Dhanishtha Krittika
Magha Anuradha Satabisha Rohini Poorvaphalguni Jyeshta Poorvabhadrapada
Mrigashirsa Uttaraphalguni Moola Uttarabhadrapada Ardra Hasta Poorvashada
Revati Punarvasu Chitra Uttarashadha